Chersodromus nigrum CANSECO-MÁRQUEZ, RAMÍREZ-GONZÁLEZ & CAMPBELL, 2018
Can you confirm these amateur observations of Chersodromus nigrum?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Chersodromus nigrum CANSECO-MÁRQUEZ, RAMÍREZ-GONZÁLEZ & CAMPBELL 2018|
Type locality: Xucayucan (19°53’47.9” N, 97°28’43.7” W; 1493 m asl), Municipality of Tlatlauquitepec, Puebla, Mexico
|Types||Holotype: MZFC 17619, adult male, (field no. ISZ 063), collected by Israel Solano Zavaleta on May 28 2005. Paratypes. UTA R-63417, Juvenile female (field number UOGV 062; Fig. 9 A) collected by Uri Omar García Vázquez on February 25 2002 at 5.5 km east from Tahitic (19° 55’ 33.9” N, 97° 31’ 42.4” W; 1530 m asl), Municipality of Zacapoaxtla, Puebla, Mexico; and an adult female MZFC 17661 (field number ISZ 059), same provenance as the holotype, obtained dead on road on May 27 2005.|
|Diagnosis||Diagnosis. Chersodromus nigrum can be distinguished from all Mexican species of snakes by having combination of prefrontals fused into single scale; postocular fused with supraocular; single anterior temporal present; dorsal scales keeled in 17 rows at midbody, unreduced posteriorly; supralabials 6, third and fourth entering orbit; infralabials 8, 1–5 contacting anterior chinshields); mental contacting anterior chinshields; venter mostly black.|
This species is characterized by its large size (260-315 mm SVL). It differs from Chersodromus rubriventris and C. australis by having fused supraocular and postocular scales; distinguished from C. australis and usually C. liebmanni by having first 5 or 6 infralabials in contact with anterior chinshield (vs. 4–5), further differing from C. liebmanni by having six supralabials (vs. seven) (Table 1 in Canseco-Márquez et al. 2018: 165).
|Etymology||The specific name is from Latin nigrum, meaning black, alluding at to the coloration of the dorsal and ventral surface.|
Sympatry: Diploglossus legnotus Campbell & Camarillo 1994, Scincella silvicola (Taylor 1937) and Geophis sp.