taxonID	type	description	language	source
C55887A817513B29CDB6FE98675E658B.taxon	materials_examined	Holotype. MCZ 602 s, juvenile male, coll. Thayer Expedition (Figs. 2 – 5). Type locality. Rio Tocantins at Cametá, Pará state, Brazil.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817513B29CDB6FE98675E658B.taxon	diagnosis	Diagnosis. Potamotrygon scobina is distinguished from congeners by a combination of characters: disc dark brown to dark gray with relatively small beige to yellow ocelli with thin dark brownish contours; ocelli usually smaller on central disc, varying in number and size, sometimes forming rosette-like patterns or grouped around a central larger ocellus; ventral disc whitish, with darker blotches over posterolateral margins; tail dark, with nonocellated, irregular, light colored spots; labial folds absent; teeth small, with a single low cusp; dermal denticles small and relatively few in number, concentrated mostly on central disc; disc margins usually lacking denticles; rostral denticles simple, composed of a single central crown; head denticles with low, star shaped crowns; caudal denticles with same pattern as head, but smaller; one or two irregular rows of thorns on dorsal tail midline, always converging to a single row posteriorly; thorns relatively large and curved; tail long and slender, with a narrow base; cartilaginous rod notably very long and thin; a third, smaller, lateral angular cartilage present. Potamotrygon scobina is distinguished from congeners by its color pattern (further detailed below) and in having a third, smaller, lateral angular cartilage, except P. limai, P. adamastor sp. nov., P. garmani sp. nov., and P. amazona sp. nov. From P. limai, P. scobina is further distinguished by lacking its polygonal color pattern on disc, and by having a thinner tail and dermal denticles with lower crowns and fewer dichotomies. From P. amazona sp. nov. and P. adamastor sp. nov., by having a less muscular disc in adults, comparatively smaller and fewer dermal denticles, larger and better defined ocelli on disc, and a more slender and longer tail (mean tail width 13.4 % DW vs. 19.0 % DW in P. adamastor sp. nov. and 16.7 % DW in P. amazona sp. nov.; mean tail length 121.5 % DW vs. 78.1 % DW in P. adamastor sp. nov. and 89.3 % DW in P. amazona sp. nov.). From P. garmani sp. nov., P. scobina is differentiated by presenting a darker disc background, smaller ocellated spots, a longer and more slender tail (mean length 121.5 % DW vs. 100.6 % DW in P. garmani sp. nov.; mean width 13.4 % DW vs. 14.1 % DW in P. garmani sp. nov.), more tooth rows in both jaws (44 / 48 – 50 vs. 32 – 40 / 33 – 40 in P. garmani sp. nov.), and in having comparatively smaller thorns in dorsal mid tail series.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817513B29CDB6FE98675E658B.taxon	description	Description. Disc oval, slightly longer than wide (DL 98.8 – 112.4 % DW) (Figs. 2, 6). Rostral portion of disc broadly oval, presenting a small round protuberance on anterior snout (Figs. 3 a, 7 a). Disc dorsoventrally slender and comparatively thin at margins. Eyes small and oval (mean 3.0 % DW), around two times smaller than spiracles; spiracles rhomboidal, obliquely set just posterior to eyes (Figs. 3 a, 7 a). Head flat, low, not abruptly or significantly raised above disc, head length about 1 / 3 of disc length, with interorbital distance 12.9 – 17.5 % DW, and interspiracular distance 15.9 – 21.5 % DW. Nasal curtain extending to mouth opening. Mouth small and lightly undulated or convex, with a central notch; mouth width 7.1 – 12.5 % DW, and internasal distance 7.3 – 9.2 % DW (Figs. 3 b, 7 b). No labial folds or ridges present. Five buccal papillae present on mouth floor, two posterior and three anterior; three papillae in a single row on mouth roof. Branchial basket wider than long, with distance between first branchial slits 23.1 – 29.0 % DW, and distance between fifth branchial slits 15.9 – 21.2 % DW. Teeth small, simple and rounded, wider than long, set in quincunx on narrow and arched upper tooth plate, and wide and trapezoidal lower tooth plate (Figs. 4 a – d, 8). Tooth row count 40 in upper jaw and 48 – 50 in lower jaw. Adult males presenting a single, central pointed cusp on midrow teeth in both jaws. Lateral teeth in adult males, juvenile males, and females simple, with a single rounded cusp. All teeth with a single cutting surface. Lower jaws considerably wider than upper jaws, always with more tooth rows. Pelvic fins broad, subtriangular, their length ranging from 23.7 – 60.3 % DW (mean 52.8 % DW), with rounded apices and undulated posterior margins (Figs. 3 d, 7 d). Pelvic fin posterior margins project slightly beyond posterior disc. Anterior pelvic margin length varying from 20.5 – 27.8 % DW. Claspers robust, long and dorsoventrally compressed (Fig. 7 d). Clasper base more robust and wider than clasper tip. Clasper external length 3.9 – 14.2 % DW, and internal length 7.9 – 21.5 % DW (considering juveniles and adults). Clasper groove curved medially, with a semicircular apopyle, and an oval and large hypopyle. Dorsal pseudosiphon oval, obliquely positioned. Ventral pseudosiphon well developed, elliptical and medial. Tail slender, long and well developed (Figs. 6, 7 c). Tail width ranging from 10.1 – 20.2 % DW (mean 13.4 % DW), and length ranging from 76.3 – 145.2 % DW (mean 121.6 % DW). Tail narrows only slightly from base to caudal sting origin, then tapers posteriorly more intensely toward extremity. Long and slender cartilaginous rod present internally in tail more or less as of caudal sting, its length generally 1 / 2 – 2 / 3 of total tail length. A single irregular dorsal row of tail thorns present; thorns with a wide and round basal plate and posteriorly curved, only moderately developed crown; sometimes two irregular rows present on tail base. Tail also with small and scattered denticles. Small, single lateral row of spine on tail, originating at caudal sting origin. Caudal sting length 13.8 – 25.8 % DW. Coloration. Dorsal disc dark brown to dark gray (Figs. 3 c, 9), with small white to yellow irregular spots, varying in number. Beige to yellowish ocelli present, their outer halo thin, darker, and poorly defined; ocelli same size or smaller than eyes, but usually larger between disc margins and center; ocelli spread over all of disc. Smaller irregular whitish spots sometimes present, set around a central, larger ocellated spot. Four main color patterns observed, but intermediate specimens also exist: (i) disc dark brown, with relatively large ocelli varying in quantity, and without accessory smaller spots; (ii) disc dark brown, with large ocellated spots, and with accessory small and irregular whitish spots mainly on posterior dorsal portion of disc; (iii) disc dark brown, with few, small ocelli, and sometimes very small accessory spots; (iv) disc dark background with numerous irregular whitish spots, sometimes organized around ocelli; ocelli sometimes discernible only on disc margins, but present on tail base and dorsal pelvic fins. Ventral disc white to creamy-white, sometimes with central darker spot. Subadults and adults with ventral posterolateral dark gray blotches on disc, extending anteriorly to level of pectoral girdle. Ventral darker pigmentation age related; younger specimens generally lighter. Dorsal pelvic fins with same pattern as disc margins, with a dark background and ocellated spots. Posterior pelvic margin with lighter color. Ventrally, pelvic fins light with a posterior dark margin, varying with specimen size and age. Claspers dorsally with same background pattern as pelvic fins, but with irregular clear spots, without ocelli. Ventrally, claspers dark. Dorsal tail dark, similar to dorsal disc color, covered by small irregular, whitish spots. Lateral tail with small, spaced groupings of very small whitish irregular spots. Ventrally, tail whitish, covered by dark blotches, continuous with those of disc. Dark blotches progressively smaller from anterior to posterior tail. Adults may present a more uniform dark ventral tail. Newborn specimens may present proportionally larger marginal ocelli combined with a central roughly hexagonal pattern of smaller spots on disc (newborn frequently misidentified as P. motoro or P. orbignyi). Dermal denticles. Dermal denticles small and comparatively few, present on central snout, head, posterocentral disc, and dorsal and lateral tail (Figs. 4 e – h, 10, 11). Disc margins smooth, denticles either absent or very small and sparse. Simple denticles present between eyes in a semicircular pattern, with a single, low pointed crown. Denticles usually uniform in size, but larger denticles reach up to twice size of smaller denticles. Denticle basal plate (Bp) rounded and low. Denticles on head and central posterior disc regions star shaped, with a posteriorly set, well-developed coronal plate (Cp). Anterior end of coronal plate wider and obliquely set. Two anterior coronal ridges (Cr) present with two different levels, marked by a central rounded notch, and converging to anterior end of coronal plate. Two posterior coronal ridges present, straight and opposite, laterally set to posterior end of coronal plate. Irregular coronal dichotomies (Cd) sometimes present on coronal ridges. Denticles of caudal region with well-developed coronal plates, curved posteriorly, with two anterior and two lateral posterior coronal ridges. Basal plate fairly prominent on disc denticles. Caudal denticles more prominent, simpler and with more slender crowns than denticles on central disc. One irregular row of enlarged thorns over most of tail, with one to two irregular thorn rows over tail base. Enlarged thorns moderately robust, presenting a single posteriorly set crown and semi-oval basal plate. Lateral caudal spine rows sometimes present, posterior to origin of caudal sting, and composed of minute denticles with single crowns. Ventral lateral-line canals. (Fig. 12). Hyomandibular canal (HYC) projecting anteriorly from the nostril and obliquely towards disc margins, curving posteriorly following anterolateral disc margin. Anterior subpleural tubules (AST) short and straight. Subpleural component of the hyomandibular canal (SPC) slightly undulated, projecting posteromedially. Hyomandibular canal abruptly curves inward by anterior margin of pelvic fin, forming the subpleural loop (SPL). Posterior subpleural tubules (PST) absent. Jugular component (JCH) projects anteriorly and obliquely, bordering external margin of branchial basket. Jugular canal (JUG) curved externally, extending anteriorly to the small loop formed by the supraorbital canal (SOC). From the posterior jugular loop (PJL), the posterior portion of the infraorbital canal (IOC) projects posteroexternally forming the external margin of the short posterior jugular loop (PJL). Infraorbital canal extends anteriorly, parallel to the anterior expansion of the hyomandibular canal. At its most anterior segment, the infraorbital canal curves medially to delimit the anteriorly positioned suborbital loop (SOL). Nasal canal (NAS) projects anteriorly, curving medially as it reaches nostril. The orbitonasal component (CON) of the supraorbital canal (SOC) extends anteromedially from the confluence between the jugular and nasal canals, forming the lateral margin of the anterior jugular loop (AJL). The orbitonasal component extends toward the ventral snout area, presenting undulations varying in size, and forms the lateral margin of the acutely shaped prenasal loop (PNL). Skeletal morphology. Neurocranium. Nasal capsules ventrolaterally expanded (NC) (Figs. 5, 13), their anterior margin oval and convex. Precerebral fontanelle (PCF) wide and subcircular, with straight anterior margins, posteriorly delimited by a subtriangular epiphysial bar (EBP). Frontoparietal fontanelle (FPF) coneshaped, progressively narrowing posteriorly, presenting a slight median constriction, with a round posterior margin at posterior level of postorbital processes. Together, both fontanellae keyhole-shaped. Supraorbital processes (SOP) small, subtriangular, laterally projected. Postorbital process (POP) prominent, long and wide, diagonally projected anteriorly, extending to level of posterior angular cartilage. Prespiracular cartilage (psc) curved, forming a concave anterior wall to the spiracle. Jaws and hyomandibular arch. Hyomandibular cartilage (HYO) elongated and anterolaterally projecting from neurocranium, bearing a slight lateral constriction close to posterior extremity; anterior margin of hyomandibulae curved (Figs. 5 b, d, 13 b, d, 42). Three angular cartilages present. Anterior angular cartilage (AAC) concave, about 1 / 4 length of hyomandibulae. Posterior angular cartilage (PAC) oval, around same size of anterior angular cartilage, but more slender than anterior angular cartilage. Lateral angular cartilage (LAC) subcircular and small, set between posterior angular cartilage and hyomandibulae, around 1 / 3 length of posterior angular cartilage. Meckel's cartilage (MC) robust, its internal margin with subrectangular corners, and rounded external margins. Well defined, central concavity present on anterior margin of Meckel's cartilage. Posterior margin bearing a prominent, anterior ventrolateral process (VLP), not contacting angular cartilages, and a robust anterolateral process (LAP). Palatoquadrate (PQ) smaller and more slender than Meckel's cartilage, with a posterior concavity, laterally limited by a small triangular projection. Posterior triangular projection (PTP) well developed. Small ligament present between palatoquadrate antimeres. Synarcual cartilage. Anterior synarcual articulates with neurocranium through a rounded, central odontoid process (Fig. 5 b). Medial crest extending over almost entire synarcual length, but not reaching its anterior extremity. Articular surfaces for scapular processes laterally projected, separated by concavity on each side. Anterior articular surface slightly rectangular and more prominent then rounded and lateroposteriorly projected posterior articular surface. Pectoral girdle. Pectoral girdle articulates with synarcual through robust scapular processes (Figs. 5 a, 13 c). Anterior process slender and straight, projected diagonally; posterior process more robust, with a small rounded extremity delimiting an adjacent concavity. Scapular process presents a biconcave medial bar, with considerably expanded lateral portions. Procondyle (PRC) anteriorly positioned, rounded. Mesocondyle (MSC) rounded, anterolaterally positioned; metacondyle (MTC) rounded, but less so, posteriorly positioned. Robust and elongated propterygium (PRO) articulated anteriorly to procondyle and scapular girdle. Mesopterygium (MES) small, its anterior margin more developed, articulating to shoulder girdle near mesocondyle. Metapterigium (MET) posteriorly set and elongated, articulates at level of metacondyle (MTC), and curved, projecting posteriorly. Pelvic girdle. Prepelvic process (PPP) elongated, anteriorly projected, bordered by anterior concavities of pubosquiadic bar (PIB); puboischiadic bar with expanded extremities (Figs. 5 c, 13 e, f). Evident subtriangular lateral prepelvic processes (LPP) present. Iliac processes (IP) laterally and posteriorly set and robust. A slender and subtriangular isquial process (ISP) set more medially, projecting posteriorly. Between both isquial processes, four well developed obturator foramina (OF) present on each side. Clasper skeleton. Basal segment 1 (B 1) with a wider anterior margin (Figs. 13 f, 14); both margins oval. Basal segment 2 (B 2) cylindrical, with a central concavity on its external wall. Both basal segments about equal in length, but segment 2 more slender. Axial cartilage (AX) elongated and cylindrical, robust, curved externally, S-shaped posteriorly. Ventral marginal cartilage (VM) diamond-shaped, projecting laterally and ventrally. Beta cartilage (BE) slender and cylindrical, about 1 / 2 of total clasper length, and externally curved, articulating with basal segment 1. Dorsal marginal cartilage (DM) well developed and oval, about 1 / 4 in total clasper length, curved internally. Dorsal terminal 2 (DT 2) oval, slightly slender and curved, presenting a small concavity on its anterior margin. Accessory terminal cartilage (AT) straight, more robust than dorsal terminal 2, dorsal marginal and ventral marginal cartilages, with a curved anterior margin. Ventral terminal cartilage (VT) well developed, about 1 / 3 of clasper length, with a dilated posterior portion but rest of structure dorsally curved, almost completely covering accessory terminal cartilage.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817513B29CDB6FE98675E658B.taxon	materials_examined	Geographic distribution. Potamotrygon scobina is widely distributed in the Amazon basin (Fig. 43). Examined specimens are from rio Tocantins (including specimens from very close to type locality) and rio Madeira systems, as well as from rios Amazonas and Solimões. There are also records from río Orinoco in Colombia and Venezuela (Rosa et al. 2014; also possibly Ross & Schäfer 2000), and scobina - like specimens occur as far as rio Nanay, in Peru (M. Kolmann, pers. comm); many of these require further checking as we were not able to examine material from countries other than Brazil.