Discovery Ground Snake

description

Description of holotype. Adult male, SVL 284 mm, tail length 28 mm (9.9 % SVL); body diameter 7.8 mm; head length 8.8 mm (3.1 % SVL); head width 5.6 mm (2.0 % SVL); interocular distance 3.4 mm; head slightly distinct from body; snout-orbit distance 3.4 mm; rostral 1.6 mm wide, ca. as broad as high; internasals 0.9 mm wide; prefrontals 2.1 mm wide; frontal 2.9 mm wide, with a curvilinear triangular shape in dorsal view; parietals 2.2 mm wide, ~ 2 x as long as wide; nasal divided; loreal 2.0 mm long, ~ 3 x longer than high; eye diameter 1.1 mm; pupil round; supraoculars 1.3 mm wide; one postocular; temporals 1 + 2, upper posterior temporal elongate; eight supralabials, fourth and fifth contacting orbit; symphysial 1.0 mm wide, ~ 2 x as broad as long and separated from chinshields by first pair of infralabials; seven infralabials, first four contacting chinshields; chinshields ~ 2 x as long as broad, posterior chinshields absent; four rows of gular scales; dorsal scales arranged in 17 / 17 / 17 rows, smooth without apical pits; two preventrals; ventrals 168; anal plate single; 27 paired subcaudals.

Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach

description

Figs 3, 4, 5 d Proposed standard english name: Discovery Ground Snake. Proposed standard spanish name: Culebra tierrera de Discovery.

Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach

diagnosis

Diagnosis. Atractus discovery sp. nov. is placed in the genus Atractus, as diagnosed by Savage (1960), based on phylogenetic evidence (Fig. 1). The species is diagnosed based on the following combination of characters: (1) 17 / 17 / 17 smooth dorsals; (2) one postocular; (3) loreal 2.5 - 3 x longer than high; (4) temporals 1 + 2; (5) eight supralabials, fourth and fifth contacting orbit; (6) seven infralabials, first four contacting chinshields; (7) six or seven maxillary teeth; (8) one row of gular scales; (9) three preventrals; (10) 168 ventrals in the male holotype (Fig. 3 b) and 170 - 172 ventrals in females; (11) 27 subcaudals in the male holotype and 17 - 18 subcaudals in females; (12) dorsal ground color light brown with faint stippling of a darker shade (Figs 3 a, 5 d); (13) venter yellow with a brown ventral stripe (Fig. 3 b); (14) 284 mm SVL in the male holotype and 308 - 328 mm SVL in females; (15) 28 mm TL in the male holotype and 19 - 24 mm TL in females.

Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach

distribution

Distribution. Atractus discovery sp. nov. is known only from two localities (Arena-les and Amaluza, listed under Suppl. material 1: Table S 1) on each side of the Rio Paute, in the Ecuadorian provinces Azuay and Morona Santiago, at elevations 2002 - 2057 m a. s. l. The airline distance between the two localities is 2.6 km (Fig. 2).

Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach