Chironius sp.

Barrio-Amorós, César L. & Brewer-Carías, Charles, 2010, Venezuelan Guayana, with the description of five new species, Zootaxa 1942, pp. 1-68 : 52

Chironius sp.

Olive whipsnake, Cuaima machete

One juvenile female (EBRG 4169, field number L-1324) of 360 + 186 mm, with 185 ventrals, 168 paired subcaudals, 10 dorsals at midbody (12 on the anterior part of the body), and very prominent eyes. This specimen has some unusual characters that do not agree well with the description of C. fuscus (following Dixon et al. 1993). The first divergent character is the high number of ventrals (ventrals in the species range from 131–159 in males, and 140–160 in females), and also the high number of subcaudals, ranging in C. fuscus from 112– 140 in males and 105–140 in females. Also there are no distinguishable keels on the paravertebrals (this can be in the variation of C. fuscus ). There are no apical pits on the dorsal nuchal scales. The color for a juvenile is not typical for young C. fuscus , as it shows distinct light crossbands on a brown background, which changes ontogenetically. The coloration is more like an adult, uniform brownish above, and white ventrally; supralabials also white. Another unusual feature is a divided anal plate. Identification following the key of Dixon et al. (1993) identifies this specimen as C. grandisquamis , which is the only species with ten rows of dorsals at midbody and divided anal plate. However, C. grandisquamis distribution is Central American and Chocoan (from Honduras to northwestern Ecuador), and there is no geographic connection between those areas and the Guiana Shield. No other species in the shield region have these characteristics. Chironius scurrulus has ten dorsals at midbody and no keeling, but the anal plate is entire. Furthermore, juveniles are usually green in life and blue-black in preservative. This specimen may represent a new species or an aberrant C. fuscus . More animals from Sarisariñama must be examined in order to determine its final taxonomic status. The specimen had a recently metamorphosed hylid in its digestive tract, possibly Hypsiboas tepuianus .

McDiarmid and Donnelly (2005) report on a Chironius shed from Sarisariñama (probably collected by Orejas Miranda during the 1974 Expedition) .