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817513B29CDB6FE98675E658B.taxon	discussion	Remarks. Although not greatly detailed in the diagnosis above, P. scobina can be distinguished from congeners by its dorsal color pattern (for more information on species listed below, see Silva & Carvalho 2011, 2015, Loboda & Carvalho 2013, Fontenelle et al. 2014, Carvalho et al. 2016, and Carvalho 2016 a – c). From P. motoro, P. ocellata and P. boesemani, P. scobina is distinct in lacking red to orange contours in ocelli, which are usually smaller in P. scobina. From P. signata, P. magdalenae, P. pantanensis, P. amandae, P. falkneri, P. histrix, P. schuhmacheri, and P. tatianae by lacking complex patterns of vermiculate, oval or reniform spots. From P. brachyura, P. orbignyi, P. marinae, P. constellata and P. humerosa, P. scobina is distinguished by not having a complete or incomplete reticulated dorsal color pattern. From P. albimaculata, P. rex, P. leopoldi and P. henlei by lacking bright yellow to orange dorsal spots and / or ocelli over a blackish-brown background; from P. schroederi and P. tigrina by not having a vivid yellow and black vermiculate pattern; from P. jabuti by lacking its conspicuous ocelli and complex pattern of vermiculate markings; from P. yepezi by not having a gray dorsal color with small, irregular black spots; and from P. wallacei by not having its distinct amphora-shaped mark on dorsal mid-disc. In terms of color pattern, P. scobina is most similar to P. limai, P. adamastor sp. nov., P. garmani sp. nov., and P. amazona sp. nov. (see Diagnosis above for their separation). Garman (1913) did not designate a holotype for P. scobina in his original description. However, he described this species based on a single juvenile male. Sex, maturity, size, measurements and label and registration information of specimen MCZ 602 s are compatible with Garman's description, and therefore it is the holotype, as previously found by Rosa (1985) and Carvalho et al. (2003). The holotype is in acceptable condition, presenting a practically intact disc but with some lacerations, such as the removal of a dorsal skin fragment near the neurocranium, dissection of the jaws, and the lack of most of the tail. Its coloration is extremely faded, aside from few regions on the left disc where the original color pattern can be verified. In general, this specimen provides a fair amount of informative data, but the long and slender tail, with an elongated cartilaginous rod, a fundamental character to identify this species, is lacking in the holotype. Garman (1913) does not write about the tail in his original description probably because it was already missing; he also does not mention dorsal disc denticles, only the thorns of the dorsal tail rows (two irregular rows anteriorly, merging into a single irregular row posteriorly, composed of moderately developed hook-shaped thorns with a broad base). Rosa (1985) refers to these rows as parallel and irregular, and composed of low thorns (in relation to their basal diameter); Rosa also refers to the denticles on dorsal disc, these being small and more developed on central disc. Regarding disc dimensions, Garman only presents the length and width of the specimen (9.75 inches [= 247.6 mm] in length by 9.4 inches [= 238.7 mm] in width), while Rosa presents proportions between these dimensions (disc length ranging from 1.03 to 1.1 times disc width). There are no original drawings of the holotype. Garman's (1913) original description of this species, based solely on the holotype (a juvenile male lacking the tail), was based on the following characters: disc round, with a small protuberance on anterior snout; mouth small, its width 1 / 3 distance between snout and mouth, mouth opening slightly undulated, oral epithelium with 5 internal papillae in two rows, anterior row with a bifid central papilla, posterior row bearing two papillae; teeth small, with transversally concave, smooth cusp; eyes small; spiracles slightly larger than eyes; interspiracular distance contained in 1.5 times distance between eyes and anterior snout; dorsal disc and tail covered with small and closely set denticles, with star-shaped bases; denticles greater on head, central disc region and anterior tail; enlarged dorsal tail thorns anteriorly in two irregular rows; thorns low, hook-shaped, with wide bases, and extending posteriorly on tail; ventral portion of disc smooth; dorsal disc brownish, with few sparse whitish spots; ventral disc lateroposteriorly brownish, with small white spots and brown blotches. These characters described by Garman (1913) are consistent with specimens from the lower Amazon and lower Tocantins rivers, and some regions of rio Madeira, but also apply to specimens that represent distinct species similar to P. scobina discovered in the present study (described below). Rosa's (1985) study was the first to provide clear, unequivocal diagnostic characters for this species: subcircular disc (oval not round), with dorsal color pattern between light and dark brown bearing small yellow to white spots; teeth presenting flat crowns, wider than long; tail dorsal thorns relatively low in relation to the diameter of their bases, set in irregular parallel rows. Rosa (1985) also correctly indicated that Castex (1967) misidentified the holotype of P. scobina as a specimen of P. motoro, and presents diagnostic characters for both species (P. scobina has smaller teeth, less sharp and smaller thorns on dorsal tail, and lacks large ocellated spots on dorsal disc). We have increased this distinction to include differences in tail length, as the tail in P. scobina is considerably longer, the lack of red to orange contours in ocelli, and by presenting a comparatively more dorsoventrally slender disc. Rosa (1985) and Garman (1913) also describe P. scobina as bearing light colored spots on dorsal disc, a character that is indeed consistent in this species, but we note that the presence of darker halos forming ocelli is common. Rosa's (1985) measurements and counts for P. scobina are generally within the ranges reported in the present study (for details, see Rosa 1985: table 21, p. 327). For tail length, as Rosa did not have access to specimens with intact tails, his reported values are expectedly smaller than the ones presented here. Regarding counts, there are overlapping ranges between Rosa's and our data, even though Rosa's data are from a much smaller number of specimens. It is important to note that some of our counts overlap with Rosa’s at the higher end of the range; for example, the number of caudal vertebrae (101 – 108 in this study, 97 – 101 in Rosa, 1985). This is probably a function of the different number of analyzed specimens. Our data concerning number of tooth rows is the only count that does not match Rosa’s or Garman’s accounts. We found 44 / 48 – 50 tooth rows, while Rosa presents 30 – 36 / 32 – 40 and Garman 34 / 25. This discrepancy is probably due the size of the specimens examined, as we examined many large specimens not available for their studies.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817513B29CDB6FE98675E658B.taxon	materials_examined	Additional material. (53 specimens). MCZ 602 s (holotype, juvenile male, 238 mm DW), rio Tocantins, Cametá, Pará, Brazil; UFRO-I 0 0 0 515 (juvenile male, 310 mm DW), Foz do igarapé Karipuna, rio Madeira, Jaciparaná, Rondônia, Brazil, 9 ° 17 ’ 4.29 ” S, 64 ° 23 ’ 56.67 ” W; INPA uncat. field no. E 3 188773 (male), same data as UFRO-I 000515; INPA 1774 (adult male, 330 mm DW), rio Uatumã (Balbina), Presidente Figueiredo, Amazonas, Brazil; INPA uncat., field no. Ari 66 (juvenile male, 278 mm DW), rio Aripuanã, Amazonas, Brazil; INPA uncat. (juvenile? female, 206 mm DW), same data as INPA “ Ari 66 ”; INPA 29507 (adult female, 620 mm DW), same data as INPA “ Ari 66 ”; INPA 15113 (juvenile male, 183 mm DW), Careiro perto da Balsa, rio Solimões, Amazonas, Brazil; INPA 9096 (juvenile male, 298 mm DW), Janauacá, rio Solimões, Amazonas, Brazil, 3 ° 17 ’ 41.57 ” S 60 ° 20 ’ 31.34 ” W; INPA 9104 (adult male, 547 mm DW), same data as INPA 9096; INPA 10395 (adult male, 328 mm DW), same data as INPA 9096; MPEG uncat., field no. 910 (juvenile male, 347 mm DW), Ilha de Colares, rio Tocantins, Pará, Brazil; MPEG uncat., field no. 903 (subadult male, 321 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 888 (79) (female, 365 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 38 (adult male, 520 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 63 (adult female, 595 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 0 5 (juvenile male, 516 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 19 (juvenile male, 305 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 39 (adult male, 386 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 0 29 (female, 381 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 392 (adult male, 416 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 390 (female, 372 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 385 (adult male, 364 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 494 (female, 326 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 496 (subadult male, 356 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 282 (adult male, 365 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 583 (adult female, 389 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 0 53 (adult female, 611 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 729 (adult male, 408 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 843 (adult male, 403 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 726 (adult female, 406 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 744 (adult male, 341 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 727 (female, 316 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 742 (adult female, 660 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 747 (adult male, 470 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 2 F 2 / 2 0 4 832 (adult male, 392 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 837 12 (subadult male, 368 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 746 (subadult male, 328 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 738 (subadult male, 347 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 741 (adult female, 433 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 740 (adult female, 378 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 748 (adult male, 464 mm DW), same data as MPEG uncat., field no. 910; MPEG uncat., field no. 786 (adult female, 411 mm DW), same data as MPEG uncat., field no. 910; MZUSP 104247 (adult male, 503 mm DW), Baia de Marajó, Colares, rio Tocantins, Pará, Brazil, 0 ° 55 ’ 34.68 ” S, 48 ° 17 ’ 25.44 ” W; MZUSP 104245 (adult male, 543 mm DW), same data as MZUSP 104247; MZUSP 104244 (adult male, 378 mm DW), same data as MZUSP 104247; MZUSP 104256 (adult male, 414 mm DW), same data as MZUSP 104247; MZUSP 104261 (female, 314 mm DW), same data as MZUSP 104247; MZUSP 104243 (adult female, 459 mm DW), same data as MZUSP 104247; MZUSP 104258 (adult female, 405 mm DW), same data as MZUSP 104247; MZUSP 104259 (adult female, 298 mm DW), same data as MZUSP 104247; MZUSP 104266 (adult male, 392 mm DW), same data as MZUSP 104247; MZUSP 104262 (adult male, 426 mm DW), same data as MZUSP 104247; MZUSP 104257 (adult male, 429 mm DW), same data as MZUSP 104247; MZUSP 104268 (adult female, 396 mm DW), same data as MZUSP 104247; MZUSP 104246 (adult male, 412 mm DW), same data as MZUSP 104247.