taxonID	type	description	language	source
03A587ED3239FFD383E9FF182D8DFD36.taxon	description	The genus Aegialomys comprises four species, A. baroni (Allen 1897), A. galapagoensis (Waterhouse 1839) (that includes A. bauri (Allen 1892 )), A. ica (Osgood 1944), and A. xanthaeolus (Thomas 1894), that inhabit the northern Trans-Andean South America, in a region that extends from central – southern Ecuador to Southern Peru, including in its range the Galapagos Archipelago (Weksler et al. 2006; Prado & Percequillo 2013; Percequillo 2015 a; Prado & Percequillo 2016; Prado & Percequillo 2018). Gardner & Patton (1976) described the karyotypes of A. bauri and A. xanthaeolus as essentially identical in all aspects (2 n = 56, FN = 58). However, the same specimens karyotyped and identified as A. xanthaeolus by Gardner & Patton (1976) were recently reviewed by Prado & Percequillo (2016), highlighting that these specimens belong to A. baroni and A. ica. Moreover, as Prado & Percequillo (2018) synonymized A. bauri under A. galapagoensis, the karyotype of the former was attributed tentatively to the latter. Karyotype: 2 n = 56 and FN = 58. Autosomal complement: two small metacentric and submetacentric pairs, and 25 acrocentric pairs (one distinctly large and the remaining large to small decreasing in size). Sex chromosomes: X, a large acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 6, Fig. 2 D). The karyotypes of A. xanthaeolus was currently unknown.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3239FFD383E9FC842CD7FB02.taxon	description	Monotypic genus represented by A. savamis (Malygin, Aniskin, Isaev & Milishnikov 1994), known from only a few specimens collected in Ecuador and northeastern Peru, Departamento Loreto and Departamento Ucayali (in the Sierra del Divisor), near the Peruvian-Brazilian border (Malygin et al. 1994; Weksler & Valqui 2015; Chiquito & Percequillo 2016). Karyotype: 2 n = 50 and FN = 62. Autosomal complement: four submetacentric pairs (three large and one small), two small metacentric pairs, one small subtelocentric pair, and 17 acrocentric pairs (seven large to small and ten very small). Sex chromosomes: X, a metacentric (the largest chromosome of the complement); Y, a large metacentric (Malygin et al. 1994, Fig. 6 I). C- and G-banding were also performed (Malygin et al. 1994; O’Brien et al. 2006, pp. 194).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3239FFD383E9F9642EF3F8EE.taxon	description	Karyotype: 2 n = 60 and FN = 74. Autosomal complement: eight biarmed pairs (one large and seven small), and 21 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small acrocentric (Bonvicino et al. 2014, pp. 529, Fig. 3).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3239FFD283E9F8902FF3FF3E.taxon	description	Karyotype: 2 n = 54 and FN = 66. Autosomal complement: seven metacentric and submetacentric pairs (three large and four small), and 19 acrocentric pairs (one large and the remaining medium to small). Sex chromosomes: X, a large subtelocentric; Y, was a medium acrocentric (Tavares et al. 2011, pp. 651, Fig. 4). The same diploid number was reported by Bonvicino et al. (2014, pp. 529, Fig. 10), but the authors reported a different fundamental number of 62 and 63, due to a presence of two small acrocentric pairs instead of two small submetacentrics, and due to a pericentric inversion involving one chromosome of a small autosome pair.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3239FFD383E9FAD02FEAF9B2.taxon	description	The genus Cerradomys comprises eight species, namely: C. akroai (Bonvicino, Casado & Weksler 2014), C. goytaca (Tavares, Pêssoa & Gonçalves 2011), C. langguthi (Percequillo, Hingst-Zaher & Bonvincino 2008), C. maracajuensis (Langguth & Bonvincino 2002), C. marinhus (Bonvincino 2003), C. scotti (Langguth & Bonvincino 2002), C. subflavus (Wagner 1842), and C. vivoi (Percequillo, Hingst-Zaher & Bonvincino 2008). These species occur in the open vegetation belt that crosses South America from north-eastern Brazil to south-eastern Bolivia and north-western Paraguay (Weksler et al. 2006; Percequillo et al. 2008; Prado & Percequillo 2013; Percequillo 2015 b). All cytogenetic data available for the genus was presented on Table 2, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 2.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3238FFDD83E9FAD52EAFFEDA.taxon	description	Another karyotype for C. langguthi was reported by Nagamachi et al. (2013, pp. 8, Fig. 5) for a specimen from Agropalma Farm, Moju, Pará, Brazil. Karyotype: 2 n = 46 and FN = 62. Autosomal complement: nine biarmed pairs (four large and five medium to small decreasing in size), and 13 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, with the exception of one large metacentric pair. One medium acrocentric pair presented a heterochromatic band on proximal region of its long arm. The X chromosome presented a large heterochromatic block on the proximal region and a small band near to the distal region. The Y chromosome was almost entirely heterochromatic except for the proximal region. G-banding was also performed. FISH with telomeric sequences revealed signals at the ends of all chromosome arms, and additional telomeric sequences were found in three biarmed pairs: one pair with five interstitial telomeric sequence (one on the short arm and four on the long arm), and the others with one interstitial telomeric sequence on the centromeric regions. The authors established maps of chromosomal homology between C. langguthi and Hylaeamys megacephalus using whole chromosome probes of H. megacephalus. The results showed a huge genomic reorganization between the karyotype of these two species.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3237FFDD83E9FE8C28B1FE16.taxon	description	Karyotype: 2 n = 58 and FN = 60. Autosomal complement: one medium subtelocentric pair, one small metacentric pair, and 26 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small metacentric (Langguth & Bonvicino 2002, pp. 291, Fig. 3 C; Bonvicino et al. 2014).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3237FFDD83E9FE38297DFDA6.taxon	description	Karyotype: 2 n = 56 and FN = 54. Autosomal complement: 27 acrocentric pairs decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric (Bonvicino 2003, pp. 84, Fig. 2; Bonvicino et al. 2014).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3237FFDD83E9FD482D2EFB2E.taxon	description	The same diploid number was reported by Bonvicino et al. (1999), Langguth & Bonvicino (2002) and Bonvicino et al. (2005). These authors reported a different fundamental number of 72 due to a presence of one medium subtelocentric pair instead of a medium acrocentric one, and two males carrying one additional B chromosome. These variation in fundamental number occurs sympatrically on specimens collected in Goiás, state of Brazil (Table 2, Fig. 2).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3237FFDD83E9FAD028F8F81A.taxon	description	Another karyotype with 2 n = 54 and FN = 64 was reported by Paresque et al. (2004) and Moreira et al. (2009). The difference in the fundamental number was due to the presence of one small metacentric pair instead of an acrocentric one. Moreira et al. (2009), presented another morphology for the Y chromosome, being a medium metacentric. These variations in diploid and fundamental number of C. subflavus occurs sympatrically on specimens collected in Bahia, Espírito Santo, Minas Gerais and São Paulo, states of Brazil (Table 2, Fig. 2).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3233FFD983E9FF5028CFFCD2.taxon	description	The same karyotype was reported by Pereira & Geise (2007). The authors reported a different fundamental number of 66 due to the presence of one small metacentric pair instead of an acrocentric one. Furthermore, they reported a specimen with 2 n = 51, with one large acrocentric chromosome without homologous and one more pair of small acrocentric chromosomes. The basic diploid number of 2 n = 50 was also reported by Percequillo et al. (2008), who also reported a different fundamental number of 62 due to a presence of one small acrocentric pair instead of a metacentric one, these authors also found a fundamental number of 63 in one male and one female, due to a pericentric inversion involving one chromosome of a medium autosome pair. Another difference was related with the size of Y chromosome smaller on these samples. These variation in diploid and fundamental number of C. vivoi occurs sympatrically on specimens collected in Bahia and Minas Gerais, states of Brazil (Table 2, Fig. 2).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3233FFD983E9FC842D4AFC2A.taxon	description	Karyotype: 2 n = 46 and NF = 56, unpublished data (J. F. S. Lima), mentioned by Bonvicino et al. (2014, pp. 531, Table I). This karyotype seems to be the same reported by Maia & Hulak (1981) for samples from Pernambuco, Brazil (Table 2). However, it was not possible to compare the two karyotypes, since metaphase plate of the former was not available.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3233FFD983E9FBF82CCBFA22.taxon	description	Monotypic genus represented by D. albimaculatus (Percequillo, Weksler & Costa 2011), all known specimens were from the eastern slopes of the Serra do Mar, in the coastal Brazilian Atlantic Rainforest from Rio de Janeiro to Santa Catarina states (Percequillo et al. 2011; Delciellos et al. 2015). Karyotype: 2 n = 62 and FN = 62. Autosomal complement: one small metacentric pair, and 29 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a large submetacentric slightly smaller than the X (Suárez-Villota et al. 2013, pp. 68, Fig. 1; Delciellos et al. 2015). C-banding metaphases exhibited pericentromeric constitutive heterochromatic blocks on all autosomes and on the long arm of Y. G-banding was also performed. FISH with telomeric sequences revealed signals at the ends of all chromosomes, and additional telomeric sequences were found on the pericentromeric region of both X and Y chromosomes (Suárez-Villota et al. 2013).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3233FFD883E9F8522F33FED9.taxon	description	Karyotype: 2 n = 80 and FN = 86. Autosomal complement: four small metacentric and submetacentric pairs, and 35 acrocentric pairs (one distinctly large and the remaining large to small decreasing in size). Sex chromosomes: X, a very large subtelocentric; Y, a small acrocentric (Musser et al. 1998, pp. 237, Fig. 109). According to Musser et al. (1998), some acrocentric autosomes have short second arms and could be classed as biarmed, but the FN was based on classifying them as uniarmed chromosomes (if these pairs were classified as biarmed, the FN of this species would be 90, but this review considers the FN = 86).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3233FFD983E9F9EB2D98F8A1.taxon	description	The genus Euryoryzomys comprises six species, E. emmonsae (Musser, Carleton, Gardner & Brothers 1998), E. lamia (Thomas 1901), E. legatus (Thomas 1925), E. macconnelli (Thomas 1910), E. nitidus (Thomas 1884), and E. russatus (Wagner 1848). The species inhabit forests throughout the cis Andean tropical and subtropical lowlands of South America, including Amazonia, the Guianas, southeastern Brazil, eastern Bolivia, northern Argentina, and eastern Paraguay (Musser et al. 1998; Weksler et al. 2006; Percequillo 2015 c). All cytogenetic data available for the genus was presented on Table 3, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 3.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3232FFD883E9FE8C2841FC2A.taxon	description	The same karyotype and two different cytotypes for this species were reported by Andrades-Miranda et al. (2000) for specimens from Goiás, Brazil. Cytotype 1: 2 n = 64 and FN = 84. Autosomal complement: 11 biarmed pairs large to small decreasing in size, and 20 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large subtelocentric; Y, unknown as only as two females were analyzed. Cytotype 2: 2 n = 60 and FN = 84. Autosomal complement: 13 biarmed pairs large to small decreasing in size, and 16 acrocentric pairs (one large and the remaining small). Sex chromosomes: X, a large subtelocentric; Y, unknown as only a female was analyzed. C-banding metaphases exhibited pericentromeric constitutive heterochromatic blocks on all autosomes and on the X chromosomes (Andrade-Miranda et al. 2000, pp. 466, 3 B and C). According to the authors, the two different cytotypes reported differs in that presented by Bonvicino et al. (1998), because they present karyotypes with six additional (cytotype 1) and two extra (cytotype 2) pairs of small acrocentric and less three pairs and one pair of biarmed chromosomes, respectively. This decrease of the number of acrocentric pairs suggests that Robertsonian rearrangement could differentiate the three cytotypes of E. lamia (Andrades-Miranda et al. 2000). The first karyotype described for this species (2 n = 58 and FN = 84) was reported only for specimens collected in the northern region of Goiás, states of Brazil (Table 3, Fig. 3), whereas the cytotype 1 (2 n = 64 and FN = 84) and cytotype 2 (2 n = 60 and FN = 84) occur sympatrically in the southern region of this same state (Table 3, Fig. 3).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3231FFDA83E9F8CA287EFC9A.taxon	description	The same diploid number was described by Musser et al. (1998, pp. 231, Fig. 105) for populations from western Brazil, with a different fundamental number. Karyotype: 2 n = 64 and FN = 70. Autosomal complement: four medium to small metacentric and submetacentric pairs, and 27 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric (Musser et al. 1998). According to the authors, the karyotype of the Peruvian specimen, reported by Gardner & Patton (1976) has the same diploid number, but because the Brazilian animals have four pairs of biarmed autosomes instead of the single pair reported for the Peruvian animal, the fundamental number was 70 instead of 64. Additional preparations from Peruvian specimens may show the reported differences to be an artefact of the poor quality of original chromosomal slides (Musser et al. 1998). The specimens collected in Venezuela by Musser et al. (1998, pp. 231, Fig. 105) presented another different karyotype. Karyotype: 2 n = 76 and FN = 85. Autosomal complement: five small metacentric and submetacentric pairs, 31 acrocentric pairs large to small decreasing in size, and two unpaired chromosomes, a medium-sized metacentric and a medium-sized acrocentric. Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric. According to the authors, several pairs of acrocentric autosomes bear discernible second arms and could be classed as biarmed chromosome, thus raising the FN to as high as 107 (Musser et al. 1998). Another different karyotype was mentioned by Patton et al. (2000, pp. 143), from samples for Rio Jaú, Amazonas. Karyotype: 2 n = 58 and NF = 90, the information was not available in literature, as Patton et al. (2000) informed that this represents unpublished data provided by M. N. F. Silva. These variation in diploid and fundamental number of E. macconnelli occurs in different localities of Amazon rainforest (Table 3, Fig. 3).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3230FFDA83E9FC4C2F19FB02.taxon	description	Karyotype: 2 n = 80 and FN = 86. Autosomal complement: four small metacentric pairs, and 35 acrocentric pairs (one distinctly large and the remaining large to small decreasing in size). Sex chromosomes: X, a very large subtelocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 4, Fig. 1 E; Patton et al. 2000). A different morphology of sex chromosomes was reported by Volobouev & Aniskin (2000), a submetacentric X and a metacentric Y chromosome. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The short arm of X and the Y were entirely heterochromatic. G-banding was also performed (Volobouev & Aniskin 2000). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva et al. 2000).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3230FFDA83E9FB342E28F9B2.taxon	description	Karyotype: 2 n = 80 and FN = 86. Autosomal complement: four small metacentric pairs and 35 acrocentric pairs large to small decreasing in size. Sex chromosomes: X chromosome presented three different morphologies, a large metacentric, a large submetacentric, and a large subtelocentric; Y chromosome presented three different morphologies, a medium submetacentric, a medium-small subtelocentric, and a small acrocentric. The differences on the X chromosome morphology, apparently was due to heterochromatin variation since the C-bands can occur on the centromeric region or the whole short arm can be heterochromatic. NORs bands were detected in two to four small acrocentric pairs. G-banding was also performed (Andrades-Miranda et al. 2000, pp. 465, Fig. 2 D). This same karyotype was also reported by Silva et al. (2000), Paresque et al. (2004), Pinheiro & Geise (2008), Di-Nizo et al. (2014), and Gatto-Almeida et al. (2016). A female with 2 n = 80 / 81 being an XX / XXX mosaic was reported by Andrades-Miranda et al. (2000).