Is Chironius scurrulus part of the Trinidad herpetofauna?

In 1993 Dixon et al. reported on a specimen of Chironius scurrulus from Trinidad. The specimen, UMMZ 43965 is a juvenile that was collected by E. B. Williamson, an insect collector at the turn of the 20^th century (winter 1912). Wagler’s Sipo as it is sometimes called inhabits Brazil, SE Colombia, N Bolivia, Ecuador, Venezuela, E Peru, Trinidad, Guyana, Surinam, French Guiana according to the Reptile Database website, and probably has a type locality of Rio Japura, Brazil (based on comments in Kornacker 1999). Boos (2001) also reported this species as part of the Trinidad herpetofauna, following the previous authors.

The UMMZ specimen of Chironius scurrulus said to be from Trinidad

Recently I visited the UMMZ and examined the specimen of Chironius scurrulus, it is undoubtedly that species, but there is evidence to suggest it did not come from Trinidad.  Also collected by Williamson that winter on Trinidad were some Rhinella marina, Hypsiboas crepitans, Mannophryne trinitatis, and several specimens of the stream toad, Atelopus hoogmoedi. The last species is of course unknown from Trinidad – but it is known from Guyana, the other country visited by Williamson during the winter of 1912. Given the low probability of picking up the only known specimen of Chironius scurrulus and the only known specimens of Atelopus hoogmoedi from Trinidad on one trip, it seems likely that the specimens were instead collected in Guyana and at some point mislabeled as to their origins.

I would like to thank Greg Schneider at the UMMZ for searching the archives for information on these specimens, and to César Luis Barrio-Amorós, J. Roger Downie, and Joanna Smith for their perspectives into these records.

Citations

Boos, H.E.A. 2001. The snakes of Trinidad and Tobago. Texas A&M University Press, 270 pp.

Dixon, J. R., Wiest Jr, J. A., & Cei, J. M. 1993. Revision of the neotropical snake genus Chironius Fitzinger Serpentes, Colubridae. Torino: Museo regionale di scienze naturali.