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817403B1CCDB6F95661F962E6.taxon	materials_examined	Holotype. MZUSP 104662 (adult female, 545 mm DW), rio Urariquera, rio Branco basin, municipal district of Boa Vista, upper Amazon Basin, state of Roraima, Brazil, 3 ° 22 ’ 51.9594 '' N, 60 ° 35 ’ 44.1594 '' W, Feb. 2007, coll. M. R. de Carvalho et al. (Fig. 15). Paratype. MZUSP 104664 (adult female, 450 mm DW), rio Branco basin, rio Urariquera, municipal district of Boa Vista, upper Amazon Basin, state of Roraima, Brazil, 3 ° 22 ’ 51.9594 '' N, 60 ° 35 ’ 44.1594 '' W, Feb. 2007, coll. M. R. de Carvalho et al. (Fig. 16).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817403B1CCDB6F95661F962E6.taxon	diagnosis	Diagnosis. Potamotrygon adamastor sp. nov. is distinguished from congeners, except P. limai, P. scobina, P. garmani sp. nov., and P. amazona sp. nov., by a combination of characters: dorsal disc dark gray covered with scarce small yellow to white ocelli with a slender dark contour; small irregular spots sometimes present on disc margin; rostral and caudal dermal denticles with a single pointed crown; a single irregular row of enlarged thorns on dorsal tail midline; tail base wide and robust; three angular cartilages of different sizes between jaw and hyomandibula; cartilaginous rod in tail relatively short (smaller than the distance between cloaca and caudal sting origin). Potamotrygon adamastor sp. nov. is distinguished from P. limai by having ocellated spots, not having a light polygonal pattern over the lower back, by having a wider and shorter tail, and fewer thorn rows over dorsal tail midline. From P. scobina and P. garmani sp. nov., by having a considerably thicker, more muscular disc, dermal denticles with fewer dichotomies and smaller basal plates, fewer spots, and a wider and shorter tail (mean tail width 19 % DW vs. 13.4 % DW in P. scobina and 14.1 % DW in P. garmani sp. nov.; mean tail length 78.1 % DW vs. 121.5 % DW in P. scobina and 100.6 % DW in P. garmani sp. nov.). Finally, P. adamastor sp. nov. is distinguished from P. amazona sp. nov. by having fewer dermal denticles on disc, a less elaborate dorsal color pattern (simple and usually with small ocellated spots with dark halos vs. numerous white spots forming clusters in P. amazona sp. nov.), and a shorter tail (mean tail length 78.1 % DW vs. 86.1 % DW in P. amazona sp. nov.) and internal cartilaginous rod.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817403B1CCDB6F95661F962E6.taxon	description	Description. Disc oval, slightly longer than wide (DL 103.7 – 107.3 % DW) (Figs. 15, 16). Anterior margin of disc broad, without a small protuberance on snout (Fig. 17 a). Disc robust, muscular and dorsoventrally thick. Eyes small and oval, around 2.5 times smaller than spiracles; spiracles obliquely positioned to eyes and trapezoidal to oval (Fig. 17 a). Head region large and protruding, slightly more than 1 / 3 of disc length, with interorbital distance 14.1 – 17.6 % DW, and interspiracular distance 16.5 – 19.7 % DW. Jaw musculature robust, evident dorsally anterior to eyes (Fig. 17 a). Nasal curtain partially covering mouth. Mouth small and lightly undulated (mouth width 8.0 – 9.3 % DW), about equal to internasal distance. Labial ridges absent (Fig. 17 b). Five buccal papillae present, two posterior alternating with three anterior. Branchial basket wider than long, with space between first branchial slits 26.9 – 30.2 % DW, and distance between fifth branchial slits 18.4 – 22.1 % DW. Teeth small and numerous in each jaw, wider than long, set in quincunx, in a narrowly arched upper tooth plate and a wide and trapezoidal lower tooth plate (Fig. 18). Tooth rows varying from 50 – 56 in upper jaw and 45 – 60 in lower jaw. Adult males presenting a single central pointed cusp on central teeth of both jaws. Lateral teeth, and teeth of juvenile males and females simple, presenting a single but more rounded cusp. Pelvic fins broad (their length 52.0 – 54.2 % DW), subtriangular, with rounded apices and a slightly undulated posterior margin. Pelvic fins extend beyond posterior disc (Figs. 17 c, d). Length of anterior margins of pelvic fins ranging from 17.9 – 25.5 % DW. Claspers robust, their posterior tips slightly curved and rotated on clasper axis (Fig. 17 e). Clasper groove long, somewhat sinuous; apopyle at level of posterior margin of pelvic fins; hypopyle just anterior to clasper flap. Dorsal pseudosiphon oval, medial to clasper groove. Tail width ranging from 17.6 – 20.8 % DW. Tail long, narrowing more intensely from origin of caudal stings (Figs. 15, 16). Cartilaginous rod short and robust. Tail with many lateral, pointed denticles. Dorsal and ventral caudal folds present on tail tip. Length of caudal stings vary from 13.9 – 21.6 % DW. Coloration. (Fig. 19). Dorsal disc dark grayish to brown, with white to yellow ocelli, with a darker contour; ocelli small, up to 2 / 3 eye length and surrounded by smaller, irregular light colored spots. Spots more numerous on disc margins. Ventral disc white to beige, with lateroposterior margins covered by dark blotches; dark color pattern not reaching anterior disc margin. Intensity of pigmentation age and size dependent; older specimens more pigmented. The only male observed (MZUSP 104654) presents larger ocellated spots compared to females of equivalent size. This variation may be due to sexual dimorphism, however since only a single adult male specimen was examined, further investigation is necessary to verify this. TABLE ³. Morphometric đata for P. adamastor sp. nov. SD: stanđarđ đeviation. Pelvic fin dorsal surface with same color pattern as disc margin, with light colored posterior margin. Ventrally, pelvic fins whitish with a posterior darker margin. Claspers also lightly colored and covered posteriorly with darker blotches. Tail with dark dorsal background, similar to disc, but without ocelli. Numerous small irregular spots randomly present on tail. Tail with small groupings formed by tiny light colored irregular spots at sides, over dark background, without ocelli. Ventrally, tail lighter, covered by dark blotches on almost entire ventral surface; blotches increase in size from lateral to central tail. Sometimes with light colored blotches inside darker blotches. Dermal denticles. (Fig. 20). Disc covered with dermal denticles in three different regions. Rostral region presenting simple denticles, with a single pointed crown. Basal plate (Bp) indistinct, with slight basal ridges (Br) when present. Head and mid-region of disc with denticles with a long coronal plate (Cp), posteriorly oriented, with a single anterior dichotomy composed of two well-developed coronal ridges (Cr). Caudal region with simple denticles, with a single pointed crown plate, without dichotomies. Basal plate circular, simple and indistinct, with small basal ridges sometimes present converging to denticle center. Ventral lateral line canals. (Fig. 21). Hyomandibular canal (HYC) extending from anterior to nostrils, contacting orbitonasal component of supraorbital canal (CON), and projects to anterior disc margin before curving posteriorly. Anterior subpleural tubules (AST) not observed. Hyomandibular canal extends posteriorly (as the subpleural component of the hyomandibular canal; SPC), curving medially at about level of first branchial slits. Subpleural loop (SPL) not broad, deflected cranially just anterior to level of pelvic fin insertions. A single posterior subpleural tubule (PST) present between subpleural loop and jugular component of hyomandibular canal (JCH). Jugular component extends anteriorly, deflecting medially anterior to branchial slits; jugular component slightly undulated anterior to first branchial slit, forming angular component of hyomandibular canal (ACH). Angular component contacts nasal (NAS) and supraorbital canals (SOC) through