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3230FFC583E9F9642820FE4E.taxon	description	A new karyotype for the genus was described by Silva et al. (2000). Karyotype: 2 n = 76 and FN = 86. Autosomal complement: six metacentric pairs (two large and four small), and 31 acrocentric pairs decreasing in size from large to small. Sex chromosomes: X, a large subtelocentric; Y chromosome presented two different morphologies, a medium submetacentric (Ya), and a medium acrocentric (Yb). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The short arm of X and the entirely Y chromosome were heterochromatic. G-banding was also performed. Multiple NORs, varying from four to nine were localized at the telomeric regions of the short arms of small acrocentric chromosomes. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva et al. 2000, pp. 220, Fig. 1). According to the authors, the karyotype of E. macconnelli (2 n = 76, FN = 85) from Venezuela (Musser et al. 1998) was different from Euryoryzomys sp. nov., because in the former there was no large metacentric chromosomes, and there was five metacentric small pairs while in the latter karyotype, two large metacentrics was observed as well as four small metacentric pairs. Sex chromosomes was also distinctive between both karyotypes (Silva et al. 2000). We present a different karyotype for the genus, here referred as Euryoryzomys sp. The cytogenetic analysis was performed for three males collected in Rio Japurá, Amazonas, Brazil (Table 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322FFFC483E9F9572E9BFEDA.taxon	description	Karyotype: 2 n = 58 and FN = 92. Autosomal complement: 18 biarmed pairs large to small decreasing in size, and 10 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small submetacentric (Fig. 4 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. One large submetacentric pair presented a pericentromeric heterochromatin block that extend to the short arm. The X chromosome presented the short arm entirely heterochromatic and an interstitial lightly stained C-band on its long arm. The Y chromosome presented the long arm entirely heterochromatic (Fig. 4 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 4 C). FISH with telomeric sequences revealed signals at the ends of all chromosome arms, and additional telomeric sequences were found on the centromeric regions of one large and one small biarmed pairs (Fig. 4 D). This karyotype could be a variation of E. macconnelli (2 n = 58 and NF = 90) mentioned by Patton et al. (2000, pp. 143), and the difference in fundamental number resulted from a pericentric inversion involving one biarmed autosomal pair. However, was not possible to compare these two karyotypes since the metaphase plate of the karyotype mentioned by Patton et al. (2000) was not available.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC483E9FD482FF3FD36.taxon	description	Karyotype: 2 n = 54 and FN = 62, the X and Y were submetacentric. This karyotype was reported by Gardner & Patton (1976, pp. 26, Table 2), who listed it without a detailed description.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC483E9FCD82898FC46.taxon	description	Karyotype: 2 n = 54 and FN = 68 – 70, the morphology of the X and Y were undetermined, unpublished data (M. L. Bueno, M. Gómez-Laverde & V. Delgado) mentioned by Gómez-Laverde et al. (2015).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC483E9FEA9281AFDA6.taxon	description	The genus Handleyomys was described by Voss et al. (2002) to accommodate two species, H. fuscatus (Allen 1912), and H. intectus (Thomas 1921), both endemic to the North-Andean region, inhabiting the montane forests of the Andes in Colombia. H. fuscatus were from the western Andes and specimens of H. intectus were from the central Andes. However, they can also be found in semi-natural environments, mainly in pastures and agricultural areas associated with the remaining forest (Voss et al. 2002; Prado & Percequillo 2013).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC483E9FC152FEAFACA.taxon	description	The genus Holochilus comprises six recognized living species, H. brasiliensis (Desmarest 1819), H. chacarius (Thomas 1906), H. lagigliai (Pardiñas, Teta, Voglino & Fernández 2013), H. sciureus (Wagner 1842), H. venezuelae (Allen 1904), and H. vulpinus (Brants 1827). The genus was distributed from central Argentina and Uruguay in the south to northern Venezuela and the Guianas in the north and from the Amazonian regions of Bolivia, Peru, Ecuador, and Colombia to the Atlantic coast of eastern Brazil (Musser & Carleton 2005; D’Elía et al. 2015; Gonçalves et al. 2015). All cytogenetic data available for the genus was presented on Table 4, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 5.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC483E9FAFC2F54F9EA.taxon	description	Karyotype: 2 n = 40 and FN = 56. Autosomal complement: eight biarmed pairs large to small decreasing in size, one small metacentric pair, and 10 small acrocentric pairs. Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of eight acrocentric pairs, and two biarmed pairs. The X chromosome presented constitutive heterochromatin on the centromeric region and on the short arm, while the Y chromosome presented a distal half heterochromatic region. G-banding was also performed (Freitas et al. 1983, pp. 16, Fig. 4).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322EFFC783E9F99C2899FDA6.taxon	description	Karyotype: 2 n = 48 and FN = 56. Autosomal complement: five metacentric pairs (four large and one small), and 18 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, with the exception of one large metacentric pair. The X chromosome presented pericentromeric heterochromatic blocks, the Y chromosome was almost entirely heterochromatic. G-banding was also performed (Nachman & Myers 1989, pp 6668, Fig. 1 A). The karyotype of H. chacarius was highly variable, with diploid number ranging from 48 to 55, and fundamental number from 56 to 60. This variation occurs within and between populations from Paraguay and Argentina (Table 4, Fig. 5), and was resulted from multiple Robertsonian translocations (Nachman & Myers 1989; Nachman 1992 a). Furthermore, two different types of supernumerary chromosome were reported: B 1 was a small to large metacentric or submetacentric chromosome that contains only centromeric heterochromatin, and B 2 was a small acrocentric chromosome that was largely heterochromatic. The authors reported a pericentromeric inversion of a single X chromosome in one female, terminal euchromatic addition to the short arm of the X chromosome in nine specimens, euchromatic addition adjacent to the pericentromeric region in one autosomal pair of two specimens, and one female with only one X chromosome (Nachman & Myers 1989; Nachman 1992 a). In the original report, Nachman & Myers (1989), and latter Nachman (1992 a), considered the fundamental number as the number of all chromosome arms, including sex and B chromosomes. Here the fundamental number was given as the number of autosomal arms, excluding sex and supernumerary chromosomes. A karyotype with 2 n = 48 and FN = 60, was reported by Gardner & Patton (1976) for a sample from Paraguay, however this specimen presented a submetacentric X chromosome, that accounts for the difference from the former karyotype. Vidal et al. (1976) reported a karyotype variation for genus Holochilus, 2 n = 50 – 54 and FN = 56 – 60, for samples from Argentina that seems to belong to H. chacarius. We assumed this correlation, as this variability of diploid and fundamental number was described only for H. chacarius, and due to the proximity of collection localities.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322DFFC683E9F9BB2FFFFD42.taxon	description	Supernumerary chromosomes of H. sciureus were isolated by flow-sorted and used as probe for understand the origin of B chromosomes in tribe Oryzomyini. In situ hybridization of Bs and sex chromosomes of H. sciureus were performed on metaphases of 15 species of Oryzomyini, five of which had Bs. The results revealed that 12 of the species sampled, all belonging to a monophyletic Oryzomyini subclade (clade C and D, recovered by Weksler 2006), were positive for an anonymous ‘ Oryzomyini’ shared heterochromatic region (OSHR) on the X and Y chromosomes. The OSHR was also present on Bs of H. sciureus, Nectomys rattus, and N. squamipes, but not on Bs of Oligoryzomys flavescens, and Sooretamys angouya. Two distinct additional OSHR / autosome associations were observed on S. angouya. According to the authors, the OSHR possibly arose 3.0 to 7.8 million years ago on the sex chromosomes of an ancestral species and spread through the action of transposable elements. These results suggest that the diversity of Oryzomyini Bs in number, size, morphology, and genetic content may be explained by their independent origin in different subgroups of species (Ventura et al. 2015).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322CFFC683E9FD742DF2FB02.taxon	description	Karyotype: 2 n = 44 and FN = 56. Autosomal complement: seven metacentric pairs (six large to medium decreasing in size and one small), and 14 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric. Variation in diploid number (2 n = 42 – 44) were reported due to centric fusions affecting acrocentric pairs, besides the presence of one or two medium-sized supernumerary metacentric chromosomes (Aguilera & Perez-Zapata 1989, pp. 200, Fig. 2; Sangines & Aguilera 1991). These variation in diploid number and the presence of supernumerary chromosomes occurs sympatrically on specimens collected in Portuguesa, state of Venezuela (Table 4, Fig. 5). C-banding metaphases showed that five metacentric pairs had very little pericentromeric heterochromatin, while one medium metacentric pair showed a conspicuous band on the pericentromeric region. The small metacentric pair presented a large pericentromeric heterochromatic block extending to the arms. All acrocentric autosomes presented bands on the pericentromeric region, except for one medium-sized pair, which showed no C-bands. The X chromosome possesses two bands, a thick one on the pericentromeric region and another one on the distal region. The Y chromosome was completely heterochromatic. The small metacentric B chromosomes were almost entirely heterochromatic except for the telomeres. G-banding was also performed (Sangines & Aguilera 1991).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322CFFC683E9FB342F67F8C2.taxon	description	Karyotype: 2 n = 36 and FN = 56. Autosomal complement: 11 metacentric and submetacentric pairs large to small decreasing in size, and six small acrocentric pairs. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric. The acrocentric short arm was frequently visible on the X chromosome, but not on the Y. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented constitutive heterochromatin on the pericentromeric region, while the Y chromosome was largely heterochromatic. G-banding was also performed. Furthermore, one to three supernumerary chromosomes were reported. All B chromosomes were small acrocentric, and largely heterochromatic. The authors reported an addition of euchromatin to the short arm of one X chromosome in a single female, plus one female with only one X chromosome (Nachman 1992 a, pp. 13, Fig. 4). In the original report Nachman (1992 a) considered the fundamental number as the number of all chromosome arms, including sex and B chromosomes. Here the fundamental number was given as the number autosomal arms, excluding sex and supernumerary chromosomes. Riva et al. (1977) reported a karyotype variability of 2 n = 36, 37 and FN = 56, 57 for samples from northern Argentina. These karyotypes seem to belong to H. vulpinus, because this variability of diploid and fundamental number was described only for H. vulpinus species, and because of the collection locality.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED322CFFC283E9F8F42CC2FF3E.taxon	description	A detailed analysis of Robertsonian rearrangements on meiosis of Holochilus species was reported by Nachman (1992 b) and more details about the karyotype evolution and variability of the genus was reported by Aguilera et al. (1993).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3228FFC283E9FE8D2C87FD6E.taxon	description	The genus Hylaeamys comprises seven species, namely H. acritus (Emmons & Patton 2005), H. megacephalus (Fischer 1814), H. oniscus (Thomas 1904), H. perenensis (Allen 1901), H. seuanezi (Weksler, Geise & Cerqueira 1999), H. tatei (Musser, Carleton, Gardner & Brothers 1998), and H. yunganus (Thomas 1902). These species were distributed in moist forests of cis-Andean tropical and subtropical lowlands and foothills from Venezuela and the Guianas southward throughout Amazonia and the Atlantic rainforest to Paraguay and northern Argentina (Weksler et al. 2006; Brennand et al. 2013; Percequillo 2015 d). All cytogenetic data available for the genus was presented on Table 5, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 6.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3228FFCD83E9F9042936FCD2.taxon	description	Karyotype: 2 n = 54 and FN = 62. Autosomal complement: five metacentric and submetacentric pairs medium to small decreasing in size, and 21 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric (Perez-Zapata et al. 1986; Svartman & Almeida 1992 b, pp. 965, Fig. 1; Musser et al. 1998; Andrades-Miranda et al. 2000; Bonvicino et al. 2005; Nagamachi et al. 2013). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented pericentromeric heterochromatic blocks and two interstitial blocks on its long arm. The Y chromosome presented strongly heterochromatic bands on its long arm. G- and R-banding were also performed (Baker et al. 1983; Svartman & Almeida 1992 b; Nagamachi et al. 2013). Multiple NORs, varying from five to ten were localized at the telomeric regions of the short arms of acrocentric autosomes (Svartman & Almeida 1992 b). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observe. Additionally, whole chromosome probes were made for H. megacephalus by flow cytometry from sorted chromosomes of fibroblast cell cultures (Nagamachi et al. 2013). These probes were used to established maps of chromosomal homology between H. megacephalus and Cerradomys langguthi (Nagamachi et al. 2013); Neacomys sp. A, Neacomys sp. B (Silva et al. 2017); Neacomys sp. (cytotype A, and cytotype B), Neacomys sp. E, N. paracou, and N. spinosus (Silva et al. 2019); Oecomys catherinae (Malcher et al. 2017); Akodon montensis and Thaptomys nigrita (Suárez et al. 2015); and Necromys lasiurus and Akodon sp. (Pereira et al. 2016). The results showed a huge genomic reorganization between the karyotype of these species. A different diploid number of 50 was reported by Nagamachi et al. (2013), for a fetus from a specimen from Pará. The fluorescent in situ hybridization with whole chromosome probes of H. megacephalus (2 n = 54 and FN = 62) revealed that chromosome rearrangements in the fetal karyotype was due to X chromosome monosomy, an isochromosome, and heterozygosis for two centric fusions. The authors concluded that the fetal karyotype was not a new cytotype and suggests that the fetus probably would be non-viable or infertile, as widely reported in humans. The same diploid number (2 n = 54) with a different number of arms was reported for samples from Suriname, with the fundamental number of 58 – 59 (Table 5, Fig. 6) (Koop et al. 1983; Kerridge & Baker 1990), and for samples from French Guiana with the fundamental number of 64 (Table 5, Fig. 6) (Volobouev & Aniskin 2000).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3227FFCD83E9FCFA2DAEFB94.taxon	description	Karyotype: 2 n = 52 and FN = 62. Autosomal complement: six metacentric and submetacentric pairs medium to small decreasing in size, and 19 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric (Maia 1990, pp. 379, Fig. 1 A; Andrades-Miranda et al. 2000). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes and on the X chromosome. The Y chromosome was entirely heterochromatic. G-banding was also performed. Multiple NORs, varying from five to nine were localized at the telomeric regions of the short arms of acrocentric pairs (Andrades- Miranda et al. 2000).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3227FFCD83E9FBBB2F5AFA1C.taxon	description	The karyotype of H. oniscus and H. perenensis were very similar, however H. perenensis exhibits a distinctly large acrocentric chromosome that was not present in H. oniscus.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3227FFCD83E9F9CF2FF1F831.taxon	description	A similar karyotype was reported by Andrades-Miranda et al. (2000) for samples from Bahia, Brazil. Karyotype: 2 n = 48 and FN = 64. Autosomal complement: one large subtelocentric pair, eight pairs of biarmed chromosomes large to small decreasing in size, and 14 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a medium acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes and on the X chromosome. The Y chromosome was entirely heterochromatic. G-banding was also performed. Multiple NORs, varying from three to ten were localized at the telomeric regions of the short arms. According to the authors, the difference in the fundamental number of 60 and 64 was due to the morphology of two autosomal pairs. These variation in fundamental number occurs sympatrically on specimens collected in Bahia, state of Brazil (Table 5, Fig. 6). The same diploid number was reported by Geise & Pereira (2008), but the authors did not provide the fundamental number.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC983E9FF502F85FD41.taxon	description	A different karyotype was reported by Gardner & Patton (1976), with 2 n = 60 and FN = 66, the karyotype of this form was nearly identical to that one mentioned before except for the presence of a small metacentric pair. Another karyotype with 2 n = 60 and NF = 64 was reported by Andrades-Miranda et al. (2000). This karyotype was similar to the one reported by Gardner & Patton (1976) (2 n = 60, FN = 66), the difference was due to one more acrocentric pair and one less small biarmed pair, resulting in a FN = 64. Samples from Suriname presented a diploid number from 52 to 59 and fundamental number from 64 to 67 (Koop et al. 1983; Kerridge & Baker 1990). The variation in diploid and fundamental number of samples from Suriname occurs sympatrically, whereas the others karyotypes reported for the genus represent different populations (Table 5, Fig. 6).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC983E9FD112E35FB9E.taxon	description	Monotypic genus represented by L. molitor (Winge 1887), records of extant specimens were from southern South America, predominantly from Uruguay (Voss & Carleton 1993; Prado & Percequillo 2013). Karyotype: 2 n = 52 and FN = 58. Autosomal complement: four metacentric pairs (three large and one small), and 21 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium submetacentric; Y, a small metacentric. Heteromorphism of the X chromosome was reported due to different sizes of short arm. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomal pairs, but was almost absent on the three large metacentric pairs. The X chromosome presented a pericentromeric heterochromatic block. The Y chromosome presented a whole heterochromatic arm. G-banding was also performed (Freitas et al. 1983, pp. 14, Fig. 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC983E9FA282879F9EA.taxon	description	Karyotype: 2 n = 58, G-banding karyotype was performed by Baker et al. (1983).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC983E9F99C2CE3F8C2.taxon	description	Karyotype: 2 n = 56 and FN = 58. Autosomal complement: two small metacentric pairs, and 25 acrocentric pairs (one conspicuously large and 24 medium to small decreasing in size). Sex chromosomes: X, a large subtelocentric (the largest chromosome of the complement); Y, a medium subtelocentric (Gardner & Patton 1976, pp. 10, Fig. 4 B).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC983E9FB6D293EFA06.taxon	description	The genus Melanomys comprises six species, M. caliginosus (Tomes 1860), M. chrysomelas (Goldman 1918), M. columbianus (Allen 1899), M. idoneus (Goldman 1918), M. robustulus (Thomas 1914), and M. zunigae (Sanborn 1949). The species of the genus were found in lowland or lower montane forested habitats in Central America from Honduras to Panama, and south to north-western South America, in Colombia, Ecuador, Peru, and westernmost Venezuela (Musser & Carleton 2005; Hanson & Bradley 2008; Prado & Percequillo 2013; Weksler & Lóss 2015). There was cytogenetic information available only for two species, M. caliginosus and M. chrysomelas.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3223FFC883E9F88C2E14FF3E.taxon	description	Monotypic genus represented by M. transitorius (Hershkovitz 1993), that inhabits the fringe zone between open grassland and bordering scrubland of the Brazilian Cerrado (Hershkovitz 1993; Prado & Percequillo 2013; Paresque & Hanson 2015). Karyotype: 2 n = 38 and FN = 46. Autosomal complement: five small pairs of biarmed elements, and 13 acrocentric pairs decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small submetacentric, as mentioned by Paresque & Hanson (2015).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3222FFC883E9FDE42F88FD36.taxon	description	Karyotype: 2 n = 57 and FN = 58 (fundamental number comprises the number of autosomal and sex chromosomes arms). Chromosomal complement: 27 acrocentric pairs large to small decreasing in size, and three unpaired elements consisting of one large subtelocentric, one large acrocentric, and one small acrocentric. Sex chromosomes was unknown as only a female was examined. This individual was apparently a heterozygous for an autosomal Robertsonian translocation (Gardner & Patton 1976, pp. 10, Fig. 4 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3222FFC883E9FCD82CE1FC46.taxon	description	Karyotype: 2 n = 58, this diploid number was reported by Kiblisky 1969, who listed it without further information.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3222FFC883E9FE8C2FF7FE32.taxon	description	The genus Microryzomys comprises two species, M. altissimus (Osgood 1933), and M. minutus (Tomes 1860). These species were endemic to the northern and central Andes, from northern Venezuela, through Colombia, Ecuador and Peru, to central Bolivia (Carleton & Musser 1989; Carleton 2015).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3222FFC883E9FA282F9FF852.taxon	description	Karyotype: 2 n = 64 and FN = 68. Autosomal complement: three small metacentric pairs, and 28 acrocentric pairs. Sex chromosomes: X, a medium submetacentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome presented the long arm entirely heterochromatic. G-banding was also performed. FISH with 18 s rDNA sequences revealed signals of NOR on the short arm of six acrocentric pairs, and one of these chromosomes also had a NOR on the distal region of the long arm. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva et al. 2015, pp. 4, Fig. 2 C). According to Silva et al. (2015) this karyotype was similar to N. spinosus reported by Patton et al. (2000) (2 n = 64 and FN = 68), except for the morphology of the X chromosome, which was subtelocentric in N. spinosus and submetacentric in N. dubosti. Another diploid number of 62 was reported by Voss et al. (2001) for a sample from Amapá, state of Brazil (Table 6, Fig. 7).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3222FFC883E9FC142FDBFA06.taxon	description	The genus Neacomys comprises 11 species, N. dubosti (Voss, Lunde & Simmons 2001), N. guianae (Thomas 1905), N. macedoruizi (Sánchez-Vendizú, Pacheco & Vivas-Ruiz 2018), N. minutus (Patton, Silva & Malcolm 2000), N. musseri (Patton, Silva & Malcolm 2000), N. paracou (Voss, Lunde & Simmons 2001), N. pictus (Goldman 1912), N. rosalindae (Sánchez-Vendizú, Pacheco & Vivas-Ruiz 2018), N. spinosus (Thomas 1882) (that includes N. spinosus, N. amoenus amoenus (Thomas 1903), and N. a. carceleni (Hershkovitz 1940 )), N. tenuipes (Thomas 1900), and N. vargasllosai (Hurtado & Pacheco 2017). These species occur throughout the Amazon Basin in Brazil, Colombia, Peru, Ecuador, Bolivia, Venezuela, Guyana, Suriname, and French Guiana, and west of the Andes from easternmost Panama to Ecuador and Venezuela. The genus has never been broadly revised and the most recent revisionary efforts were elaborated by Patton et al. (2000) and Voss et al. (2001; see also Prado & Percequillo 2013; Weksler & Bonvicino 2015 a; Hurtado & Pacheco 2017; Sánchez-Vendizú et al. 2018) for western and eastern amazon localities, respectively. All cytogenetic data available for the genus was presented on Table 6, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 7.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321FFFF583E9FB1E2850FAD1.taxon	description	Karyotype: 2 n = 56, the G-banding karyotype was performed by Baker et al. (1983).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321FFFF583E9FAF82FF8FA02.taxon	description	Karyotype: 2 n = 28 and FN = 36. Autosomal complement: five metacentric pairs (one large, one medium, and three small), and eight acrocentric pairs (one large, and seven small). Sex chromosomes: X, a medium submetacentric; Y, a small acrocentric (Sánchez-Vendizú et al. 2018, pp. 16, Fig. 7 C).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321FFFF583E9FA29283EF97B.taxon	description	Karyotype: 2 n = 35 – 36 and FN = 40. Autosomal complement: three small metacentric pairs, and 14 acrocentric pairs (three large, one medium, and the remaining small decreasing in size). The medium-sized element was apparently involved in a Robertsonian polymorphism, with heterozygous individuals found at two different localities, all others localities were homozygous for the acrocentric condition (Table 6, Fig. 7). Sex chromosomes: X, a mediumsmall metacentric; Y, a small acrocentric (Patton et al. 2000, pp. 110, Fig. 75 B).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321FFFF583E9F9222814F83D.taxon	description	There was a misunderstanding about the fundamental number described by Patton et al. (2000): the authors mentioned the fundamental number as being 64 or 68, however if the X chromosome represent one of the mediumsized biarmed elements, the fundamental number of this karyotype was actually 60.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321EFFF483E9FF50296EFDA6.taxon	description	Karyotype: 2 n = 56 and FN = 66. Autosomal complement: six metacentric and submetacentric pairs, and 21 acrocentric pairs. Sex chromosomes: X, a medium subtelocentric; Y, a small acrocentric. Another fundamental number of 62 was reported due to presence of two pericentric inversions (Silva et al. 2015, pp. 4, Fig. A 1 and A 2). This variation in fundamental number occurs in different localities of Pará, state of Brazil (Silva et al. 2015). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented a pericentromeric heterochromatic block. The Y chromosome was almost entirely heterochromatic. G-banding was also performed. FISH with 18 s rDNA sequences revealed signals of NORs on the short arm of five acrocentric pairs, and on the distal region of the long arm of a small acrocentric pair. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva et al. 2015). The same diploid number was presented by Voss et al. (2001). Another fundamental number of 64 was reported by Silva et al. (2019) due to the presence of one acrocentric pair instead of a biarmed pair. The authors also reported a different morphology for the X chromosome, a medium-sized acrocentric.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321EFFF483E9FD482F89FCD2.taxon	description	Karyotype: 2 n = 48 and FN = 50. Autosomal complement: two small metacentric pairs, and 21 acrocentric pairs (one large, and the remaining medium to small decreasing in size). Sex chromosomes: X, a medium submetacentric; Y, a small acrocentric (Sánchez-Vendizú et al. 2018, pp. 16, Fig. 7 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321EFFF483E9FC842FE1FAF6.taxon	description	Karyotype: 2 n = 64 and FN = 68. Autosomal complement: three small metacentric pairs, and 28 acrocentric pairs (one very large, and the remaining large to small decreasing in size). Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 13, Fig. 6 E; Patton et al. 2000, pp. 110, Fig. 75 D). We also report this same karyotype for samples collected in Mato Grosso and in the Rio Içá in Amazonas, states of Brazil, plus a metacentric Y chromosome for the sample from Rio Içá (Fig. 8 A). Furthermore, we performed C-banding for the karyotype with a metacentric Y chromosome, and G-banding and FISH with telomeric sequences for the karyotype with an acrocentric Y. C-banding metaphase exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented pericentromeric heterochromatic blocks and an interstitial lightly stained C-band on its long arm. The Y chromosome was entirely heterochromatic (Fig. 8 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 8 C). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Fig. 8 D). The same karyotype was also reported by Silva et al. (2019) for a sample from Mato Grosso, Brazil, with a different morphology of the X chromosome, a medium submetacentric.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321EFFF483E9FA982E09F9B2.taxon	description	Another different karyotype for a Neacomys species was reported by Aniskin (1994), with 2 n = 30 – 32 and FN = 38, plus 1 to 6 B chromosomes (See also Weksler & Bonvicino 2015 a). Additionally, five karyotypes were described for the genus by Silva et al. (2015, 2017, 2019), for specimens from Pará, Brazil: Neacomys sp. cytotype 1 (Silva et al. 2015; referred as Neacomys sp. D by Silva et al. 2019); Neacomys sp. cytotype 2 (Silva et al. 2015; referred as Neacomys sp. C by Silva et al. 2019); Neacomys sp. A (Silva et al. 2017); Neacomys sp. B (Silva et al. 2017); and Neacomys sp. E (Silva et al. 2019).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321EFFF783E9F96428E0FDA6.taxon	description	Cytotype 2: 2 n = 58 and FN = 64. Autosomal complement: four small metacentric pairs, and 24 acrocentric pairs. Sex chromosomes: X, a medium submetacentric; Y, a small submetacentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, and three biarmed pairs were almostly heterochromatic. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic (Silva et al. 2015, pp. 4, Fig. B 2). These two cytotypes occurs in different localities of Pará, state of Brazil (Silva et al. 2015; Silva et al. 2019). G-banding was also performed. FISH with 18 s rDNA sequences revealed signals of NORs on the distal region of the long arm of three autosomal pairs, one metacentric and two small acrocentric pairs of both cytotypes. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed in either cytotypes (Silva et al. 2015). Silva et al. (2019) established maps of chromosomal homology between cytotype 1, and cytotype 2 of Neacomys sp., by using whole chromosome probes of H. megacephalus. The comparative genomic mapping showed that these cytotypes differs by the presence of blocks of constitutive heterochromatin on the short arms of metacentric chromosomes 22, 23, and 26 of cytotype 1, that was absent on acrocentric chromosomes 22, 24, and 23 of cytotype 2. Di-Nizo et al. (2017) also reported a diploid number of 58 for a Neacomys species from Mato Grosso, state of Brazil, with a different fundamental number of 66 (Di-Nizo et al. 2017, pp. 859, Fig. 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321CFFF683E9FBF82D46F9B2.taxon	description	Maps of chromosomal homology were established between seven karyotypes of Neacomys species (N. paracou (2 n = 56, FN = 64); N. spinosus (2 n = 64, FN = 68); Neacomys sp. (cytotype 1, 2 n = 58, FN = 70; and cytotype 2, 2 n = 58, FN = 64); Neacomys sp. A (2 n = 58, FN = 68); Neacomys sp. B (2 n = 54, FN = 66); and Neacomys sp. E (2 n = 62, FN = 60 )) by using whole chromosome probes of H. megacephalus. The results showed that chromosome diversity between these species were due to 17 fusion / fission events, one translocation, pericentric inversions on four syntenic blocks, and six syntenic autosomal blocks with amplification / deletion of constitutive heterochromatin (Silva et al. 2019). We also presented two different karyotypes for the genus, mentioned here as Neacomys sp. 1 and Neacomys sp. 2. The cytogenetic analyzes was performed for specimens collected on the Rio Japurá and Rio Içá, Amazonas state of Brazil (Table 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321CFFF183E9F9642FE5FF3E.taxon	description	Karyotype: 2 n = 48 and FN = 54. Autosomal complement: four small metacentric and submetacentric pairs, and 19 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X, a medium subtelocentric; Y, a small acrocentric (Fig. 9 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic (Fig. 9 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 9 C). