Marmosa

Silva, Luan Gabriel De Lima, Ferreira, Daniela Cristina & Rossi, Rogério Vieira, 2019, Species diversity of Marmosa subgenus Micoureus (Didelphimorphia, Didelphidae) and taxonomic evaluation of the white-bellied woolly mouse opossum, Marmosa constantiae, Zoological Journal of the Linnean Society 187, pp. 240-277 : 265-269

MARMOSA (MICOUREUS) CONSTANTIAE THOMAS, 1904

Marmosa constantiae Thomas, 1904: 243 . Type locality ‘Chapada, Matto Grosso.’

[ Didelphys (Marmosa) ] constantiae : Trouessart, 1905: 856; name combination.

[ Didelphis (Caluromys) ] constantiae : Matschie, 1916: 270; name combination.

Geographic distribution: Marmosa constantiae occurs from eastern Peru (Río Gálvez, Loreto and Tangoshiari, Cusco) to northern Bolivia (Pando and Santa Cruz Departments) and western Brazil, in the states of Amazonas, Acre, Rondônia, western Mato Grosso and the extreme south-west of Pará (Rio Teles Pires, Jacareacanga; Fig. 5). The species occurs in sympatry with M. regina in north-eastern Peru (in Río Gálvez; Localities 19 and 20; Fig. 5), south-western Amazonas and in the east of Acre in Brazil. The species also occur in sympatry with Marmosa (Mi.) sp. A in the upper Urucu River, Amazonas State (Locality 14; Fig. 5).

Habitat: Marmosa constantiae has a broad geographic distribution spanning several ecoregions ( Olson et al., 2001), including Cerrado, Chiquitania dry forests, Pantanal, Mato Grosso tropical dry forests, south-western Amazonian moist forests, Beni savannas, Madeira/Tapajos moist forests, Iquitos várzea, Jurua/ Purus moist forests and Peruvian Yungas.

[ Marmosa (Marmosa) ] constantiae : Cabrera, 1919: 36; name combination.

M [icoureus] constantiae : Gardner & Creighton, 1989: 4 (part); name combination.

Micoureus constantiae budini : Anderson, 1997: 9 (part); name combination.

Micoureus constantiae constantiae : Anderson, 1997:9 (part); name combination.

[ Marmosa (Micoureus) ] constantiae : Voss & Jansa, 2009:101; first use of current name combination.

M [armosa]. constantatiae constantiae De la Sancha et al., 2012:232 ; incorrect spelling.

Type information: The holotype is deposited in the Natural History Museum, BMNH 3.7 .7.157, adult male (mature adult), with skin and skull well preserved, collected on 27 August 1902 by A. Robert from Chapada dos Guimarães, Mato Grosso, Brazil (Supporting Information, Fig. S1) .

Emended diagnosis: Marmosa constantiae has a relatively large body size ( HBL: 131–262 mm) and long tail (LT: 159–297 mm); very dark or blackened facial mask; dorsal fur of 8–14 mm in length, light to dark greyish-brown variably washed with orange; ventral fur yellowish-cream to yellowish-buff, with lateral bands of grey-based hairs that may or may not join at the midline of chest or abdomen; neck region more awash with orange when compared to the rest of the venter; caudal scales arranged spirally; each scale with three hairs, the central one being the longest; mammary formula 3-1-3, 4-1-4 or 5-1-5; robust skull with well-developed superior canines; posterior margins of nasals w-shaped; developed supraorbital ridges, both laterally and dorsally projected; temporal ridges moderately to strongly convergent, usually forming a sagittal crest posteriorly; interparietal bone narrow anteriorly, with medial and posterior region gradually expanding laterally; palatine fenestrae absent; developed supraorbital ridges and postorbital process; developed temporal ridges that form a sagittal crest in specimens belonging to the most advanced age classes; upper molars with incomplete posterior lingual cingulum and lower molars with incomplete labial cingulid.

Morphological description: Marmosa constantiae is a large-sized species when compared to other species of the subgenus Micoureus , with head and body length ( HBL) 131 to 262 mm and tail longer than HBL ( Table 8); rostrum lighter than the dorsum of the head, covered with cream-based and black-tipped hairs; not well-defined facial mask, wider in the upper region ( Fig. 6B); cheeks usually yellowish-buff; six to nine genal vibrissae (generally eight), three of which are long and black, and the remaining short and yellowish; dorsal hairs 8–14 mm long; dorsal fur varying from yellowish-brown to greyish-brown ( Fig. 7B, C); laterals of the body lighter than the dorsum, usually more awash with yellow or orange; ventral fur yellowish- to orangish-buff, with lateral grey-based hairs generally restricted to the thorax and abdomen, sometimes extending to the neck; ventral grey-based bands rarely joining at the midline of chest or abdomen ( Fig. 7B, C); mammary formula varying from 3-1-3 to 5-1-5; medial and lateral carpal tubercles present in mature adult males; body fur at the base of the tail 16–58 mm; tail light to dark brown, part-coloured, varying from patchily depigmented in the half distal portion on the venter of the tail to completely depigmented in the two-thirds distal part of the tail (dorsal and ventrally); tail scales arranged spirally; from the posterior margin of each scale emerges three hairs on the dorsum of the tail and one to three hairs on the venter (the number of scale hairs decrease distally along the tail); prehensile ventral surface of the tail tip on average 46 mm long.