the infraorbital canal (IOC). Infraorbital canal projects posteriorly, forming a compact infraorbital loop (IOL), then curves medially. Infraorbital canal parallel to jugular canal (JUG), forming a concise posterior jugular loop (PJL). Suborbital component of infraorbital canal (SOI) long and slightly curved toward disc interior, presenting undulations, and connected to the prenasal component of nasal canal (PNC) on anterior disc. Posterior nasal loop (PNL) and nasal interior loop (NIL) small and set anterior to the nostril. Skeletal morphology. Neurocranium. Nasal capsules (NC) elongated, ventrolaterally expanded (Fig. 22). Anterior margin of nasal capsules oval and convex, with an internal ventromedial sept separating both capsules. Precerebral fontanelle (PCF) expanded and subcircular, posteriorly delimited by the epiphysial bar (EBP). Frontoparietal fontanelle (FPF) cone shaped, progressively narrowing, ending just posterior to postorbital processes. Both fontanellae together keyhole-shaped. Postorbital process (POP) long and narrow, diagonally projected anteriorly to level of angular cartilages. Prespiracular cartilage (PSC) posteriorly curved at its external margin. Jaws and hyomandibular arch. Hyomandibular arch (HYO) elongated and laterally projected (Figs. 22 b, c). Three angular cartilages present. Anterior angular cartilage (AAC) slightly concave, 1 / 3 length of hyomandibula, and laterally projected. Posterior angular cartilage (PAC) not concave, 2 / 3 length of anterior angular cartilage. Lateral angular cartilage (LAC) smaller, semicircular, positioned between the posterior angular cartilage and hyomandibula. Meckel's cartilage (MC) robust, with rectangular corners on internal surface, bearing a prominent and oval ventrolateral process (VTP) at its posterior margin, not contacting angular cartilages; lateroanterior process (LAP) robust. Palatoquadrate (PQ) also robust, with a small posterior concavity, limited at sides by a small triangular projection. Minute ligamental cartilage (LC) between both palatoquadrates, not fused to antimeres. Synarcual cartilage. (Fig. 22 a). Anterior synarcual articulates with neurocranium by a small but prominent odontoid process (OTP). Medial crest (MDC) extended over entire synarcual. Articular surfaces of scapular processes (ASP) laterally projected, separated by an accentuated concavity. Anterior articular surface more prominent then posterior surface; posterior surface more slender, its extremity acutely rounded. Pectoral girdle. (Fig. 22 d). Anterior process of the pectoral girdle more prominent, posterior process with a small, pointed extremity delimiting an adjacent concavity. Scapular process presents a slender medial bar, and its lateral portions present a well-developed central concavity, resembling an elongated " X ". A robust and elongated propterygium (PRO) anteriorly articulates to this process, as well as a small central mesopterygium (MES), and a posteriorly set and elongated metapterygium (MET). Pelvic girdle. (Fig. 22 e). Prepelvic process (PPP) projecting anteriorly to anteriormost third of metapterigium. Pubosquiadic bar (PIB) slender, with well developed and expanded extremities, bearing triangular lateral prepelvic processes (LPP) anteriorly. Iliac process (IP) robust, posterior to lateral prepelvic processes, with two round terminal expansions. Isquial process (ISP) slender, positioned medially. Four well-developed obturator foramina (OF) present between both processes. Clasper skeleton. (Fig. 23). Basal segment 1 (B 1) wider anteriorly, articulating with pelvic fins rays. Basal segment 2 (B 2) subcylindrical and with a ventral concavity. Both basal segments about equal in length, but segment 2 more slender. Axial cartilage (AX) elongated and cylindrical, about 3 / 4 clasper total length, and curved posteriorly. Ventral marginal cartilage (VM) diamond-shaped, ventrally curved. Beta cartilage (BE) slender and cylindrical, about 1 / 3 clasper total length, articulating with basal segment 1. Well developed and oval dorsal marginal cartilage (DM), about 2 / 5 clasper total length, slightly curved internally. Dorsal terminal 2 (DT 2) oval, curved interiorly, and projected dorsally. Terminal accessory cartilage (TA) suboval, presenting a narrow anterior margin, and posteriorly convoluted. Ventral terminal cartilage (VT) well developed, about 1 / 2 clasper total length, being the posteriormost robust element, with a posterior margin straight and ventrally curved, and anterior portion oval and dorsally curved. Geographic distribution. Potamotrygon adamastor is currently known only from rio Urariquera, a large right-bank tributary of rio Branco, Amazon Basin, state of Roraima, Brazil (Fig. 43).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817403B1CCDB6F95661F962E6.taxon	etymology	Etymology. Named after Adamastor, one of the giants of Greek mythology who opposed Zeus and Thetis and was thereby sent to Earth, acting as a raging storm over the Cape of Storms. The epithet adamastor is an adaptation of the Greek “ Adamastos ”, meaning untamed. A noun in apposition.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817403B1CCDB6F95661F962E6.taxon	materials_examined	Additional material. (5 specimens). MZUSP 104654 (adult male, 483 mm DW), rio Branco, rio Urariquera, municipal district of Boa Vista, upper Amazon Basin, state of Roraima, Brazil, 3 ° 22 ’ 51.9594 ” N, 60 ° 35 ’ 44.1594 ” W, February 2007, coll. M. R. de Carvalho et al.; MZUSP 104657 (adult female, 581 mm DW), same data as MZUSP 104654; MZUSP 104663 (adult female, 615 mm DW), same data as MZUSP 104654; MZUSP 115212 (2 neonates from MZUSP 104654).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817753B16CDB6FDFD6170604E.taxon	materials_examined	Holotype. MZUSP 117344 (adult male, 532 mm DW), rio Jutaí, municipal district of Boca do Titica, upper rio Amazonas Basin, state of Amazonas, Brazil, 2 ° 55 ’ 24.8 ” S, 66 ° 57 ’ 07.6 ” W, September 2012, coll. F. Marques et al. (Fig. 24). Paratypes. (2 specimens). MZUSP 117346 (adult female, 405 mm DW), same data as holotype (Fig. 25); MZUSP 117348 (adult male, 494 mm DW), same data as holotype.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817753B16CDB6FDFD6170604E.taxon	diagnosis	Diagnosis. Potamotrygon amazona sp. nov. is distinguished from congeners, except P. limai, P. scobina, P. garmani sp. nov., and P. adamastor sp. nov., by a combination of characters: disc relatively thick and robust, with a dark brownish to gray dorsal color, covered with numerous whitish to beige irregular spots, with small ocelli sometimes present; disc completely covered by denticles, with a high concentration of denticles on rostral portion of disc; rostral denticles simple, with a single central crown, and star-shaped basal plate; head denticles present star-shaped crowns, with a well-developed anterior dichotomy and small lateral dichotomies; caudal denticles with a central coronal plate and two anterior dichotomies, and a star-shaped basal plate; three angular cartilages of different sizes between jaw and hyomandibula; two to three irregular rows of thorns on dorsal tail midline, varying in size; tail long and robust, very prickly; tail base wide; cartilaginous rod relatively short. Potamotrygon amazona sp. nov. is further separated from P. limai by not having any polygonal pattern over disc, by having a wider tail (16.7 % DW vs. 14.8 % in P. limai), and by having simpler dermal denticles (smaller number and size of coronal ridges). From P. scobina and P. garmani sp. nov., P. amazona sp. nov. is distinguished by having a considerably more muscular disc, a more intense concentration of denticles on disc, dorsal color with many more spots, and a wider and shorter tail (mean tail width 14.9 % DW vs. 13.4 % DW in P. scobina and 14.1 % DW in P. garmani sp. nov.; mean tail length 86.1 % DW vs. 121.5 % DW in P. scobina and 100.6 % DW in P. garmani sp. nov.). Finally, P. amazona sp. nov. is separated from P. adamastor by having more dermal denticles on disc, greater number of dorsal spots forming clusters, and a longer tail (mean tail length 86.1 % DW vs. 78.1 % DW in P. adamastor).