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Fig. 9 D). This karyotype seems to be the same reported by Sánchez-Vendizú et al. (2018) for N. rosalindae. However, these authors appar-ently misclassified two small metacentric pairs as acrocentric. Also, the X chromosome seems to present two different morphologies, a medium submetacentric or subtelocentric. A morphological and molecular analyses of the specimens referred as Neacomys sp. 1 is necessary to test this hypothesis.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321CFFF683E9FF502E77FDFA.taxon	description	Karyotype: 2 n = 58 and FN = 68. Autosomal complement: six metacentric and submetacentric pairs of medium size, and 22 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X, a medium submetacentric; Y, a small submetacentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, three biarmed pairs presented a conspicuous heterochromatic block. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic. G-banding was also performed. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva et al. 2017, pp. 6, Fig. 2). According to the authors, this karyotype was similar to those described by Silva et al. (2015) for specimens identified as Neacomys sp. (2 n = 58 / FN = 70, and 2 n = 58 / FN = 64). The comparative analysis of C-banding revealed that the difference among the three karyotypes were due to blocks of heterochromatin affecting the number of chromosome arms (Silva et al. 2017).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321CFFF683E9FDAC2961FBD6.taxon	description	The authors established maps of chromosomal homology between the karyotype of Neacomys sp. A and Neacomys sp. B by using whole chromosome probes of H. megacephalus. The comparative genomic mapping between the two Neacomys species shows that these karyotypes differs by the occurrence of 11 fusion / fission events, one translocation, four pericentric inversions, and four heterochromatic amplification events (Silva et al. 2017).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321BFFF183E9FA312FCAF85C.taxon	description	Karyotype: 2 n = 54 and FN = 62. Autosomal complement: five medium to small metacentric and submetacentric pairs, and 21 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X, a medium subtelocentric; Y, a small submetacentric (Fig. 10 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome presented the long arm entirely heterochromatic (Fig. 10 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 10 C). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Fig. 10 D). The same diploid number (2 n = 54) and a similar fundamental number (FN = 66) was reported by Silva et al. (2017) for Neacomys sp. B. However, the former karyotype presented five large and two small biarmed pairs, different from the karyotype presented by us that comprises five medium to small biarmed pairs. The sex chromosomes morphology was also distinctly between the two karyotypes.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321AFFF083E9FA0C2945F8C2.taxon	description	The genus Nectomys comprises six species, N. apicalis (Peters 1861), N. magdalenae (Thomas 1897) (that includes N. m. magdalenae and N. m. grandis (Thomas 1897 )), N. palmipes (Allen & Chapman 1893) (that includes N. p. palmipes and N. p. tatei (Hershkovitz 1948 )), N. rattus (Pelzeln 1883), N. saturatus (Thomas 1897), and N. squamipes (Brants 1827). Water rats of the genus Nectomys were found in most lowland rainforest biomes in South America, and in the riverine forests of open habitats, such as the Cerrado, Llanos, and other grasslands (Bonvicino & Weksler 2015; Chiquito & Percequillo 2019). All cytogenetic data available for the genus was presented on Table 7, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 11.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED321AFFF383E9F8F429ABFF12.taxon	description	Apparently, these difference in diploid number could be explained by the occurrence of one or two centric fusions. These variation in diploid number occurs in different populations of Brazil, Ecuador and Perú (Table 7, Fig. 11).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3219FFF383E9FB2E28A3FA54.taxon	description	Karyotype: 2 n = 34 and FN = 40. Autosomal complement: one large metacentric pair, three large submetacentric pairs, and 12 acrocentric pairs (two medium and the remaining small). Sex chromosomes: X, a medium acrocentric; Y, a small submetacentric (Gómez-Laverde et al. 1999, pp. 663, Fig. 1). Another diploid number of 32 was mentioned by Bonvicino & Weksler (2015) as unpublished data obtained by M. L. Bueno.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3219FFF383E9FA062927F93D.taxon	description	Karyotype: 2 n = 16 and FN = 26. Autosomal complement: three metacentric pairs (one distinctly large, one large, and one small), one large submetacentric pair, two subtelocentric pairs (one medium, and one small), and one large acrocentric pair. Sex chromosomes: X, a medium subtelocentric; Y, a small acrocentric. An autosomal polymorphism involving three chromosomal pairs (one distinctly large metacentric, one large acrocentric, and one large submetacentric) resulting in a diploid number 17 and fundamental number of 25, 28 and 29 were reported. These variation in diploid and fundamental number occurs in different localities of norther Venezuela (Table 7, Fig. 11). C- and G-banding were also performed by the authors. The karyotype of N. palmipes exhibited the lowest diploid number of the tribe Oryzomyini and, so far, was described only by Barros et al. (1992, pp. 36, Fig. 3).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3219FFF283E9F8EE281FFD36.taxon	description	Karyotype: 2 n = 52 and FN = 52. Autosomal complement: one small metacentric pair and 24 acrocentric pairs large to small decreasing in size (Gardner & Patton 1976, pp. 13, Fig. 6 B; Maia et al. 1984; Yonenaga-Yassuda et al. 1988; Barros et al. 1992; Bonvicino et al. 1996; Silva & Yonenaga-Yassuda 1998 a; Andrades-Miranda et al. 2001 b; Oliveira & Langguth 2004; Bonvicino et al. 2005). Sex chromosomes: X chromosome presented three different morphologies, a large submetacentric, a large subtelocentric, and a large to medium acrocentric; Y chromosome presented two different morphologies, a medium submetacentric, and a medium to small subtelocentric (Gardner & Patton 1976; Maia et al. 1984; Yonenaga-Yassuda et al. 1988; Barros et al. 1992; Silva & Yonenaga-Yassuda 1998 a; Andrades-Miranda et al. 2001 b; Bonvicino et al. 2005). A different diploid number of 53 to 55 were reported due to the presence of 1 to 3 supernumerary chromosomes. Three different types of supernumerary chromosomes were reported: a large subtelocentric, a medium submetacentric, and a small acrocentric (Maia et al. 1984; Yonenaga-Yassuda et al. 1988; Barros et al. 1992; Silva & Yonenaga-Yassuda 1998 a; Andrades-Miranda et al. 2001 b). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented a large variability on the amount and distribution of heterochromatin that encompass the pericentromeric region, the entirely short arm, and sometimes a lightly band on its long arm. The Y chromosome presented a large variability on the amount and distribution of heterochromatin that encompass the pericentromeric region, the distal portion of the long arm, the whole long arm and a large part of the short arm. C-banding of B chromosomes presented different patterns on the distribution of heterochromatin: entirely heterochromatic, the long arm entirely heterochromatic, or a heterochromatic block on the end of the long arm. G- and R-banding were also performed (Maia et al. 1984; Yonenaga-Yassuda et al. 1988; Silva & Yonenaga-Yassuda 1998 a). Multiple NORs, varying from two to fourteen were localized at the telomeric regions of the short arms of acrocentric pairs (Yonenaga-Yassuda et al. 1988). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva & Yonenaga-Yassuda 1998 a).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3218FFF283E9FCDD2F7EF83D.taxon	description	The species N. rattus and N. squamipes with the basic karyotype (2 n = 52 and 2 n = 56, respectively) were raised in captivity for crossed breeding. Cytologic and histologic analyses of the hybrid meiosis showed that the rearrangements between these two karyotypes represented a drastic reproductive barrier (Bonvicino et al. 1996). According to Yonenaga-Yassuda et al. (1998) based on the G-banding pattern, two tandem fusions have been recognized as the mechanism involved in the differentiation of these karyotypes.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FE382EC1FD6E.taxon	description	Karyotype: 2 n = 70 and FN = 84. Autosomal complement: eight medium to small metacentric and submetacentric pairs, and 26 acrocentric pairs large to small decreasing in size. However, if the largest autosomal pair was considered as a subtelocentric, the FN would be 86. Sex chromosomes: X, a medium metacentric; Y, a small submetacentric (Gardner & Patton 1976, pp. 4, Fig. 1 D).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FD10282EFC29.taxon	description	Karyotype: 2 n = 66 and FN = 90. Autosomal complement: two medium subtelocentric pairs, 11 metacentric and submetacentric pairs medium to small decreasing in size, and 19 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium metacentric; Y, a small subtelocentric (Kiblisky 1969, pp. 1339, Fig. 1; Aguilera et al. 1995). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, some acrocentric pairs presented a lightly stained C-band on distal regions of its long arm. The X chromosome presented a conspicuous pericentromeric heterochromatic block. The Y chromosome was totally heterochromatic. G-banding was also performed (Aguilera et al. 1995).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FBDC2FA0FB66.taxon	description	Karyotype: 2 n = 80 and FN = 92. Autosomal complement: seven medium to small metacentric and submetacentric pairs, and 32 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a very large subtelocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 4, Fig. 1 C).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FB082CCDFAF5.taxon	description	Karyotype: 2 n = 76 and FN = 88, mentioned by Percequillo (2015 e) based on information provided by J. L. Patton.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FA982DFCF9CE.taxon	description	Karyotype: 2 n = 66 and FN = 112. Autosomal complement: 15 medium to small metacentric and submetacentric pairs, nine subtelocentric pairs (one large, four medium, and four small), and eight acrocentric pairs (one large, three medium, and four small). Sex chromosomes: X, a medium metacentric; Y, a small submetacentric (Gardner & Patton 1976, pp. 4, Fig. 1 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFF883E9FF502E30FE15.taxon	description	The genus Nephelomys comprises 13 recognized species, N. albigularis (Tomes 1860), N. auriventer (Thomas 1899), N. caracolus (Thomas 1914), N. childi (Thomas 1895), N. devius (Bangs 1902), N. keaysi (Allen 1900), N. levipes (Thomas 1902), N. maculiventer (Allen 1899), N. meridensis (Thomas 1894), N. moerex (Thomas 1914), N. nimbosus (Anthony 1926), N. pectoralis (Allen 1912), and N. pirrensis (Goldman 1913). These species were restricted to the Andes, from Bolivia to Colombia, the coastal ranges of Venezuela, and extend northwards in the cordilleras of Panama and Costa Rica in Central America (Márquez et al. 2000; Weksler et al. 2006 b; Prado & Percequillo 2013; Percequillo 2015 e).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3212FFFB83E9F9F02902FE32.taxon	description	Another karyotype was also presented by Aguilera et al. (1995), for the samples of western Venezuela, from the Páramo de Tamá. Although distinct from N. meridensis on morphological and karyological traits, specimens of this region were provisionally identified as N. meridensis (Percequillo 2015 e), until subsequent analyses validate or reject this hypothesis. Karyotype: 2 n = 66 and FN = 92. Autosomal complement: one medium subtelocentric pair, 13 metacentric and submetacentric pairs medium to small decreasing in size, and 18 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium acrocentric; Y, unknown as only a female was examined. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, some acrocentric pairs presented a lightly stained C-band on distal regions of its long arm. The X chromosome presented two heterochromatic blocks, one pericentromeric and another distal. G-banding was also performed (Aguilera et al. 1995, pp. 46, Fig. 2 A). Aguilera et al. (1995) analyzed by G-banding these two karyotypes and suggested that the difference in the number of chromosomal arms was possible to be explained due the occurrence of pericentric inversions.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3211FFFB83E9FDE42D3CFD0A.taxon	description	Karyotype: 2 n = 66 and FN = 94. Autosomal complement: nine medium to small metacentric and submetacentric pairs, six subtelocentric pairs (three large and three small), and 17 acrocentric pairs (one large and the remaining medium to small). Sex chromosomes: X, a large acrocentric; Y, a small submetacentric (Gardner & Patton 1976, pp. 4, Fig. 1 B).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3211FFFB83E9FCD8287BFB9E.taxon	description	The genus Nesoryzomys comprises five species, N. darwini (Osgood 1929), N. fernandinae (Hutterer & Hirsch 1979), N. indefessus (Thomas 1899), N. narboroughi (Heller 1904), and N. swarthi (Orr 1938). These species were restricted to the Galápagos Islands, Ecuador, with recent specimens known from only four of the major islands in the archipelago: Isla Baltra, Isla Fernandina, Isla Santa Cruz, and Isla Santiago. One undescribed species known from fragmentary subfossil remains, have been reported from Isla Isabela and Isla Rábida. Of the five species, two were now considered extinct, N. darwini and N. indefessus (Steadman & Zousmer 1988; Prado & Percequillo 2013; Dowler 2015). There was cytogenetic information available only for N. narboroughi.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3211FFFB83E9FB402DBDFAF6.taxon	description	Karyotype: 2 n = 32 and FN = 50. Autosomal complement: eight metacentric and submetacentric pairs large to medium decreasing in size, two subtelocentric pairs (one large and one medium), and five acrocentric pairs (one medium and four small). Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 10, Fig. 4 C).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3211FFFA83E9F8902FA3FC9A.taxon	description	Two different karyotypes were reported by Gomes-Júnior et al. (2016, pp. 409, Fig. 2, and pp. 410, Fig. 3) who characterized them as karyomorph ‘ a’ and karyomorph ‘ b’. Karyomorph ‘ a’: 2 n = 64 and FN = 110. Autosomal complement: eight metacentric pairs large to small decreasing in size, three submetacentric pairs (two large and one small), 13 subtelocentric pairs large to small decreasing in size, and seven small acrocentric pairs. Sex chromosomes: X and Y were medium submetacentrics. Karyomorph ‘ b’: 2 n = 66 and FN = 112. Autosomal complement: six metacentric pairs (two large and four small), five submetacentric pairs (two large and three small), 13 subtelocentric pairs medium to small decreasing in size, and eight small acrocentric pairs. Sex chromosomes: X, a large metacentric; Y, a medium submetacentric. C-banding metaphases, in both karyotypes, exhibited blocks of constitutive heterochromatin, ranging between subtle and conspicuous, on the pericentromeric region of all autosomes. The X chromosome presented a pericentromeric heterochromatic blocks and a lightly stained C-band on both telomeric regions. The Y chromosome presented the long arm entirely heterochromatic. G-banding was also performed. NORs were localized at the telomeric regions of the short arms of one medium and one small autosomal pair of both karyotypes. FISH with 18 S rDNA revealed signals at the telomeric regions of short arms in one medium and one small autosomal pair in both karyotypes, while FISH with 5 S rDNA revealed signals at the pericentromeric region of one large pair of karyomorph ‘ a’, and one medium pair of karyomorph ‘ b’. FISH with telomeric sequences revealed signals at the ends of all chromosomes, and additional telomeric sequences was found on the pericentromeric region of X chromosome in both karyotypes. Another karyotype, with 2 n = 72 and FN = 80, was attributed to this species by Gomes-Júnior et al. (2016) (unpublished data from T. Lira) based on molecular data. However, this karyotype was very distinct from that presented by Gomes-Júnior et al. (2016). In addition, the karyotypes presented by Gomes-Júnior et al. (2016) occurs sympatrically on specimens collected in Amazonas, state of Brazil, whereas the karyotype reported by T. Lira (unpublished data) occurs in specimens collected in Pará, state of Brazil (Table 8, Fig. 12). We suggested a more detailed analyses, using morphological and molecular data combined, in the specimen studied by T. Lira, in order to correctly identify this specimen.