Craniodentally, M. constantiae has a long and broad rostrum when compared to other species of the subgenus Micoureus ( Tables 6, 7); long nasal bones that extend beyond the lacrimal bones, with w-shaped posterior margins; temporal ridges moderately to strongly convergent, usually forming a sagittal crest posteriorly ( Fig. 8B); interparietal bone narrow anteriorly, gradually expanding laterally toward its posterior margin ( Fig. 9B); two lacrimal foramina generally exposed in lateral view (sometimes one of these foramina lies deeper in the orbital cavity, being not exposed in lateral view); infraorbital foramen aligned with the third upper premolar; jugal extends over the squamosal to form the zygomatic process of the squamosal; anterior margin of incisive foramina usually aligned with the fourth upper incisive and posterior margin aligned with the upper canine; palatine fenestrae absent ( Fig. 10B) or diminutive perforations rarely present in one or both sides of the palatine ( Fig. 10C); tympanic process of alisphenoid globular or (less frequently) slightly compressed ( Fig. 11B); anteromedial process of the tympanic process of the alisphenoid usually absent (if present, it is small and laminar); cochlear fenestra usually exposed in ventral view ( Table 8); mental foramina aligned with either the first lower premolar or the first lower molar; upper canine high, usually without posterior accessory cusp (if present, mostly in females, it is incipient); crowns of upper second to five incisors (I2–I5) triangular, longer in I5; upper molars with incomplete posterior lingual cingulum that ends at the height of the metacone ( Fig. 12B); lower molars with incomplete labial cingulid that ends at the height of the protoconid ( Fig. 12D).

Comparison with other Micoureus species: Comparisons between M. constantiae and M. budini are provided above. Although M. constantiae and M. demerarae (sister species) presented great overlap in the PCA and DA analyses, M. constantiae has a larger (e.g. GLS and CBL) and wider (e.g. BBC and ZB) skull in relation to M. demerarae and in relation to the other species.

Externally, M. constantiae does not have a well-defined facial mask, discriminating this species from M. demerarae and M. regina , which possess a well-defined facial mask with a wider upper region. In addition, M. demerarae differs from M. constantiae by having a facial mask with a sharpened posterior margin ( Fig. 6). Marmosa constantiae has woollier body fur than M. regina , but smoother fur than M. paraguayana . The body fur is also denser in M. constantiae when compared to M. paraguayana . The ventral fur varies from yellowish-cream to yellowish-buff, with lateral bands of grey-based hairs that may or may not join on the midline of the chest or abdomen ( Fig. 7B, C). In contrast, M. demerarae ( Fig. 7D) and M. paraguayana have yellowish-cream to yellowish-buff ventral fur in the former and yellowish-cream ventral fur in the latter, with dark grey-based hairs throughout the venter in both (neck, chest, abdomen and inguinal region). Marmosa regina has yellowish-cream ventral fur with lateral bands of hairs that broaden (but never join medially) on the abdomen. The body fur at the base of the tail is moderately long in M. constantiae (33.7 ± 8.3 mm, N = 237) and M. demerarae (35.8 ± 5.8 mm, N = 59), whereas it is longer in M. paraguayana (44.1 ± 8.5 mm, N = 10) and shorter in M. regina (up to 20 mm; Table 8).

In relation to the skull, Marmosa constantiae has moderately to strongly convergent temporal ridges, differing from M. paraguayana that has parallel temporal ridges.Among the older adult male specimens of M. constantiae , 65.5% have a sagittal crest ( Fig. 8), a character not observed in any other species. Marmosa constantiae has globular or slightly compressed tympanic process of the alisphenoid, whereas this trait is always globular in M. paraguayana and M. demerarae and always slightly compressed in M. regina ( Fig. 11). The cochlear fenestra is exposed in ventral view in M. regina , usually exposed in both M. constantiae and M. demerarae , but not exposed in M. paraguayana . As for palatine fenestration, M. constantiae and M. demerarae may rarely have one or two distinct miniature orifices in each half of the palatine ( Fig. 10). These holes are not found in M. regina and M. paraguayana . Dentally, the crown of I2 is triangular in all the analysed species, but it is noticeably wider than its root in M. constantiae and M. demerarae , a characteristic absent in the other species.

Intraspecific morphological variation: Individuals collected in open areas, such as Cerrado, Pantanal and Chiquitania dry forest, present lighter dorsal and ventral coloration and more orange lateral sides when compared to individuals from forested areas ( Fig. 7B, C). Individuals of older age classes can present infratemporal ridges on the alisphenoid.

in January in Vilhena, state of Rondônia, Brazil and in September in the municipality of Colíder, state of Mato Grosso, Brazil.

Reproduction information: Based on the analysis of 41 females, it was possible to verify that M. constantiae presents the following mammary formulas: 3-1-3 = 7 (N = 4); 4-1-4 = 9 (N = 22) and 5-1-5 = 11 (N = 15). Although Tate (1933) reported the mammary formula 7-1-7 for the species, we found no specimens with this condition. According to tag and field notes, lactating females with nine to 10 young were collected in the municipalities of Claudia and Sinop, state of Mato Grosso, Brazil. Lactating females were also recorded