Atractus altagratiae

discussion

Remarks. Holotype (240 mm SVL) with prepared hemipenis kept inside a cryotube together with specimen. No tissue samples available.

Filling gaps between museum and society: An illustrated catalog of the primary type specimens of Squamata housed in the Museu Nacional, Rio de Janeiro, Brazil

materials_examined

Holotype. Adult male, MNRJ 7888, collected by Helmut Sick in July 1957 at Upper Cururú River (07 ° 12 ' S, 58 ° 04 ' W [approximate]; 127 m asl [approximate]), a tributary of the Teles Pires River, Municipality of Jacareacanga [Municipality of Itaituba and ca. 44 m asl as informed by the authors], State of Pará, Brazil.

Filling gaps between museum and society: An illustrated catalog of the primary type specimens of Squamata housed in the Museu Nacional, Rio de Janeiro, Brazil

description

Description of the holotype: Adult male, SVL 240 mm, TL 35 mm (14.6 % of SVL); head length 11.5 mm (4.8 % of SVL); body diameter 5.5 mm (2.3 % of SVL); head width 4.8 mm (42 % of head length); interorbital distance 4.0 mm; rostrorbital distance 3.3 mm (80 % interorbital distance); naso-orbital distance 2.5 mm; cervical constriction barely defined; head arched in lateral view, round in dorsal view; snout truncate in lateral view, round in dorsal view; rostral subtriangular, 2.4 mm wide, 0.9 mm high, barely visible in dorsal view; internasal 1.0 mm long, 0.7 mm wide; internasal suture sinstral with respect to prefrontal suture; prefrontal 2.3 mm long, 2.0 mm wide; supraocular subrectangular in dorsal view, 1.1 mm long, 0.6 mm wide; frontal subtriangular in dorsal view, 3.0 mm long, 2.8 mm wide; parietal 4.4 mm long, about twice as long as wide; nasal divided; nostril located between prenasal and postnasal; prenasal twice as high as long; postnasal similar in height to prenasal, slightly longer than high; loreal 2.6 long, 0.4 mm high; eye diameter 1.5 mm, pupil round; two postoculars; upper postocular taller (0.6 mm) and longer (0.4 mm) than lower postocular; temporals 1 + 2, first te

A new species of the colubrid snake genus Atractus (Reptilia: Serpentes) from the central Amazon of Brazil

diagnosis

Diagnosis: The single known male of Atractus altagratiae is distinguished from all congeners by the following combination of characters: (1) 17 / 17 / 17 dorsal scale rows, smooth, without apical pits, supranal tubercles, or keels; (2) two postoculars; (3) long loreal; (4) temporals 1 + 2; (5) seven supralabials, third and fourth contacting orbit; (6) seven infralabials, first four in contact with chinshields; (7) seven maxillary teeth; (8) three gular scale rows; (9) three preventrals; (10) 139 ventrals; (11) 27 subcaudals; (12) dorsal colour pattern uniform reddish brown, except the first two dorsal rows creamish white; (13) venter immaculate creamish white; (14) snout-vent length of 240 mm; (15) moderate tail size (14.6 % of SVL); (16) slightly bilobed, barely semicapitate, and semicalyculate hemipenis. Differs from all congeners except A. dunni, A. lasallei, A. lhemanni, and A. resplesdens in having 17 dorsal scale rows, seven supralabials, two postoculars, and dorsal colour pattern uniform reddish brown. Atractus altagratiae differs from these species in having the first two dorsal scale rows uniform creamish white, venter immaculate creamish white, and hemipenis slightly bilo

A new species of the colubrid snake genus Atractus (Reptilia: Serpentes) from the central Amazon of Brazil