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3211FFFB83E9FA44287FF8EE.taxon	description	The genus Oecomys comprises at least 18 recognized species, O. auyantepui (Tate 1939), O. bicolor (Tomes 1860), O. catherinae (Thomas 1909), O. cleberi (Locks 1981), O. concolor (Wagner 1845), O. flavicans (Thomas 1894), O. franciscorum (Pardiñas, Teta, Salazar-Bravo, Myers & Galliari 2016), O. mamorae (Thomas 1906), O. paricola (Thomas 1904), O. phaeotis (Thomas 1901), O. rex (Thomas 1910), O. roberti (Thomas 1904), O. rutilus (Anthony 1921), O. speciosus (Allen & Chapman 1893), O. superans (Thomas 1911), O. sydandersoni (Carleton, Emmons & Musser 2009), O. tapajinus (Thomas 1909), and O. trinitatis (Allen & Chapman 1893). These species were broadly distributed in lowland forested areas from Costa Rica southward to southern Bolivia and north-eastern Argentina (Musser & Carleton 2005; Carleton & Musser 2015; Pardiñas et al. 2016; Rocha et al. 2017; Suárez-Villota et al. 2017). All cytogenetic data available for the genus was presented on Table 8, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 12 and Fig. 13.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3210FFFA83E9FC4C2E12F852.taxon	description	Another karyotype was applied for this species by Gomes-Júnior et al. (2016). Karyotype: 2 n = 80 and FN = 142. Autosomal complement: nine metacentric pairs medium to small decreasing in size, five submetacentric pairs medium to small decreasing in size, 18 subtelocentric pairs (one large and the remaining medium to small decreasing in size), and seven acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large submetacentric (the largest chromosome of the complement); Y, a medium subtelocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, in the majority of metacentric and submetacentric the C-band extends to the short arm. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome presented the long arm entirely heterochromatic. G-banding was also performed. NORs were localized at the telomeric regions of the short arms of seven chromosomes of medium and small size. FISH with 18 S rDNA revealed signals at the telomeric regions of the short arms of 12 medium to small autosomal pairs, while FISH with 5 S rDNA revealed signals at the pericentromeric region of medium pair. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Gomes-Júnior et al. 2016). Two more karyotypes, with 2 n = 54 and FN = 82, and 2 n = 82 and FN = 116, were attributed to this species by Gomes-Júnior et al. (2016) (unpublished data from T. Lira), based on molecular data. However, these karyotypes were distinctly from those previously reported to this species. Thus, we suggested a more detailed analyses, using morphological and molecular data combined, in the specimens studied by T. Lira, in order to correctly identify these specimens. Finally, these variation in diploid and fundamental number of O. bicolor occurs in different localities of Amazon rainforest (Table 8, Fig. 12).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED320BFFE083E9FB7028FBFEDA.taxon	description	Karyotype: 2 n = 60 and FN = 62. Autosomal complement: one large subtelocentric pair, one small metacentric pair, and 27 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric or subtelocentric; Y, a medium acrocentric (Andrades-Miranda et al. 2001 b, pp. 272, Fig. 2 A; Andrade & Bonvicino 2003; Paresque et al. 2004; Langguth et al. 2005; Pinheiro & Geise 2008; Asfora et al. 2011; Malcher et al. 2017; SuárezVillota et al. 2017). Another fundamental number of 64 was reported due to the presence of one small metacentric pair instead of an acrocentric one (Pinheiro & Geise 2008; Asfora et al. 2011). A different diploid number of 62 was reported due to the presence of two acrocentric pairs instead of a large subtelocentric one (Malcher et al. 2017; Suárez-Villota et al. 2017). A diploid number of 61 was reported due to the presence of one heterochromatic acrocentric B chromosome (Andrades-Miranda et al. 2001 b). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes and at least two small acrocentric pairs presented C-band on the distal region of the long arm. The submetacentric X chromosome presented the short arm entirely heterochromatic and a C-band on the distal region of the long arm, the subtelocentric X chromosome vary from completely heterochromatic to presenting one C-band on the long arm. The Y chromosome was entirely heterochromatic (Andrades-Miranda et al. 2001 b; Langguth et al. 2005; Malcher et al. 2017; Suárez-Villota et al. 2017). G-banding was also performed (Langguth et al. 2005; Malcher et al. 2017). Multiple NORs, varying from four to seven were localized at the telomeric regions of the short arms of acrocentric chromosomes (Andrades-Miranda et al. 2001 b; Langguth et al. 2005). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed. Maps of chromosomal homology between O. catherinae with 2 n = 60 and 2 n = 62, using whole chromosome probes of H. megacephalus, was established. The comparative genomic mapping between these two O. catherinae specimens shows that these karyotypes differs from each other by the occurrence of fission-fusion and translocation rearrangements (Malcher et al. 2017). Another karyotype was reported by Suárez-Villota et al. (2017). Karyotype: 2 n = 54 and FN = 54. Autosomal complement: one small submetacentric pair, and 25 acrocentric pairs. Sex chromosomes: X, a large submetacentric; Y, a medium metacentric. C-banding was performed, the X chromosome presented the short arm entirely heterochrmatic and the Y chromosome was entirely heterochromatic. The variation in diploid and fundamental number of O. catherinae occurs widely distributed throughout the karyotyped specimens (Table 8, Fig. 13).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED320AFFE083E9FA9B2CD7F872.taxon	description	There were three different karyotypes for this species that occur in different localities (Table 8, Fig. 12). Karyotype 1: 2 n = 80 and FN = 140. Autosomal complement: 31 metacentric and submetacentric pairs, and eight acrocentric pairs. Sex chromosomes: X, a large submetacentric; Y, an acrocentric. C-banding was performed, the X chromosome presented the short arm entirely heterochrmatic and the Y chromosome was entirely heterochromatic (Suárez-Villota et al. 2017, pp. 12, Fig. 4 B). Karyotype 2: 2 n = 80 and FN = 134. Autosomal complement: 28 biarmed pairs, and 11 acrocentric pairs. Sex chromosomes: X, a large submetacentric; Y, a medium acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome presented an heterochromatic block on the distal region of the long arm (Suárez-Villota et al. 2017, pp. 12, Fig. 4 C). Karyotype 3: 2 n = 80 and FN = 124. Autosomal complement: one large subtelocentric pair, 22 biarmed pairs medium to small decreasing in size, and 16 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic. Multiple NORs, were localized at the telomeric regions of the short arms of 1 - 2 medium-small acrocentric pairs (Andrades-Miranda et al. 2001 b, pp. 272, Fig. 2 B).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3209FFE383E9FF502D93FE6A.taxon	description	Karyotype: 2 n = 60 and FN = 62. Autosomal complement: one large subtelocentric pair, one small metacentric pair, and 27 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium subtelocentric (Gardner & Patton 1976, pp. 12, Fig. 5 C). Baker et al. (1983) also reported a diploid number of 2 n = 58 and 2 n = 60 for O. concolor, and performed the G-banding of these karyotypes. The karyotype of O. concolor reported by Gardner & Patton (1976) was very similar to that presented for O. catherinae. However, systematic works of the genus (Gomes-Júnior et al. 2016; Suárez-Villota et al. 2017) recognized this karyotype as belonging to O. concolor.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3209FFE383E9FE1C2CE1FC9A.taxon	description	Pardiñas et al. (2016) recognized the karyotype described by Andrade & Bonvicino (2003) for an undescribed species of Oecomys from Corumbá, Mato Grosso do Sul state of Brazil, as O. franciscorum. Karyotype: 2 n = 72 and FN = 90. Autosomal complement: 10 biarmed pairs (one large and the remaining medium to small decreasing in size), and 25 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a submetacentric (the largest chromosome of the complement); Y, a medium submetacentric. One female presented heteromorphism of the short arm of the X chromosome. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of the autosome pairs. The X chromosome presented the short arm entirely heterochromatic, plus a C-band on the distal region of its long arm. The Y chromosome presented a heterochromatic block on the distal region of the long arm. G-banding was also performed (Andrade & Bonvicino 2003, pp. 198, Fig. 2 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3209FFE383E9FC4C29A8F9CE.taxon	description	Four different karyotypes were reported by Rosa et al. (2012) and Suárez-Villota et al. (2017), some of occurring sympatrically (Table 8, Fig. 13). Karyotype 1: 2 n = 70 and FN = 72. Autosomal complement: two medium to small bi-armed pairs, and 32 acrocentric pairs large to small decreasing in size (Rosa et al. 2012, pp. 271, Fig. 6). Karyotype 2: 2 n = 68 and FN = 72. Autosomal complement: three medium bi-armed pairs, and 30 acrocentric pairs large to small decreasing in size (Rosa et al. 2012, pp. 269, Fig. 2). Karyotype 3: 2 n = 70 and FN = 76. Autosomal complement: four biarmed pairs medium to small decreasing in size, and 30 acrocentric pairs large to small decreasing in size (Rosa et al. 2012, pp. 270, Fig. 4; Suárez-Villota et al. 2017). Karyotype 4: 2 n = 70 and FN = 74. Autosomal complement: three biarmed pairs medium to small decreasing in size, and 31 acrocentric pairs large to small decreasing in size (Suárez-Villota et al. 2017, pp. 12, Fig. 4 D). Sex chromosomes: X chromosome presented two different morphologies, a large subtelocentric, and a large submetacentric; Y, a small submetacentric or a biarmed chromosome. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome C-band vary from a heterochromatic block on the distal region of the short arm to present the short arm almost entirely heterochromatic. The Y chromosome was almost entirely or slightly heterochromatic (Rosa et al. 2012; Suárez-Villota et al. 2017). G-banding was also performed. The NORs stained vary from two to three acrocentric pairs of medium and / or small sized in the karyotypes 1 – 3, but were always localized at the telomeric regions of the short arms (Rosa et al. 2012). The differences in the diploid and fundamental number of the four karyotypes can be explained by rearrangements that include fusion / fission and pericentric inversions.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3209FFE383E9F9F029A8F9B1.taxon	description	Karyotype: 2 n = 62 and FN = 80, mentioned by Gomes-Júnior et al. (2016) (unpublished data from T. Lira).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3209FFE283E9F9642FBEFE6A.taxon	description	There were three different karyotypes from different localities (Table 8, Fig. 12). Karyotype 1: 2 n = 80 and FN = 114. Autosomal complement: 15 metacentric and submetacentric pairs medium to small decreasing in size, three subtelocentric pairs of medium-sized, and 21 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a very large submetacentric (the largest chromosome of the complement); Y, a very small acrocentric (Patton et al. 2000, pp. 130, Fig. 90). Karyotype 2: 2 n = 82 and FN = 106. Autosomal complement: 13 metacentric and submetacentric pairs medium to small decreasing in size, and 27 acrocentric pairs large to medium decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small acrocentric (Langguth et al. 2005, pp. 188, Fig. 2; Suárez-Villota et al. 2017). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochrmatic. The Y chromosome was slightly heterochromatic (Suárez-Villota et al. 2017). Karyotype 3: 2 n = 82 and FN = 110. Autosomal complement: 15 biarmed pairs medium to small decreasing in size, and 25 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic. Multiple NORs, were localized at the telomeric regions of the short arms of 1 – 2 medium to small acrocentric pairs (Andrades-Miranda et al. 2001 b, pp. 272, Fig. 2 C).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3208FFE283E9FE1C2E55FC9A.taxon	description	Karyotype: 2 n = 54 and FN = 90. Autosomal complement: 12 metacentric pairs large to small decreasing in size, three submetacentric pairs (two medium and one small), four subtelocentric pairs large to medium-sized, and seven acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium subtelocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin, ranging from subtle to conspicuous, on the pericentromeric region of some chromosomal pairs. G-banding was also performed. NORs were localized at the telomeric regions of the short arms of one large and one small autosomal pair. FISH with 18 S rDNA revealed signals at the telomeric regions of the short arms of one large and one small autosomal pair, while FISH with 5 S rDNA revealed signals at the pericentromeric region of one large autosomal pair. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Gomes-Júnior et al. 2016, pp. 412, Fig. 5).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3208FFE283E9FC4C2800FBB9.taxon	description	Karyotype: 2 n = 80 and FN = 108. Autosomal complement: one very large submetacentric pair, 11 metacentric and submetacentric pairs medium to small decreasing in size, three subtelocentric pairs (one large and two medium), and 24 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a medium submetacentric; Y chromosome presented two different morphologies, a small metacentric, and a small acrocentric (Gardner & Patton 1976, pp. 12, Fig. 5 B; Patton et al. 2000; Andrade & Bonvicino 2003). According to Patton et al. (2000), this karyotype was erroneously attributed to O. concolor by Gardner & Patton (1976).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3208FFED83E9F92C28A0FDA6.taxon	description	Karyotype: 2 n = 54 and FN = 84. Autosomal complement: 16 biarmed pairs large to small decreasing in size, and 10 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a medium submetacentric (Fig. 14 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. One medium submetacentric pair presented a pericentromeric heterochromatin block that extend to the short arm and one small acrocentric pair presented an interstitial C-band on its long arm. The X chromosome presented a conspicuous pericentromeric heterochromatic block and an interstitial lightly stained C-band on its long arm. The Y chromosome was almost entirely heterochromatic (Fig. 14 B). Gbanding was performed to allow the correct identification of all homologous pairs (Fig. 14 C). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Fig. 14 D). We compare the karyotype of Oecomys sp. 1 (2 n = 54, FN = 84) with O. rutilus (2 n = 54, FN = 90) from Rio Negro, Amazonas state of Brazil. These two complements differ mainly by the presence of three medium to small acrocentric pairs in Oecomys sp. 1, instead of three biarm pairs in O. rutilus, and by the morphology of X chromosome. Also, the karyotype of Oecomys sp. 1 presents more conspicuous heterochromatic C-band than O. rutilus. The G-band patterns between the two karyotype were equally distinct. Based on these comparative analyses, we suggested that the species mentioned here as Oecomys sp. 1 was distinctly from O. rutilus. In addition, the same diploid and fundamental number of Oecomys sp. 1 was mentioned by Gomes-Júnior et al. (2016) (unpublished data from T. Lira). However, as these authors provided no additional information, a more thorough comparison was not possible. Nevertheless, as the karyotype mentioned by Gomes-Júnior et al. (2016) were from populations from Rio Cuieiras, Amazonas state of Brazil, it was likely that they may belong to the same species.