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817753B16CDB6FDFD6170604E.taxon	description	Description. Disc subcircular, longer than wide (DL 101.9 – 107.3 % DW) (Figs. 24, 25). Rostral portion of disc broadly convex, presenting a small rounded protuberance on snout (Fig. 26 a). Disc robust, dorsoventrally compressed, with comparatively thick margins. Eyes small and oval, around 3 times smaller than spiracles. Spiracles rhomboidal (Fig. 26 a), presenting a central internal papilla. Large and dorsally elevated head, up to 1 / 3 disc length, with interorbital distance 14.4 – 17.8 % DW, and interspiracular distance 15.4 – 18.3 % DW. Nasal curtains partially covering mouth, except at its margins. Mouth small and slightly convex, with a central notch (mouth width 8.5 – 10.2 % DW, and internasal distance 7.5 – 8.6 % DW) (Fig. 26 c). No labial ridges present. Five buccal papillae present, two posterior alternating with three anterior. Branchial basket wider than long, with space between first branchial slits 25.3 – 28.1 % DW, and distance between fifth branchial slits 17.4 – 18.9 % DW. Teeth small and numerous, wider than long, set in quincunx in a narrow arched upper tooth plate and a wide and trapezoidal lower tooth plate (Fig. 27). Tooth rows varying from 52 – 56 in upper jaw and 48 – 58 in lower jaw in males; single female specimen counted with 44 teeth in both jaws. Adult males present a single central pointed cusp on teeth in center of tooth plate. Lateral teeth in adult males, juvenile male examined, and female simple, presenting a single rounded cusp. Pelvic fins broad (length 54.3 – 64.9 % DW), subtriangular, with rounded corners and a slightly undulated posterior margin. Pelvic fin posterior margin barely projects beyond disc (Fig. 26 d). Length of anterior margins of pelvics 23.6 – 26.9 % DW. Claspers robust and cone shaped; clasper base much more robust and wider than its rounded tip; clasper external length 9.6 – 12.0 % DW and internal length 17.0 – 19.5 % DW. Clasper groove long, slightly curved, with a semicircular apopyle, at level of posterior tip of pelvic fins; hypopyle oval and large, subterminal, anterior to clasper flap. Dorsal pseudosiphon oval, obliquely positioned (Fig. 26 e). Tail robust and long, tail width 12.9 – 16.0 % DW. Tail tapers more intensely from caudal sting origin (Fig. 26 b). Cartilaginous rod short and robust, around 1 / 3 – 1 / 4 tail length. Caudal sting origin relatively close to tail origin. Tail with numerous lateral denticules, but without defined lateral spine rows. Small dorsal and ventral folds on tail extremity. Caudal stings well developed, their length 16.6 – 19.2 % DW. Coloration. (Fig. 28). Dorsal disc brownish gray to olive, with numerous small irregular spots from white to yellow, covering disc, sometimes with small ocelli (especially on disc margins), but these without a defined black contour. Two overall patterns apparent concerning spots and ocelli: 1) disc covered with small irregular whitish spots, smaller and more numerous on central disc, not forming definitive patterns; with small oval spots present on disc margins, smaller than eyes but larger than most irregular spots; 2) smaller irregular spots present, more spaced apart, forming semicircular or circular patterns, sometimes with ocelli at center. Spots progressively larger from disc center to margins. Dark streaks on head, synarcual, pectoral girdle and tail base present in both patterns. Ventral disc white to beige, sometimes with a darker central blotch. Larger specimens sometimes with darker pattern on lateroposterior disc margins, not anterior to central disc. Intensity of dark pigmentation increases with age and size. Pelvic fin dorsally with same color pattern as disc margin, with a slender lighter posterior margin. Ventrally, pelvic fins whitish with a posterior dark margin, varying with specimen size and age. Claspers also whitish but with darker gray blotches. Dorsal tail dark, similar to disc. Tail sides with small groups of small whitish irregular spots, without ocelli. White irregular blotches sometimes present between smaller spots. Ventral tail light with dark blotches, continuous with those of disc; whitish blotches interspersed with darker ones. Dermal denticles. (Fig. 29). Disc covered with dermal denticles, but more numerous and developed in three different regions. Rostral region presenting simple denticles, greatly varying in size (up to 3 – 4 times), with a single pointed crown. Basal plate (Bp) barely apparent, with asymmetrical basal ridges (Br) varying in number from 5 – 7. Rostral denticles arranged in a semicircular pattern on disc. Head and central disc with star-shaped pattern, presenting a developed central coronal plate (Cp), with two lateral posterior ridges and two converging anterior coronal ridges (Cr), these in two levels (Fig. 29 d). Single and double terminal dichotomies sometimes present. Basal plate poorly developed. Caudal region presenting a central well-developed coronal plate, curved posteriorly, with two anterior coronal ridges. Basal plate well developed, with 2 – 6 basal ridges. Two to three thorn rows on tail, varying in size, robust and curved posteriorly, with a marked basal plate. Ventral lateral-line canals. (Fig. 30). Hyomandibular canal (HYC) extends anteriorly from nostril, turning abruptly toward outer disc margins, extending parallel to anterior margin of disc. Anterior subpleural tubules not observed. Hyomandibular canal extends posteriorly as the subpleural component of hyomandibular canal (SPC), slightly undulated. Subpleural loop (SPL) deflects abruptly interiorly just anterior to level of pelvic fins; posterior subpleural tubules absent. Jugular component (JCH) projects anteriorly with a slight undulation towards branchial basket. Angular component of hyomandibular canal (ACH) runs external to branchial slits, and turns interiorly to the jugular canal (JUG) anterior to the branchial basket, reaching the posterior jugular loop (PJL). From this loop, the infraorbital canal (IOC) turns externally to form infraorbital loop (IOL). The infraorbital canal extends anteriorly, with slight undulations, curving toward disc center, forming the suborbital loop (SOL). Supraorbital canal (SOC) extends anteriorly from the anterior jugular loop (AJL). Orbitonasal component of supraorbital canal (CON) extends towards nostrils forming prenasal loop (PNL). Nasal canal (NAS) short and straight, directed toward mouth from anterior jugular loop. Prenasal component of nasal canal (PNC) extends towards anterior snout from anterior margin of nostrils. Measurements N Holotype Range Paratype Range Mean SD Skeletal morphology. Neurocranium. Nasal capsules (NC) ventrolaterally expanded, their anterior margin rounded, with an internal ventromedial sept in between (Fig. 31). Precerebral fontanelle (PCF) wide and subcircular, with straight anterior margins, posteriorly delimited by a subtriangular epiphysial bar (EBP). Frontoparietal fontanelle (FPF) subtriangular, narrowing posteriorly, extending to level of anterior margin of postorbital processes; fontanellae together keyhole-shaped. Postorbital processes (POP) prominent, long and narrow, projecting anterolaterally to posterior angular cartilage. Prespiracular cartilage (PSC) posteriorly curved. Jaws and hyomandibular arch. (Figs. 31 a, b). Hyomandibular arch (HYO) elongated and anterolaterally projected, slightly curved anteriorly. Three angular cartilages present. Anterior angular cartilage (AAC) slightly concave, about 1 / 5 – 1 / 4 length of hyomandibulae. Posterior angular cartilage (PAC) more straight, slightly smaller and more slender than anterior angular cartilage. Lateral angular cartilage (LAC) subcircular, between posterior angular cartilage and hyomandibula, about 1 / 4 – 1 / 3 length of posterior angular cartilage. Meckel's cartilage (MC) robust, internal margin with subretangular corners; its posterior margin bears a prominent ventrolateral process (VTP) not contacting angular cartilages, and a robust lateroanterior process (LAP). Palatoquadrate (PQ) smaller and more slender than Meckel's cartilage, presenting a small posterior concavity laterally limited by a small triangular projection. Small ligamentary cartilage (LC) present between palatoquadrate antimeres, not fused to antimeres. Synarcual cartilage. (Figs. 31 b, c). Anterior synarcual articulates with neurocranium by a central odontoid process (OTP). Medial crest (MDC) extends over entire synarcual. Articular surfaces of scapular processes (ASP) laterally projected, separated by concavity in between. Anterior articular surface rounded and more prominent then posterior surface; posterior surface with an acute extremity. Pectoral girdle. (Fig. 31 c). Anterior process of the pectoral girdle robust, posterior process with a small rounded extremity delimiting an adjacent concavity. Scapular processes with a slender medial bar, presenting a central concavity at anterior and posterior margins; lateral portions of scapular processes with a well developed central concavity. Propterygium (PRO) robust and elongated. Mesopterygium (MES) small and mesocondyle (MSC) elongated. Pelvic girdle. (Fig. 31 e). Prepelvic process (PPP) very elongated, almost reaching pectoral girdle. Pubosquiadic bar (PIB) slender, with expanded extremities. Lateral prepelvic processes (LPP) subtriangular, positioned anteriorly. Laterally positioned, robust iliac processes (IP) presenting a single round posterior expansion and a straight anterior one. Isquial processes (ISP) slender, set more medially, and projecting posteriorly. Four relatively large obturator foramina (OF) present. Clasper skeleton. (Figs. 31 d, 32). Basal segment 1 (B 1) with a wider anterior margin; both margins oval. Subcylindrical basal segment 2 (B 2) with a concavity on its ventral wall. Both basal segments about equal in length, but segment 2 more slender. Axial cartilage (AX) elongated, cylindrical and robust, curved posteriorly, narrowing toward extremity. Ventral marginal cartilage oval (VM), ventrally curved. Beta cartilage (BE) slender and cylindrical, slightly dorsally curved, articulating with the wall of basal segment 1. Dorsal marginal cartilage (DM) well developed and oval, about 1 / 4 of clasper length, curved medially. Dorsal terminal 2 (DT 2) oval, slightly slender and curved. Terminal accessory (TA) cartilage slender and straight, with a narrow, curved anterior margin. Ventral terminal cartilage (VT) well developed, about 1 / 3 of clasper length, being the most robust posterior element; ventral terminal with a triangular posterior portion, curved dorsally. Geographic distribution. Potamotrygon amazona is described primarily from the rio Jutaí basin, state of Amazonas, Brazil (Fig. 43), but other specimens identified as P. amazona are known from rio Branco (Roraima state) and rio Juruá. However, these localities may be innacurate, especially the latter as the specimens examined had poorly preserved tags and lack more precise locality information.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817753B16CDB6FDFD6170604E.taxon	etymology	Etymology. Potamotrygon amazona sp. nov. is named after the female warriors of Greek mythology, the Amazons, daughters of the god of war and goddess of harmony. Gender feminine.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A817753B16CDB6FDFD6170604E.taxon	materials_examined	Additional material. (6 specimens). MZUSP 117347 (adult male, 560 mm DW), rio Jutaí, municipal district of Boca do Titica, upper Amazon Basin, state of Amazonas, Brazil, 2 ° 55 ’ 24.8 ” S, 66 ° 57 ’ 07.6 ” W, September 2012, coll. F. Marques et al.; MZUSP 117345 (adult male, 584 mm DW), same data as 117347; INPA uncat. (“ no tag 1 ”) (juvenile male, 465 mm DW), rio Juruá, " Boca do Anaxaqui, Uacari "; INPA uncat. (“ no tag 2 ”) (adult male, 525 mm DW), same data as INPA “ no tag 1 ”; INPA uncat. (“ no tag 3 ”) (adult male, 531 mm DW), same data as INPA “ no tag 1 ”; INPA 7911 (adult male, 524 mm DW), rio Branco, municipal district of Comunidade Sacaí, state of Roraima, Brazil, 1 ° 23 ’ 46 ” S, 61 ° 50 ’ 40 " W.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	materials_examined	Holotype. UNT 2174 (adult? male, 341 mm DW), rio Paranã, municipal district of Paranã, affluent of rio Tocantins, rio Tocantins basin, state of Tocantins, Brazil, 12 ° 30 ’ S, 48 ° 12 ’ W, coll. staff of NEAMB. (Fig. 33) Paratypes. (3 specimens). UNT 2173 (subadult male, 405 mm DW), rio Santa Tereza, municipal district of Peixe, rio Tocantins, Tocantins basin, state of Tocantins, Brazil, 11 ° 48 ’ 7 ” S, 48 ° 38 ’ 21 ” W, coll. staff of NEAMB; UNT 2175 (subadult male, 350 mm DW), rio Tocantins, municipal district of Peixe, near the confluence with rio Santa Tereza, Tocantins basin, state of Tocantins, Brazil, 11 ° 47 ’ 27 ” S, 48 ° 37 ’ 2 ” W, coll. staff of NEAMB; UNT 2178 (adult female, 428 mm DW), same data as holotype (Fig. 34).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	diagnosis	Diagnosis. Potamotrygon garmani sp. nov. is distinguished from congeners, except P. limai, P. scobina, P. amazona and P. adamastor, by a combination of characters: disc dorsoventrally slender, with a light to dark brown dorsal color, and ocelli with beige, light yellow and whitish centers and a dark brown contour; ocelli mostly similar in size throughout disc but smaller ocelli sometimes present; small dermal denticles on central disc; disc margins usually without denticles; rostral denticles simple, with a single central cusp and a star-shaped basal plate; head denticles present star-shaped crowns, with one anterior and one posterior dichotomy lateral to the central cusp; caudal denticles present a central coronal plate and one anterior dichotomy; a third angular cartilage present; one or two irregular rows of thorns on dorsal tail midline, converging to a single row posteriorly; tail long and thin, with its base somewhat narrow; cartilaginous rod long, about same length as anterior portion of tail. Potamotrygon garmani sp. nov. is separated from P. limai by not having a reticulate or polygonal pattern on disc, by having a longer tail (100.6 % DW vs. 86.3 % in P. limai), and by having dermal denticles with fewer dichotomies and ridges. From P. amazona and P. adamastor by having a more slender disc, with less-developed disc musculature, smaller and fewer dermal denticles, greater and more defined ocellated spots on disc, and a more slender and longer tail (mean tail width 14.1 % DW vs. 19.0 % DW in P. adamastor and 16.7 % DW in P. amazona; mean tail length 100.6 % DW vs. 78.1 % DW in P. adamastor and 89.3 % DW in P. amazona). Finally, P. garmani sp. nov. is distinguished from P. scobina by presenting a brown disc, by having larger ocellated spots, tail shorter and wider (mean tail length 100.6 % DW vs. 121.5 % DW in P. scobina; mean tail width 14.1 % DW vs. 13.4 % DW in P. scobina), fewer teeth on both jaws (32 – 40 / 33 – 40 vs. 44 / 48 – 50 in P. scobina), and more thorns in dorsal mid-tail rows.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	description	Description. Disc subcircular, slightly longer than wide (its length 102.6 – 109.3 % DW) (Figs. 33, 34). Disc anterior margin convex, presenting a small round protuberance on snout (Fig. 35 a). Disc dorsoventrally compressed and slender, with comparatively thin margins. Eyes small and oval (mean 3.5 % DW), around two times smaller than spiracles; spiracles trapezoidal, obliquely set posterior to eyes (Fig. 35 a). Small and faintly elevated head, about 1 / 3 of disc length, with interorbital distance 13.8 – 18.6 % DW, and interspiracular distance 15.5 – 19.0 % DW (Fig. 35 a). Nasal curtain partially covering mouth, except at its margins. Mouth small and slightly undulated or convex, with a central notch (mouth width 8.6 – 10.2 % DW, internasal distance 7.7 – 9.3 % DW). Labial ridges absent (Fig. 35 c). Five buccal papillae present, two posterior alternating with three anterior. Branchial basket wider than long, with space between first branchial slits 23.2 – 24.9 % DW, and distance between fifth branchial slits 16.3 – 18.1 % DW. Teeth small, simple and rounded, wider than long, set in quincunx, in a narrow arched upper tooth plate and a wide and trapezoidal lower tooth plate (Fig. 36). Tooth rows varying from 32 – 40 in upper jaw and 33 – 40 in lower jaw. Adult males present a single central pointed cusp on central teeth of both jaws. Lateral teeth in adult males, teeth in juvenile males, and teeth in females simple, presenting a single rounded cusp. All teeth present a single cutting surface. Measurements N Holotype Range Paratype Range Mean SD Pelvic fins subtriangular, their length 48.0 – 61.1 % DW (mean 55.4 % DW), presenting round corners and an undulated posterior margin. Pelvic fin posterior margins slightly exposed posterior to disc (Fig. 35 d). Length of anterior margins of pelvic fins 19.6 – 25.7 % DW. Claspers robust and dorsoventrally compressed (Figs. 35 b, d, e). Clasper base much more robust than tip; clasper external length 9.6 – 11.7 % DW, and internal length 17.0 – 17.6 % DW. Clasper groove long, extending posteriorly in a straight manner, with a semicircular apopyle at level of posterior margin of pelvic fins, and an oval and large hypopyle, subterminal, positioned more externally. Dorsal pseudosiphon oval, set obliquely; ventral pseudosiphon slightly greater. Tail long and well developed, its width 11.9 – 16.4 % DW (mean 14.1 % DW), and length 71.0 – 115.2 % DW (mean 100.6 % DW) (Figs. 33, 34). Tail tapers posteriorly. Cartilaginous rod about 2 / 5 of total tail length, long and thin. Small and numerous denticles present, especially at origin of mid tail thorn rows. Tail also with lateral denticles in lateral spine rows as of sting origin. Caudal sting length 21.5 – 30.5 % DW. Coloration. (Fig. 37). Dorsal disc light to dark brown with numerous small, white to yellow irregular spots, on disc; beige to yellowish ocelli also present, circled by dark contours; spots regular in size and well highlighted, never greater than eye-size. Ocelli spread all over disc, usually without any defined pattern of spots around them, but small irregular whitish spots sometimes set around a “ central ” ocellus, more common on disc margins. Ocelli smaller at disc margins, progressively larger toward disc center. Ocelli also on tail base and dorsal pelvic fins. Spots vary in size and number on dorsal disc and between different specimens. Ventral disc white to beige, lacking enlarged central black spot. Subadults and adults with dark blotches on posterolateral disc margins, extending anteriorly to level of mouth. Larger specimens darker. Pelvic fin dorsal surface with same color of disc margins; posterior margin lighter. Ventrally, pelvic fins whitish with a posterior dark margin, darker in larger specimens. Dorsal claspers brownish, with irregular non-ocelllated spots. Claspers dark ventrally. Tail dorsally brownish, similar to disc, with small irregular light colored spots, smaller than ocelli. Laterally, tail with small groupings of small light colored irregular spots, without ocelli. Ventrally, tail covered by dark blotches, continuous with those of disc. Dark blotches progressively larger from posterior to anterior tail. Adult specimens may present a completely dark ventral tail. Dermal denticles. (Fig. 38). Disc totally covered with dermal denticles, but more