Conopsis Günther, 1858

Goyenechea, Irene & Flores-Villela, Oscar, 2006, Taxonomic summary of Conopsis, Günther, 1858 (Serpentes: Colubridae), Zootaxa 1271, pp. 1-27 : 2-3

Genus: Conopsis Günther, 1858

Conopsis Günther, 1858:6 . Type species Conopsis nasus .

Toluca Kennicott, 1859 . In Baird:23 Type species Toluca lineata .

Oxyrhina Jan, 1862:59 –60. Type species Oxyrhina varians .

Achyrhina Jan, 1862:61. Type species Achyrhina De Filippii= Toluca lineata Kennicott (no separate generic description).

Exorhina Jan, 1862: 61 . Type Species Exorhina maculata (no separate generic description).

Epirhina Jan, 1862:62–63. Type species Epirhina tessellata (no separate generic description).

Ogmius Cope,1869:162 . Type species Ogmius varians Jan. Proposed as substitute for Oxyrhina Jan , previously used.

Type species: Conopsis nasus ( Günther, 1858) Holotype BMNH lost, type locality “California”.

Neotype: BMNH 83.4.16.38, Milpas Durango ( Goyenechea and Flores­Villela, 2000).

Diagnosis: The genus Conopsis is comprised of viviparous snake species with burrowing habits. These snakes are relatively small, adults of all species ranging from 100 to 330 mm in snout­vent length SVL; and from 120 to 377 mm in total length TL; body subcylindrical; head short; snout pointed; pupil round; 17 rows of smooth scales at midbody; anal and caudal scales divided; 12 to 14 conic maxillary teeth, with a distinctive groove at least on the last tooth; two internasal scales; a preocular; two postoculars; a rostral ended in a tip; nasal scale pierced by the nostril; frontal scale hexagonal; temporal formula 1+2; 2.5 to 3 upper labials before eye; hemipenes subcylindrical, with reticulate ornamentation, and several large spines at the base. Prefrontals and internasals may be fused or divided; loreals may or may not be present (20% of sample examined); genial shields divided by a scale in 90% of specimens, but may be fused or divided by two scales. Upper labials 7, in 90% of the specimens (they vary from 5 to 7); lower labials 6 in 80% of the specimens (varying from 4 to 7). Ventral scales 120–127; subcaudals 29–39. Coloration and body markings vary considerably, both dorsal and ventral patterns. Dorsal pattern consists of dark spots, blotches or bands on a variable ground color, that goes from light brown, cinnamon, grayish, and olive green tones. Dorsal spots may be constituted from a series of hexagonal to elongated marks, a tessellated pattern, or lines along the body. Some snakes have no dorsal pattern of spots. There is less variation ventrally, generally the belly is yellowish, although it may be reddish or grayish. Ventral spots may be present in a series of central dots, large or small, medial, intercalated or paired, some acuta with black edged ventre.

The phylogenetic analysis (Goyenechea & Flores in prep.) suggests that Chionactis and Gyalopion may be the sister groups to Conopsis .

Chionactis differs from Conopsis in having a shovel­shaped snout with a deeply inserted lower jaw, genial shields separated by more than two scales, and 15 rows of scales at midbody.

Gyalopion differs from Conopsis in having a pentagonal frontal scale, the rostral upturned, dividing the internasals and prefrontals and contacting the frontal, and nasal partially fused with first upper labial.

Distribution: Conopsis is endemic to Mexico, ranging from Chihuahua to Oaxaca. Individuals occur mainly in pine and pine­oak forests, although they have also been collected in fir forests, xerophilous underbrush, submonte underbrush and caducipholious forest, between 1700 and 3200 m.