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3208FFE283E9FB6C2F19F97A.taxon	description	The karyotype of an undescribed species was reported by Patton et al. (2000, pp. 128, Fig. 88). Karyotype: 2 n = 86 and FN = 98. Autosomal complement: seven small metacentric and submetacentric pairs, and 35 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large subtelocentric; Y, unknown as only females was analyzed. Two additional karyotypes attributed to a presumptive new species of Oecomys, with 2 n = 54, FN = 84 and 2 n = 54, FN = 86, were presented by Gomes-Júnior et al. (2016; unpublished data from T. Lira) for populations from Amazonas, Brazil. Based on our sampling efforts, we present three different karyotypes for the genus, mentioned here as Oecomys sp. 1, Oecomys sp. 2 and Oecomys sp. 3. The cytogenetic analyzes were performed for specimens collected in the Rio Japurá and Rio Içá, Amazonas state of Brazil (Table 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3207FFEC83E9F88A2E73FDFA.taxon	description	Karyotype: 2 n = 64 and FN = 92. Autosomal complement: 15 biarmed pairs large to small decreasing in size, and 16 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a large subtelocentric; Y, a medium acrocentric (Fig. 15 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic (Fig. 15 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 15 C). FISH with telomeric sequences revealed signals at the ends of all chromosome arms, and additional telomeric sequences was found on the pericentromeric region of one medium submetacentric pair (Fig. 15 D). We compare the karyotype of Oecomys sp. 2 (2 n = 64, FN = 92) with O. auyantepui (2 n = 64, FN = 110) from Rio Jatapú, Amazonas state of Brazil. These two complements were distinct mainly by the presence of nine acrocentric pairs in Oecomys sp. 2, instead of nine biarm pairs in O. auyantepui, and by the morphology of sex chromosome. Also, the karyotype of Oecomys sp. 2 presents more conspicuous heterochromatic C-band than O. auyantepui. The G-band patterns between the two karyotypes were equally distinct. In addition, Oecomys sp. 2 presented an interstitial telomeric sequence on the pericentromeric region of one medium submetacentric pair, while O. auyantepui presented an interstitial telomeric sequence on the centromeric region of the X chromosome. Based on these comparative analyses, we suggested that the species mentioned here as Oecomys sp. 2 was distinctly from O. auyantepui.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3205FFEF83E9FF502D85FB2A.taxon	description	Karyotype: 2 n = 84 and FN = 110. Autosomal complement: 14 biarmed pairs medium to small decreasing in size, and 27 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a very large submetacentric (the largest chromosome of the complement); Y, a large subtelocentric (Fig. 16). Due to the poor quality of chromosome preparation, was not possible to analyzed this karyotype by banding or FISH, however the C-banding pattern of sex chromosomes was presented in the inset of Fig. 16. The X chromosome presented the long arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic. We compare the karyotype of Oecomys sp. 3 (2 n = 84, FN = 110) with others Oecomys species that presents similar diploid number. The chromosome complement of O. bicolor (2 n = 80, FN = 140), described by Patton et al. (2000) for samples from Rio Juruá, Acre and Amazonas states of Brazil, showed a slight similarity with Oecomys sp. 3. However, only the conventional staining was available to compare these karyotypes. Thus, a more detailed analyses of Oecomys sp. 3, using morphological and molecular approaches, was necessary to identify this specimen. The genus Oecomys was the second most specious of tribe Oryzomyini, and the cytogenetic data reinforce such diversity. A total of 13 different diploid number, varying from 54 to 86, and 25 different fundamental numbers, varying from 54 to 142, were reported. These species exhibit autosomal and sex chromosome polymorphisms, in addition to the presence of B chromosomes. Also, there was no cytogenetic information for six species of the genus, and other six karyotypes were described as unnamed species. Based on such diversity was evident that a wide review of the genus was necessary.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3205FFEF83E9FAF92E69F87A.taxon	description	The genus Oligoryzomys, the most diverse of tribe Oryzomyini, comprises 25 extant species, namely, O. andinus (Osgood 1914), O. arenalis (Thomas 1913), O. brendae (Massoia 1998), O. chacoensis (Myers & Carleton 1981), O. costaricensis (Allen 1893), O. delicatus (Allen & Chapman 1897), O. destructor (Tschudi 1844) (that includes O. d. destructor and O. d. spodiurus (Hershkovitz 1940 )), O. flavescens (Waterhouse 1837), O. fornesi (Massoia 1973), O. fulvescens (Saussure 1860), O. griseolus (Osgood 1912), O. longicaudatus (Bennett 1832), O. magellanicus (Bennett 1836), O. mattogrossae (Allen 1916), O. messorius (Thomas 1901), O. microtis (Allen 1916), O. moojeni (Weksler & Bonvicino 2005), O. nigripes (Olfers 1818), O. pachecoi (Hurtado & D’Elía 2018), O. rupestris (Weksler & Bonvicino 2005), O. stramineus (Bonvicino & Weksler 1998), O. utiaritensis (Allen 1916), O. vegetus (Bangs 1902), O. victus (Thomas 1898), and O. yatesi (Palma & Rodríguez-Serrano 2017). The genus was distributed from northern Central America to the southernmost part of South America, inhabiting environments like rain forest (Amazonian and Atlantic Forests), open and dry areas (Cerrado, Caatinga and Restinga) and flooding-prone areas (Pampas and Pantanal) (Prado & Percequillo 2013; Weksler & Bonvicino 2015 b; Hurtado & D’Elía 2019 a). Due to the high number of recognized species for this genus, we based our cytogenetic review on the last review of the genus performed by Weksler & Bonvicino (2015 b). All cytogenetic data available for the genus was presented on Table 9, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 17, Fig. 18 and Fig. 19.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3204FFEE83E9FB73284EFAFD.taxon	description	Karyotype: 2 n = 60 and FN = 70. Autosomal complement: six metacentric and submetacentric pairs (two large, one medium and three small), and 23 acrocentric pairs (one large and the remaining small). Sex chromosomes: X was a large acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 8, Fig. 3 E).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3204FFEE83E9FAAF2D7DF9D5.taxon	description	Karyotype: 2 n = 58 and FN = 74. Autosomal complement: nine metacentric and submetacentric pairs (two large and remaining small), and 19 acrocentric pairs (one large and the remaining small). Sex chromosomes: X, a medium submetacentric; Y, a small acrocentric. G-banding was also performed (Espinosa & Reig 1991, pp. 311, Fig. 3 A; Teta et al. 2013).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3204FFEE83E9F9872E5EF8C9.taxon	description	The karyotypes of O. brendae and O. chacoensis were morphological different, despite the fact that they share the same diploid and fundamental number.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3204FFE983E9F8FB2822FE4E.taxon	description	Karyotype: 2 n = 60 and FN = 72. Autosomal complement: seven metacentric and submetacentric pairs medium to small decreasing in size, and 22 acrocentric pairs (three large and the remaining small). Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric (Kiblisky 1969, pp. 1339, Fig. 3). Another karyotype with a different diploid and fundamental number was reported by Gardner & Patton (1976), 2 n = 62 and FN = 74 or 76 (fundamental number comprises autosomal and sex chromosomes). Chromosome complement: five metacentric pairs (one large and four small), three subtelocentric pairs large to small decreasing in size, and 23 acrocentric pairs (one very large and the remaining small), the sex chromosome of this karyotype was unknown as only a female was examined. Baker et al. (1983) reported a diploid number of 60 and 64 for O. delicatus, and presented the G-banding for these karyotypes. These variation in diploid and fundamental number of O. delicatus occurs in different localities of Suriname and Venezuela (Table 9). This karyotype was originally attributed to O. longicaudatus, variant 3, by Gardner & Patton (1976), but Weksler & Bonvicino (2015 b) assigned it to O. delicatus.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3203FFE983E9FA67291BF970.taxon	description	Karyotype: 2 n = 60 and FN = 76. Autosomal complement: nine metacentric and submetacentric pairs (two large and seven medium to small), and 20 acrocentric pairs (one large and the remaining small). Sex chromosomes: X, a large submetacentric; Y, a medium metacentric (Gardner & Patton 1976, pp. 8, Fig. 3 D). This karyotype was referred as belonging to O. destructor by Weksler & Bonvicino (2015 b). However, according to Hurtado & D’Elía (2019 b), the authors taken these values arbitrary from Gardner & Patton (1976), whom described at least three karyotypes for specimens from localities in the current known distribution of O. destructor. Consequently, such specimens should be revised in order to confirm the karyotype of this species (Hurtado & D’Elía 2019 b).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3203FFE883E9F9232D83FCD2.taxon	description	Karyotype: 2 n = 64 and FN = 66. Autosomal complement: two small metacentric and submetacentric pairs, and 29 acrocentric pairs (one very large and the remaining large to small decreasing in size). Sex chromosomes: X, a large submetacentric that presented a variable centromeric index; Y chromosome presented three different morphologies, a medium metacentric, a medium submetacentric, and a small acrocentric (Yonenaga et al. 1976; Myer & Carleton 1981, pp. 16, Fig. 5 C; Brum-Zorrilla et al. 1988; Rioja et al. 1988; Espinosa & Reig 1991; Sbalqueiro et al. 1991; Aniskin & Volobouev 1999; Andrades-Miranda et al. 2001 a; Weksler & Bonvicino 2005; Di-Nizo et al. 2015). A different diploid number from 65 to 68 were reported due to the presence of 1 to 4 small acrocentric or metacentric supernumerary chromosomes, mosaicism karyotypes with 2 n = 64 / 64 + 1 B and 2 n = 64 + 1 B / 64 + 2 Bs were also reported. These variations in number and presence of supernumerary chromosomes were widely distributed throughout the karyotyped specimens (Table 9, Fig. 19; see Yonenaga et al. 1976; Myer & Carleton 1981; Brum-Zorrilla et al. 1988; Rioja et al. 1988; Espinosa & Reig 1991; Sbalqueiro et al. 1991; Aniskin & Volobouev 1999; Andrades-Miranda et al. 2001 a; Weksler & Bonvicino 2005; Di-Nizo et al. 2015). Additional chromosome polymorphisms, reported only for samples from Minas Gerais, state of Brazil, were due to a whole heterochromatic arm occurring in 1 to 3 large to medium-sized acrocentric chromosomes, and a fundamental number of 68 possibly due to a pericentric inversion affecting one small autosomal pair (Yonenaga et al. 1976; Brum-Zorrilla et al. 1988; Rioja et al. 1988; Espinosa & Reig 1991; Bonvicino & Weksler 1998; Aniskin & Volobouev 1999; Sbalqueiro et al. 1991; Weksler & Bonvicino 2005). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome has a heterochromatic short arm, which was responsible for the observed variable centromeric indexes. The metacentric or submetacentric Y chromosomes presented over half their short arm heterochromatic, while the acrocentric Y chromosome was entirely heterochromatic. The B chromosomes were entirely C-positive, but the staining was less intense in some cases (Rioja et al. 1988; Espinosa & Reig 1991; Sbalqueiro et al. 1991; Aniskin & Volobouev 1999). G-banding was also performed (Brum-Zorrilla et al. 1988; Espinosa & Reig 1991; Sbalqueiro et al. 1991; Aniskin & Volobouev 1999; Di-Nizo et al. 2015). Multiple NORs, varying from two to eight were localized at the telomeric regions of the short arms of small acrocentric pairs (Sbalqueiro et al. 1991).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3202FFE883E9FC842FE2FC2A.taxon	description	Karyotype: 2 n = 60 and FN = 74. Autosomal complement: six metacentric and submetacentric pairs (two large, two medium, and two small), three large subtelocentric pairs, and 21 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X chromosome presented two different morphologies, a large subtelocentric, and a large acrocentric; Y, a small acrocentric (Haiduk et al. 1979, pp. 611, Fig. 2 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3276FF9C83E9FF5028A7FE16.taxon	description	Karyotype: 2 n = 56 and FN = 66. Autosomal complement: six small metacentric and submetacentric pairs, and 21 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X chromosome presented two different morphologies, a medium submetacentric, and a medium subtelocentric; Y chromosome presented two different morphologies, a small submetacentric, and a small subtelocentric (Gallardo & González 1977, pp. 313, Fig. 1 A; Gallardo & Patterson 1985; Espinosa & Reig 1991; Palma et al. 2005; Belmar-Lucero et al. 2009; Palma & Rodríguez-Serrano 2017). Espinosa & Reig (1991) also reported a different fundamental number of 64 for a sample from Rio Negro, state of Argentina, according to the authors this difference was probably due to a pericentric inversion involving an autosomal pair. G-banding was also performed.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3276FF9C83E9FE3828DCFD42.taxon	description	Karyotype: 2 n = 54 and FN = 66. Autosomal complement: seven metacentric and submetacentric pairs (one very large and the remaining small), and 19 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium submetacentric; Y, a small submetacentric (Gallardo & Patterson 1985, pp. 53, Fig. 2).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3276FF9C83E9FD742E92FB02.taxon	description	Karyotype: 2 n = 62 and FN = 64. Autosomal complement: two biarmed pairs medium to small size, and 28 acrocentric pairs (one very large and the remaining large to small decreasing in size). Sex chromosomes: X chromosome presented two different morphologies, a large subtelocentric, and a large acrocentric; Y, a small acrocentric (Myer & Carleton 1981; Bonvicino & Weksler 1998; Andrades-Miranda et al. 2001 a, pp. 1084, Fig. 2 B; Weksler & Bonvicino 2005; Pereira & Geise 2007; Di-Nizo et al. 2015; Weksler et al. 2017). A different fundamental number of 66 was reported due to the presence of one small metacentric pair instead of an acrocentric one, moreover, this karyotype also presented a submetacentric Y chromosome (Andrades-Miranda et al. 2001 a). This variation in fundamental number occurs sympatrically on specimens collected in Goiás, state of Brazil (Table 9, Fig. 17). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, with the exception of the large acrocentric pair. The X chromosome presented pericentromeric heterochromatic blocks varied in size. The Y chromosome was entirely heterochromatic (Andrades-Miranda et al. 2001 a). G-banding was also performed (Di-Nizo et al. 2015). Multiple NORs, were localized on the short arms of one to three pairs. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Andrades-Miranda et al. 2001 a).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3276FF9C83E9FB342F35F9CE.taxon	description	Karyotype: 2 n = 66 and FN = 74. Autosomal complement: five metacentric and submetacentric pairs medium to small decreasing in size, and 27 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, with the exception of the large acrocentric pair. The X chromosome presented pericentromeric heterochromatic blocks. The Y chromosome was entirely heterochromatic. Multiple NORs, were localized at the telomeric regions of the short arms of two autosomes pairs (Andrades-Miranda et al. 2001 a, pp. 1084, Fig. 2 C).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3276FF9C83E9F9F02F0EF87E.taxon	description	Karyotype: 2 n = 64 and FN = 66. Autosomal complement: one large submetacentric pair, one small metacentric pair, and 29 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium subtelocentric; Y chromosome presented two different morphologies, a small metacentric, and a small acrocentric (Gardner & Patton 1976, pp. 8, Fig. 3 B; Aniskin & Volobouev 1999; Patton et al. 2000). Another fundamental number of 64 was reported for a sample from Mato Grosso, state of Brazil, due to the presence of one large acrocentric pair instead of a submetacentric one (Di-Nizo et al. 2015). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the autosomal pairs, with the exception of one the large submetacentric pair and five acrocentric pairs of medium-sized. The X chromosome presented the short arm entirely heterochromatic. The metacentric Y chromosome was entirely heterochromatic (Aniskin & Volobouev 1999). G-banding was also performed (Aniskin & Volobouev 1999; Di-Nizo et al. 2015).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3275FF9F83E9FF502851FBF2.taxon	description	Karyotype: 2 n = 70 and FN = 74. Autosomal complement: three small metacentric and submetacentric pairs, and 31 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X chromosome presented two different morphologies, a large submetacentric, and a large subtelocentric; Y chromosome presented two different morphologies, a medium subtelocentric, and a small acrocentric (Andrades-Miranda et al. 2001 a, pp. 1088, Fig. 4; Lima et al. 2003; Bonvicino et al. 2005; Weksler & Bonvicino 2005; Agrellos et al. 2012; Di-Nizo et al. 2015). Variation in fundamental number, with 72 and 76, was reported due to a pericentric inversion affecting one medium and one small autosomal pair (Lima et al. 2003; Di-Nizo et al. 2015). These variation in fundamental number occurs sympatrically on specimens collected in Goiás (FN = 72 and FN = 74) and Tocantins (FN = 74 and FN = 76), states of Brazil (Table 9, Fig. 17). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of almost all autosomal pairs. The X chromosome C-band encompasses from the pericentromeric region to the short arm almost entirely heterochromatic. The medium subtelocentric Y chromosome was entirely heterochromatic (Andrades-Miranda et al. 2001 a; Lima et al. 2003). G-banding was also performed (Andrades-Miranda et al. 2001 a; Lima et al. 2003; Di-Nizo et al. 2015). Multiple NORs, varying from three to ten were localized at the telomeric regions of the short arms on acrocentric pairs from large to small size (Andrades-Miranda et al. 2001 a; Lima et al. 2003). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Andrades-Miranda et al. 2001 a). Whole chromosome probes of O. moojeni was made by flow cytometry, from sorted chromosomes of fibroblast cell culture. These probes were used to established maps of chromosomal homology between five Oligoryzomys species (O. fornesi, O. microtis, O. moojeni, O. nigripes and O. rupestris). The results showed extensive chromosomal rearrangement, such as pericentric inversions or repositioning of centromeres, Robertsonian rearrangements and tandem fusions / fissions, as well as gain / activation or loss / inactivation of centromeres and telomeric sequences have driven the huge genome reshuffling in these closely related species (Di-Nizo et al. 2015). In order to infer the chromosomal rearrangements directions that occurred during the karyotype evolution of Oligoryzomys, the authors compare these results of chromosome painting with a molecular phylogeny of the genus and concluded that chromosomal evolution of these species were associated with both, decrease and increase of diploid number.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3275FF9F83E9FBA42952F8EE.taxon	description	Karyotype: 2 n = 62 and FN = 82. Autosomal complement: one large subtelocentric pair, 10 metacentric and submetacentric pairs large to small decreasing in size, and 19 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X chromosome presented three different morphologies, a large metacentric, a large submetacentric, and a large subtelocentric; Y chromosome presented four different morphologies, a medium metacentric, a medium submetacentric, a small submetacentric, and a small subtelocentric. Different diploid numbers of 60 and 61 and fundamental number of 76 and 78 to 81 was reported due to pericentric inversions in four autosomal pairs (Yonenaga et al. 1976; Myer & Carleton 1981, pp. 16, Fig. 5 A; Brum-Zorrilla et al. 1988; Almeida & YonenagaYassuda 1991; Espinosa & Reig 1991; Bonvicino & Weksler 1998; Andrades-Miranda et al. 2001 a; Bonvicino et al. 2001; Paresque et al. 2004; Weksler & Bonvicino 2005; Paresque et al. 2007; Pereira & Geise 2007; Moreira et al. 2009; Agrellos et al. 2012; Di-Nizo et al. 2014; Di-Nizo et al. 2015; Gatto-Almeida et al. 2016). Such variation in diploid and fundamental number occurs widely distributed throughout the karyotyped specimens (Table 9, Fig. 18). A diploid number of 61 was reported due to a monosomy of the X chromosome (Andrades-Miranda et al. 2001 a; Paresque et al. 2007). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. In some metaphases, three pairs of autosomes presented vestiges of telomeric heterochromatin. One arm of the metacentric X chromosome and the short arm of the submetacentric X was entirely heterochromatic. The Y chromosome was entirely heterochromatic (Almeida & Yonenaga-Yassuda 1991; Andrades-Miranda et al. 2001 a). The G- and R-banding were also performed (Almeida & Yonenaga-Yassuda 1991; Espinosa & Reig 1991; Bonvicino et al. 2001; Di-Nizo et al. 2015). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Paresque et al. 2007).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3275FF9E83E9F8902CCBFD42.taxon	description	Karyotype: 2 n = 46 and FN = 52. Autosomal complement: one small metacentric pair, one small submetacentric pair, two very large subtelocentric pairs, and 18 acrocentric pairs (one very large and 17 small). Sex chromosomes: X chromosome presented three different morphologies, a medium submetacentric, a medium subtelocentric, and a medium acrocentric; Y, a small acrocentric (Silva & Yonenaga-Yassuda 1997; pp. 218, Fig. 2; Bonvicino et al. 2005; Weksler & Bonvicino 2005; Pereira & Geise 2007; Di-Nizo et al. 2015). Silva & Yonenaga-Yassuda (1997) reported another diploid number of 44 due to a centric fusion of the large acrocentric pair with one small acrocentric pair, and a mosaicism with 2 n = 44 / 45 and FN = 52 / 53 due to the presence of a small acrocentric chromosome. These variations in diploid and fundamental number were reported only for specimens collected in Minas Gerais, state of Brazil (Table 9, Fig. 17). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes, with the exception of the subtelocentric pairs. The subtelocentric X presented a proximal heterochromatic block that extended to the short arm, the acrocentric X chromosome presented a large heterochromatic block on the proximal region and an interstitial lightly stained C-band on its long arm. The Y chromosome was entirely heterochromatic (Silva & Yonenaga-Yassuda 1997). The G- and R-banding were also performed (Silva & Yonenaga-Yassuda 1997; Di-Nizo et al. 2015). Multiple NORs, varying from two to twelve were localized at the telomeric regions of the short arms of acrocentric autosomes. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Silva & Yonenaga-Yassuda 1997).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3274FF9E83E9F89028D5F81A.taxon	description	Karyotype: 2 n = 68 and FN = 74 or 76. Chromosome complement: one large subtelocentric pair, four metacentric and submetacentric pairs of small sized, and 29 acrocentric pairs large to small decreasing in size. The sex chromosome was unknown as only a female was examined (Gardner & Patton 1976, pp. 8, Fig. 3 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3274FF9E83E9FD7428F6FB9E.taxon	description	Karyotype: 2 n = 52 and FN = 68. Autosomal complement: nine metacentric pairs (two large, five medium, and two small), and 16 acrocentric pairs (one large and the remaining medium to small decreasing in size). Sex chromosomes: X, a large submetacentric; Y, a medium metacentric (Maia et al. 1983; Bonvicino & Weksler 1998, pp. 94, Fig. 2; Andrades-Miranda et al. 2001 a; Weksler & Bonvicino 2005; Geise et al. 2010; Fernandes et al. 2012). Another fundamental number of 69 was reported due to a pericentric inversion in one chromosome of a small acrocentric pair (Bonvicino & Weksler 1998), and these authors mentioned a fundamental number of 70 apparently due to an inversion in a small acrocentric pair (unpublished data from A. L. Gardner mentioned by Bonvicino & Weksler 1998). These variation in fundamental number occurs on specimens collected in Minas Gerais and Pernambuco, states of Brazil (Table 9, Fig. 17). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of the autosomes, but were absent in one large metacentric and on the X chromosome. The Y chromosome was entirely heterochromatic (Andrades-Miranda et al. 2001 a).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3274FF9E83E9FB402843FACA.taxon	description	Karyotype: 2 n = 72 and FN = 76. Autosomal complement: three small metacentric and submetacentric pairs, and 32 acrocentric pairs (three large and the remaining medium to small decreasing in size). Sex chromosomes: X, a large submetacentric; Y, a small submetacentric (Agrellos et al. 2012, pp. 9, Fig. 5 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3274FF9E83E9FAFC2D15F9CE.taxon	description	According to the Rogers et al. (2009), the karyotype reported by Gardner & Patton (1976) for O. fulvescens from Costa Rica actually represents O. vegetus. Karyotype: 2 n = 54 and FN = 68. Autosomal complement: five metacentric and submetacentric pairs (one large and four medium to small), three large subtelocentric pairs, and 18 small acrocentric pairs. Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 8, Fig. 3 F).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3274FF9E83E9F9F02D51F8EE.taxon	description	Karyotype: 2 n = 54 and FN = 66. Autosomal complement: seven biarmed pairs (one very large and the remaining small), and 19 acrocentric pairs decreasing in size. Sex chromosomes: X and Y were subtelocentrics (Palma & Rodríguez-Serrano 2017, pp. 6, Fig. 2 A). According to the authors, this karyotype was very similar with the karyotype of O. magellanicus reported by Gallardo & Peterson (1985). The karyotype of two more undescribed species were reported by Gardner & Patton (1976) and Andrades-Miranda et al. (2001 a).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3273FF9983E9FF502DA5FDA6.taxon	description	The genus Oligoryzomys exhibits 15 different diploid numbers, varying from 44 to 72, and 16 different fundamental numbers, varying from 52 to 82, one of the widest cytogenetic variations within the tribe. These species also present autosomal and sex chromosome polymorphisms, in addition to the presence of B chromosomes. Presently, there was no cytogenetic information for six known species of the genus, and two karyotypes were described for still unnamed species.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3273FF9983E9FD742E72FC62.taxon	description	The genus Oryzomys, that until recently was the most speciose of the tribe Oryzomyini, now comprises five species, O. antillarum (Thomas 1898), O. couesi (Alston 1877), O. dimidiatus (Thomas 1905), O. gorgasi (Hershkovitz 1971), and O. palustris (Harlan 1837). These species range from North and Central America to northwestern South America (Percequillo 2015 f; Voss & Weksler 2009; Weksler et al. 2006). There was cytogenetic information available only for O. couesi and O. palustris.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3273FF9983E9FC14291CFB66.taxon	description	Karyotype: 2 n = 56 and FN = 56. Autosomal complement: one small metacentric pair, and 26 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium subtelocentric (Benson & Gehlbach 1979, pp. 227, Fig. 1 A; Haiduk et al. 1979). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented a pericentromeric heterochromatic blocks (Haiduk et al. 1979). G-banding karyotype was performed by Baker et al. (1983).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3273FF9983E9FB082EDDFA22.taxon	description	The karyotypes of O. couesi and O. palustris were very similar, but O. palustris exhibits a distinctly large acrocentric chromosome that was not present in O. couesi.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3273FF9883E9F9F12FDBFE4E.taxon	description	Monotypic genus represented by P. simplex (Winge 1887), whose distribution ranges from north-eastern Argentina, western Paraguay to eastern Bolivia, and from there eastward through Brazil and far in the north-eastern portion of this latter country (Prado & Percequillo 2013; Voss & Myers 1991). Karyotype: 2 n = 56 and FN = 54. Autosomal complement: 27 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a medium acrocentric (Voss & Myers 1991; Oliveira & Langguth 2004; Bonvicino et al. 2005; Moreira et al. 2013, pp. 203, Fig. 2). An autosomal heteromorphism leading to FN = 55 was reported due to the presence of a whole heterochromatic arm in one chromosome of medium-sized with one metacentric and one acrocentric element. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. On the heteromorphic pair, the metacentric element exhibited one entirely heterochromatic arm. The X chromosome presented pericentromeric heterochromatic blocks and an interstitial lightly stained C-band on its long arm. The Y chromosome presented two conspicuous interstitial heterochromatic bands on its long arm, in addition to the pericentromeric heterochromatin. G-banding was also performed. Multiple NORs, varying from five to eight were localized at the telomeric regions of the short arms of small autosomes. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed. FISH with whole chromosome X of Holochilus sciureus (HSC) evidenced that HSC X hybridized on the whole X chromosome of P. simplex, but also hybridized to the pericentromeric region of the Y chromosome and produced a weak interstitial signal on its long arm (Moreira et al. 2013).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3272FF9883E9FB082DFCF95E.taxon	description	Karyotype: 2 n = 62 and FN = 80. Autosomal complement: one large subtelocentric pair, nine metacentric and submetacentric pairs medium to small decreasing in size, and 20 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a submetacentric (the largest chromosome of the complement); Y, a large subtelocentric (Fig. 20 A). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented an interstitial C-band on the short arm, a pericentromeric heterochromatic block and a conspicuous interstitial C-band on its long arm. The Y chromosome was almost entirely heterochromatic (Fig. 20 B). G-banding was performed to allow the correct identification of all homologous pairs (Fig. 20 C). FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed (Fig. 20 D). This karyotype was basically the same reported by Patton & Silva (1995) for S. melanops with the presence of one additional acrocentric pair. Based only on the cytogenetic data these specimens seem to belongs to S. melanops and the difference in karyotype could have resulted from a fission-fusion involving an autosomal pair.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3272FF9883E9FE1D2E0BFD6E.taxon	description	The genus Scolomys comprises two species, S. melanops (Anthony 1924) and S. ucayalensis (Pacheco 1991) (that includes S. juruaense (Patton & Silva 1995 )) (Gómez-Laverde et al. 2004). S. melanops inhabits the eastern slopes of the Andes of Ecuador and Peru, and S. ucayalensis occurs in southern Colombia, north-eastern Peru, and western Brazil (Prado & Percequillo 2013).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3272FF9883E9FD102E93FC46.taxon	description	Karyotype: 2 n = 60 and FN = 78. Autosomal complement: one large subtelocentric pair, nine metacentric and submetacentric pairs medium to minute decreasing in size, and 19 acrocentric pairs medium to small decreasing in size. Sex chromosomes: X, a submetacentric (the largest chromosome of the complement); Y, a large subtelocentric element (Patton & Silva 1995, pp. 331, Fig. 7 B).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3272FF9883E9FC682FB3FB66.taxon	description	We presented another karyotype for the genus, mentioned here as Scolomys sp., obtained from fifteen males collected on the Rio Içá and Rio Japurá, Amazonas, Brazil (Table 1).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3272FF9883E9F9182CE1F830.taxon	description	Monotypic genus represented by S. alfari (Allen 1897), found throughout trans-Andean lowland and lower montane forests in Colombia, Venezuela, and Ecuador, besides Central American lowland forests from Panamá to Honduras (Pine et al. 2012; Prado & Percequillo 2013; Weksler 2015 b). Karyotype: 2 n = 56 and FN = 54. Autosomal complement: 27 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large-medium acrocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 13, Fig. 6 A).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3271FF9A83E9F98C2D90FEA2.taxon	description	Monotypic genus represented by S. angouya (Fischer 1814), that occur in the Brazilian Atlantic Forest, from Espírito Santo to Rio Grande Sul; in the Argentinean Atlantic Forest (Misiones) and Semideciduous forests (Corrientes, Entre Ríos, Formosa); and in the Paraguayan Atlantic Forest, both on left and right bank of Río Paraguay (Weksler et al. 2006; Chiquito et al. 2014). Karyotype: 2 n = 58 and FN = 60. Autosomal complement: two small metacentric pairs, and 26 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric (Andrades-Miranda et al. 2000, pp. 465, Fig. 2 A; Silva & Yonenaga-Yassuda 2004; Di-Nizo et al. 2014). The autosomal heteromorphism leading to 2 n = 57 was reported due to a Robertsonian rearrangement involving two acrocentric autosomes in heterozygous condition. Another karyotype was reported with 2 n = 60 due to a facultative presence of two small metacentric B chromosomes, these chromosomes were slightly heteromorphic in size, heterochromatic, G-positive although less intensely stained than the darker bands and NOR carrier at the ends of both arms (Silva & Yonenaga-Yassuda 2004). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented pericentromeric heterochromatic blocks. The Y chromosome was entirely heterochromatic (Andrades-Miranda et al. 2000). G-banding was also performed. Multiple NORs were localized at the telomeric regions of the short arms of small autosomes (Andrades-Miranda et al. 2000; Silva & Yonenaga-Yassuda 2004).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3270FF9A83E9FD10290BFC9A.taxon	description	Karyotype: 2 n = 58 and FN = 80. Autosomal complement: nine large to medium metacentric and submetacentric pairs, two very small metacentric pairs, one large subtelocentric pair, and 16 small acrocentric pairs. Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric (Gardner & Patton 1976, pp. 6, Fig. 2 E).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3270FF9A83E9FE712FE4FD6E.taxon	description	The genus Transandinomys comprises two species, T. bolivaris (Allen 1901), and T. talamacae (Allen 1891). Both occur in tropical lowland and premontane trans-Andean rain forests from north-eastern Nicaragua throughout much of Costa Rica and Panama to Colombia, western Ecuador, and northern Venezuela (Musser et al. 1998; Weksler et al. 2006). All cytogenetic data available for the genus was presented on Table 10. The distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 21.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED3270FF8583E9FC4C2825FC46.taxon	description	Karyotype 1: 2 n = 34 and FN = 64. Autosomal complement: two large submetacentric pairs, one large subtelocentric pair, and 13 metacentric and submetacentric pairs medium to small decreasing in size. Sex chromosomes: X, a medium acrocentric; Y, a small subtelocentric. A secondary constriction was observed at the long arm of one large submetacentric pair, and in two small metacentric pairs (Perez-Zapata et al. 1986, pp. 371, Fig. 2; Musser et al. 1998). This karyotype was reported for samples from Aragua, Delta Amacuro and Yaracuy, states of Venezuela (Table 10, Fig. 21). Karyotype 2: The diploid numbers ranges from 40 to 42, and were reported a different chromosomal set in each one of the four animals karyotyped for samples from Zulia, state of Venezuela (Table 10, Fig. 21) (Musser et al. 1998, pp. 159, Fig. 69): (i) sample (male) 2 n = 40 and FN = 66 or 67 (fundamental number comprises autosomal and sex chromosomes). Chromosomal complement: ten large to small metacentric and submetacentric pairs decreasing in size, four subtelocentric pairs (two large and two medium), four acrocentric pairs (two large and two small), and four unpaired elements that include one medium metacentric, one small and another very small acrocentric, and the medium acrocentric X chromosome, which has very short arm. The Y chromosome was one of the first three unpaired elements (Musser et al. 1998); (ii) sample (male) 2 n = 41 and FN = 63 or 64 (fundamental number comprises autosomal and sex chromosomes). Chromosomal complement: nine medium to small metacentric and submetacentric pairs decreasing in size, three subtelocentric pairs (two large and one medium), seven acrocentric pairs (two large and five medium to small), and three unpaired elements that include a small metacentric, a small acrocentric (one of which probably represents the Y chromosome), and the medium-sized acrocentric X chromosome with a very short arm (Musser et al. 1998); (iii) sample (female) 2 n = 41 and FN = 66. Autosomal complement: nine medium to small metacentric and submetacentric pairs decreasing in size, three subtelocentric pairs (two large and one medium), six acrocentric pairs (two large and four medium to small), and three unpaired elements that include a medium submetacentric, a small metacentric, and a medium subtelocentric. Sex chromosomes: X, a medium acrocentric with a very short arm (Musser et al. 1998). (iv) sample (male) 2 n = 42 and FN = 66. Autosomal complement: nine large to small metacentric and submetacentric pairs decreasing in size, four subtelocentric pairs (two large and two medium), and seven acrocentric pairs (two large and five medium to small). Sex chromosomes: X chromosome was a medium subtelocentric, and the presumed Y was a small submetacentric (Musser et al. 1998). According to Musser et al. (1998) the major difference between the variable karyotypes (2 n = 40 – 42) and the apparently stable karyotypes (2 n = 34) was that the latter has an entirely biarmed autosomal complement. The num-ber of acrocentric pairs varies from four to seven, not counting the unpaired element present in karyotypes with 2 n = 40 and in one with the 2 n = 41. The karyotype with 2 n = 34 was characterized by two pairs of very large submetacentric chromosomes that were conspicuous not only for their size, but also for the secondary constrictions evident in one of the pairs. This karyotype also has only one pair of large subtelocentrics. In contrast, the karyotypes with 2 n = 40 – 42 have an additional pair of large subtelomeric, but lack the two pairs of very large submetacentric. Both Robertsonian rearrangements and pericentric inversions were required to explain that karyotypic differences. The configurations of these karyotypes do not suggest supernumerary chromosome involvement. Karyotype 3: 2 n = 36 and FN = 60. Autosomal complement: two subtelocentric pairs (one large and one medium), 11 metacentric and submetacentric pairs (four large, three medium, two small, and two minute), and four acrocentric pairs (two large and two minute). Sex chromosomes: X, a medium acrocentric; Y, a small subtelocentric (Musser et al. 1998, pp. 236, Fig. 70). This karyotype was reported only for a sample from Esmeraldas, states of Ecuador (Table 10, Fig. 21). Karyotype 4: 2 n = 54 and FN = 60. Autosomal complement: four metacentric pairs (one medium, one small and two minute), and 22 acrocentric pairs (three large and the remaining medium to minute decreasing in size). Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric (Musser et al. 1998, pp. 236, Fig. 70). This karyotype was reported only for a sample from El Oro, states of Ecuador (Table 10, Fig. 21). According to Musser et al. (1998) the major differences between karyotypes 3 and 4 can be explained by either fissions or Robertsonian rearrangements. Both explanations presuppose whole-arm homologies between the chromosome set of these karyotypes, with one having been derived from the other, however, confirmation will require the analysis of banding patterns. Karyotypes from intervening populations were unknown and evidence for or against hybridization was lacking between the forms with 2 n = 36 and 2 n = 54.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326EFF8483E9FCCD2956FB76.taxon	description	The genus Zygodontomys comprises two species, the monotypic Z. brunneus (Thomas 1898), and the polytipic Z. brevicauda (Allen & Chapman 1893) (that includes Z. b. brevicauda, Z. b. cherriei (Allen 1895), and Z. b. microtinus (Thomas 1894 )) (Voss 1991). The genus occurs in unforested landscapes from the Pacific coast and foothills of eastern Costa Rica through Panama, Colombia, Venezuela, Guyana, Suriname, French Guiana, and Brazil north of the Amazon. Zygodontomys also occurs on adjacent continental-shelf islands (Trinidad and Tobago) where it may occupy forest as well as non-forest habitats. Z. brunneus was known only from the intermontane valleys of Colombian Andes and occurs sympatrically with Z. brevicauda that was more widespread, with known records from eastern Colombia throughout the Llanos, the savannas of the upper Rio Branco in Brazil, Suriname, French Guiana and Guyana (Voss 1991; Prado & Percequillo 2013). All cytogenetic data available for the genus was presented on Table 11, and the distribution of diploid and fundamental number of karyotyped specimens were presented on Fig. 22.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326EFF8783E9FB192848FEDA.taxon	description	Two different karyotypes were reported for Z. b. brevicauda. Karyotype 1: 2 n = 84 and FN = 116 or 118. Autosomal complement: one medium submetacentric pair, one medium subtelocentric pair, 18 small autosomal pairs, and 21 minute autosomal pairs. According to authors, due to the small size of most autosomes, it was hard to recognize the morphology of many of the chromosomal pairs, however based on the best-defined karyotypes the estimate of autosomal fundamental number as made of 116 or 118 arms. Sex chromosomes: X, a small subtelocentric; Y, a minute subtelocentric (Kiblisky et al. 1970; Reig et al. 1990, pp. 363, Fig. 2). A secondary constriction was observed at one small autosomal pair. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of almost all chromosomes, the medium metacentric and submetacentric pairs lack a striking heterochromatic region, five small autosomal pairs exhibit both pericentromeric and terminal heterochromatic block, three small to minute autosomal pairs presented the small arm entirely heterochromatic, five minute autosomal pairs were entirely heterochromatic, all the remaining autosomal pairs showed different degrees of Cband on the pericentromeric regions. The X chromosome presented a pericentromeric heterochromatic block, and the banding pattern of the Y chromosome was not clearly defined. According to authors, the heterochromatic nature of some short arms, may be responsible for polymorphic variants in the morphology of several autosomes among different individuals (Reig et al. 1990). Karyotype 2: 2 n = 88 and FN = 116 – 118. Autosomal complement: one medium submetacentric pair, one medium subtelocentric pair, 18 small autosomal pairs, and 23 minute autosomal pairs. Sex chromosomes: X, a small subtelocentric; Y, a minute subtelocentric (Gardner & Patton 1976; Perez-Zapata et al. 1984; Reig et al. 1990, pp. 365, Fig. 4). According to Reig et al. (1990), the difference in diploid numbers of 2 n = 84 and 2 n = 88, that occurs in different localities of Venezuela (Table 11, Fig. 22), were due to addition of two pairs of minute chromosomes. Besides, the metacentric and the submetacentric small pairs found in the 2 n = 84 karyotype was lacking in the 2 n = 88 karyotype. These differences can be easily explained by a Robertsonian rearrangement affecting two small pairs of the 2 n = 84 karyotype. C-banding was performed and a great deal of the genome were C-band positive, although the small size and high number of chromosomes hampered efforts to obtain a clear metaphase. It was evident, however, that eleven very minute autosome pairs were entirely heterochromatic, and five small autosome pairs appear to be entirely heterochromatic (Reig et al. 1990).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326DFF8783E9FAF1287BF9EF.taxon	description	The karyotypes of 2 n = 82 and 2 n = 84 were described by Gardner & Patton (1976), and Voss (1991), but in both cases the authors mention the karyotype without description or illustration of the chromosomes. Bonvicino et al. (2003, pp. 124, Fig. 2 B) described a karyotype of 2 n = 82 and FN = 116. Autosomal complement: 18 biarmed pairs (two large and 16 medium to small decreasing in size), and 22 medium to small acrocentric pairs decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a small metacentric. These variation in diploid number occurs sympatrically on specimens collected in Zulia, state of Venezuela (Table 11, Fig. 22).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326DFF8683E9F991282BF855.taxon	description	The karyotype of 2 n = 78 was reported by Tranier (1976) based on a sample from French Guiana (Table 11), but the author did not describe or illustrate the karyotype. Another karyotype was reported by Mattevi et al. (2002, pp. 36, Fig. 2) and Bonvicino et al. (2009). Karyotype: 2 n = 86 and FN = 96 to 100. Autosomal complement: two large submetacentric and subtelocentric pairs, four or five medium to small biarmed pairs, and the remaining being acrocentric. Sex chromosomes: X, a large submetacentric; Y, a medium subtelocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of the autosomes, being usually absent on the two large autosomal pairs. The short arm of the X and the whole Y chromosomes were heterochromatic. G-banding was also performed. NORs, were localized at the short arms of one medium and one small acrocentric pairs, but in two metaphase plates a third pair, a medium acrocentric, showed a NORs on its long arm.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326DFF8683E9F991282BF855.taxon	discussion	According to Bonvicino et al. (2009), the Brazilian populations of Zygodontomys presents, at least, three karyotypes reported, indicating that the diversity of this genus was underestimated in Brazil and suggesting the existence of several evolutionary lineages. Molecular phylogenetic analyses recovered three major clades congruent with known karyotypes, indicating the existence of three species, two of which currently undescribed, mentioned by the authors as Zygodontomys sp. 1 and Zygodontomys sp. 2, whose karyotypes were described below. According to Voss (2015), a more comprehensive revisionary work for the genus is still pending.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326BFF8183E9FCD82885FBF2.taxon	description	Karyotype: 2 n = 60 and FN = 104. Autosomal complement: 23 metacentric and submetacentric pairs large to small decreasing in size, and six acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a medium acrocentric; Y, a small acrocentric (Haiduk et al. 1979, pp. 611, Fig. 2 B; Baker et al. 1983). G-banding karyotype was performed by Baker et al. (1983). Another karyotype for this species was reported by Musser et al. (1998) 2 n = 62 and FN = 100. Autosomal complement: 16 metacentric and submetacentric pairs (four large, four medium, and eight small), four subtelocentric pairs (two large and two medium), and 10 acrocentric pairs (three large, three medium, and four small). Sex chromosomes: X, a large subtelocentric; Y, a small acrocentric.	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326BFF8183E9FBA42D8AFA92.taxon	description	Karyotype: 2 n = 62 and FN = 70. Autosomal complement: one medium subtelocentric pair, four metacentric pairs (one medium and three small), and 25 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large metacentric; Y, a medium subtelocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented a pericentromeric heterochromatic blocks (Haiduk et al. 1979, pp. 611, Fig. 1 A). G-banding karyotype was performed by Haiduk et al. (1979) and Baker et al. (1983).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326BFF8183E9FF502D34FE86.taxon	description	Karyotype: 2 n = 84 and FN = 96 to 98. Autosomal complement: two large submetacentric and subtelocentric pairs, four or five medium to small biarmed pairs, and the remaining being acrocentric. Sex chromosomes: X, a large submetacentric; Y, a medium subtelocentric. G-banding was also performed (Mattevi et al. 2002; Bonvicino et al. 2009).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
03A587ED326BFF8183E9FEA8281EFD36.taxon	description	Unnamed generic taxon, currently named Handleyomys These species its provisional position as a member alfaroi group because no new genus to encompass these taxa has yet been described, alfaroi (Allen 1891), chapmani (Thomas 1898), melanotis (Thomas 1893), rhabdops (Merriam 1901), rostratus (Merriam 1901), and saturatior (Merriam 1901) (Weksler 2015 a).	en	Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis, Yonenaga-Yassuda, Yatiyo (2020): A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes. Zootaxa 4876 (1): 1-111, DOI: 10.11646/zootaxa.4876.1.1