numerous in three specific regions. Disc margins with smaller and fewer denticles. Rostral region with simple denticles, with a single pointed crown without coronal ridges (Cr). Larger disc denticles with a pair of oblique, posterior small protuberances (Fig. 38 b). Basal plate (Bp) low and barely apparent, with asymmetrical, robust basal ridges (Br), between 5 and 10 in number, coverging toward central cusp. Denticles of head and mid region of disc with star-shaped pattern, presenting a posteriorly oriented coronal plate (Cp), with two lateral posterior ridges that may present a terminal dichotomy, and two anteriorly converging robust and long coronal ridges (Cr), sometimes with an irregular surface; terminal dichotomies may be present. Lateral ridges smaller than anterior ones. Caudal region with a central well-developed coronal plate, curved posteriorly, with two well-developed anterior coronal ridges. These ridges may present a medial protuberance, creating a small discontinuation. Basal plate well developed and low, with many converging slender basal ridges. Two or three irregular thorn rows over tail base, with a single irregular thorn row over more distal tail anterior to caudal stings. Denticles present a robust, posteriorly oriented central cusp. Basal plate semicircular and varying in size and shape. Lateral spine rows sometimes present, composed of small denticles, originating at origin of caudal stings and extending posteriorly to tail tip. Ventral lateral-line canals. (Fig. 39). Hyomandibular canal (HYC) slightly undulated, projecting toward anterior disc from nostrils, deflecting toward outer disc margins; few short and straight subpleural tubules present (AST). Hyomandibular canal extends posteriorly as the subpleural component of the hyomandibular canal (SPC). Subpleural loop (SPL) relatively acute posteriorly, extending to level of pelvic fin origins. Posterior subpleural tubules not observed. Jugular component (JCH) projects anteriorly, slightly undulated, towards branchial basket. Angular component of hyomandibular canal (ACH) external to gill slits, not undulated, deflecting medially to form the jugular canal (JUG) anterior to first branchial slit, and forming the posterior jugular loop (PJL). From posterior jugular loop, infraorbital canal (IOC) extends externaly to form infraorbital loop (IOL). Infraorbital canal extends anteriorly, slightly undulated, and deflects medially parallel to hyomandibular canal. Suborbital loop (SOL) extends to posterior disc with few short undulations towards snout. Supraorbital canal (SOC) highly undulated, extending obliquely and anteroposteriorly lateral to mouth and nostrils. Orbitonasal component of supraorbital (CON) curves towards nostrils forming prenasal loop (PNL). Nasal canal (NAS) short and straight, directed toward mouth. Prenasal component of nasal canal (PNC) extends towards anterior snout from nostril. Skeletal morphology. Neurocranium. Nasal capsules (NC) ventrolaterally expanded (Fig. 40). Anterior margin of nasal capsules oval and convex, with an internal ventromedial sept dividing both capsules. Precerebral fontanelle (PCF) expanded and subcircular, with a straight anterior margin, posteriorly delimited by a subtriangular epiphysial bar (EBP). Frontoparietal fontanelle (FPF) triangular, progressively narrowing, with a round posterior margin at level of anterior margin of postorbital processes. Together, both fontanellae keyholeshaped. Postorbital processes (POP) prominent, long and narrow, diagonally projecting anterolaterally to posterior angular cartilage. Prespiracular cartilage (PSC) posteriorly curved. Jaws and hyomandibular arch. (Figs. 40 a, c). Hyomandibulae (HYO) elongated, anterolaterally projected, presenting a curved anterior margin. Three angular cartilages present. Anterior angular cartilage (AAC) slightly concave, around 1 / 5 – 1 / 4 length of hyomandibula. Posterior angular cartilage (PAC) more straight, slightly smaller and more slender than anterior angular cartilage. Lateral angular cartilage (LAC) subcircular, positioned between posterior angular cartilage and hyomandibula, and about 1 / 4 – 1 / 3 length of posterior angular cartilage. Meckel's cartilage (MC) robust, with subretangular corners on internal margin; posterior margin bears a prominent ventrolateral process (VTP), not contacting angular cartilages, and a robust anterolateral process (LAP). Palatoquadrate (PQ) smaller and more slender than Meckel's cartilage, presenting a small posterior concavity, laterally limited by a small triangular projection. Ligamentary cartilage (lc) very small, positioned between both palatequadrate antimeres. Synarcual cartilage. (Fig. 40 a). Anterior synarcual articulates with neurocranium by a central odontoid process (OTP). Medial crest (MDC) extended over entire synarcual. Articular surfaces of the scapular process (ASP) laterally projected, separated by concavity in between. The anterior articular surface is rounded and more prominent then the posterior surface, which presents an acute extremity. Pectoral girdle. (Fig. 40 a). Anterior scapular process more robust; posterior process presents a small round extremity delimiting an adjacent concavity. Scapular process with a slender medial bar, with a central concavity on anterior and posterior margins, and lateral portions with a well developed central concavity. Propterygium (PRO) robust and elongated, mesopterygium (MES) small and metapterygium (MET) posteriorly positioned and elongated. Pelvic girdle. (Fig. 4 b). Prepelvic process (PPP) elongated, anteriorly projected. Pubosquiadic bar (PIB) slender, with expanded extremities. Modest subtriangular lateral prepelvic processes (LPP), positioned anteriorly. Laterally set, robust iliac processes (IP), presenting one round posterior expansion and a straight anterior one. Isquial process (ISP) slender, medial, and projecting posteriorly. Four well developed obturator foramina (OF). Clasper skeleton. (Fig. 41). Basal segment 1 (B 1) with a wide anterior margin; both margins oval. Basal segment 2 (B 2) subcylindrical with a concavity on its ventral wall. Both basal segments about equal in length, but segment 2 more slender. Axial cartilage (AX) robust, elongated and cylindrical, curved posteriorly, narrowing towards tip. Ventral marginal cartilage (VM) oval, ventrally curved. Beta cartilage (BE) slender and cylindrical, slightly dorsally curved, articulating with basal segment 1. Dorsal marginal cartilage (DM) well developed and oval, about 1 / 4 total clasper length, curved medially. Dorsal terminal 2 (DT 2) oval, slender and curved. Terminal accessory cartilage (TA) slender and straight, presenting a narrow, curved anterior margin. Ventral terminal cartilage (VT) robust, about 1 / 3 clasper length, with a triangular posterior portion.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	materials_examined	Geographic distribution. Potamotrygon garmani is known from the mid to upper rio Tocantins basin (Fig. 43). Specimens were examined from five different localities (see material listed above).	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	etymology	Etymology. Named in honor of Samuel Walton Garman (1843 – 1927), an American naturalist who greatly contributed to the development of Zoology, especially Herpetology and Ichthyology, in the U. S. A. His works on sharks and rays remain among the most impressive and important contributions to the field. Garman coined the genus Potamotrygon, as well as the family Potamotrygonidae, and described five species of freshwater stingrays (three remain valid), including P. scobina.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
C55887A8177F3B09CDB6FC1F63CC61BB.taxon	materials_examined	Additional material. (10 specimens). UNT 2172 (juvenile male, 252 mm DW), same data as holotype; UNT 2173 (subadult male, 405 mm DW), rio Santa Tereza, municipal district of Peixe, rio Tocantins, Tocantins basin, state of Tocantins, Brazil, 11 ° 48 ’ 7 ” S, 48 ° 38 ’ 21 ” W, coll. staff of NEAMB; UNT 2176 (no size data), rio Tocantins, municipal district of Peixe, near the confluence with rio Santa Tereza, Tocantins basin, state of Tocantins, Brazil, 11 ° 47 ’ 27 ” S, 48 ° 37 ’ 2 ” W, coll. staff of NEAMB; UNT 2177 (no size data), same data as UNT 2176; UNT 2179 (subadult male, 362 mm DW), rio Tocantins, municipal district of Porto Nacional, Tocantins basin, state of Tocantins, Brazil, 10 ° 43 ’ 15 ” S, 48 ° 25 ’ 14 ” W, coll. staff of NEAMB; UNT 2185 (juvenile male, 273 mm DW), rio Tocantins, Tocantins basin, state of Tocantins, Brazil, coll. NEAMB; UNT 2184 (juvenile female, 226 mm DW), same data as UNT 2185; UNT 2186 (juvenile male, 276 mm DW), same data as UNT 2185; UNT 1211 (juvenile female, cleaned and stained), same data as UNT 2185; UNT uncat. (adult male, 404 mm DW), same data as UNT 2185.	en	João Pedro Fontenelle, Marcelo R. De Carvalho (2017): Systematic revision of the Potamotrygon scobina Garman, 1913 species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the description of three new freshwater stingray species from Brazil and comments on their distribution and biogeography. Zootaxa 4310 (1): 1-63, DOI: 10.11646/zootaxa.4310.1.1
