Atractus paulus

description

Description of the holotype. An adult female, SVL 830 mm, tail length 83 mm (9.1 % of total length); head distinct from body; head length 22.6 mm (2.7 % SVL); head width 19.8 mm (87.6 % head length); rostral-orbit distance 9.3 mm; nostril-orbit distance 6.8 mm; interorbital distance 10.9 mm; head rounded in lateral view; snout sub-acuminate in dorsal view, truncate in lateral view; canthus rostralis not conspicuous; rostral subtriangular in frontal view, 4.6 mm wide, 3.0 mm high, slightly visible in dorsal view; internasal 2.5 mm long, 2.30 mm wide; internasal suture sinistral with respect to prefrontal suture; prefrontal 6.1 mm long, 4.9 mm wide; supraocular subtrapezoidal, 4.5 mm long, 3.4 mm wide at broadest point; frontal pyramidal, 7.0 mm long, 5.9 mm wide; parietal 10.8 mm long, 7.1 mm wide; nasal entirely divided, nostril well-spaced into both pre- and postnasal; prenasal 2.4 mm high, 1.5 mm long; postnasal 2.6 mm high, 2.5 mm long; loreal 5.0 mm long, 1.9 mm high; second, third and fourth supralabials contacting loreal on left side; third to fifth supralabials contacting loreal on right side; eye diameter 2.9 mm; pupil rounded; two postoculars similar in height, being upper

A new species of groundsnake genus Atractus Wagler, 1828 (Serpentes, Dipsadidae) from the Peruvian Andes revealed by unequivocal morphological characters

diagnosis

Diagnosis. Atractus paulus can be distinguished from all congeners by the following combination of characters: (1) smooth dorsal scale rows 17 / 17 / 17 with apical pits near cloaca; (2) postoculars two; (3) loreal moderately long, contacting second to fourth supralabials; (4) temporal formula usually 1 + 2; (5) supralabials eight, fourth and fifth contacting eye; (6) infralabials eight, first four contacting chinshields; (7) maxillary teeth eight; (8) gular scale rows usually four; (9) preventrals four; (10) ventrals 166 - 167 in females, condition in males unknown; (11) subcaudals 26 in females, condition in males unknown; (12) in preservative, dorsum yellow ochre; (13) ventral surface of body mostly black with scattered inconspicuous cream marks in juveniles, uniform brown in adults; (14) maximum body size 830 mm SVL in females; (15) tail size moderately short in females (9.1 - 13.6 % SVL); (16) midbody diameter 18.0 - 27.3 mm (Figs 1 - 3).

A new species of groundsnake genus Atractus Wagler, 1828 (Serpentes, Dipsadidae) from the Peruvian Andes revealed by unequivocal morphological characters

distribution

Distribution and natural history. The new species is known from two close localities Alto Ihuamaca and El Chaupe, at elevations of 1641 - 2161 m in the northern portion of the Cordillera Occidental of the Andes, San Ignacio province, Cajamarca department, Peru (Fig. 8). Both localities are in agricultural areas with coffee plantations and pastures for cattle ranching with scattered small patches of montane forest and secondary vegetation. According to Passos et al. (2010), the adult female holotype was collected by day crossing a trail at the forest edge in an open area and the juvenile paratype inactive under a log near a coffee plantation. The holotype contained 12 eggs in the oviduct, measuring 30.4 - 36.3 mm (X = 33.7 mm) length and 14.516.3 mm (X = 15.5 mm) width (Passos et al. 2010).

A new species of groundsnake genus Atractus Wagler, 1828 (Serpentes, Dipsadidae) from the Peruvian Andes revealed by unequivocal morphological characters

etymology

Etymology. The species epithet " paulus " is a Latin word being patronym for our friend Paulo Gustavo Homem Passos. Dr. Paulo Passos has described more than 34 Atractus species, approximately one-fifth of the astonishing diversity of this complex genus. The Latin word " Paulus " also means " small " and thus, we also refer to the type series composed only by the holotype and paratype.

A new species of groundsnake genus Atractus Wagler, 1828 (Serpentes, Dipsadidae) from the Peruvian Andes revealed by unequivocal morphological characters