The colubroid snake family Homalopsidae contained 10 genera and 34 species of rear-fanged semi-aquatic and aquatic snakes in 1970 with the publication of Gyi's monograph. In 2007 Murphy had updated Gyi's work and the family held the same 10 genera with 37 species plus two genera with uncertain status (Anoplohydrus, Brachyorrhos). Molecular studies published in the first decade of the 21st century demonstrated that while the Homalopsidae is monophyletic, the species-rich genus Enhydris is polyphyletic. Molecular analysis also found Brachyorrhos to be the most basal member of the clade, confirming an earlier hypothesis that it was a fangless homalopsid. Subsequently, two other fangless genera of homalopsids were discovered. We revalidate the genera: Homalophis Peters, Hypsiscopus Fitzinger, Miralia Reuss, Phytolopsis Gray, and Raclitia Gray. Also, we describe five new genera for species lacking available names: Gyiophis, Kualatahan, Mintonophis, Sumatranus, and Subsessor. The new arrangement for homalopsid names resolves the problem of the formerly polyphyletic genus Enhydris. For all species, we provide a synonymy, information on types and type localities, a diagnosis, as well as remarks on taxonomic and nomenclatural problems and a dichotomous key. Recent evidence suggests homalopsids show high levels of endemism and cryptic speciation.
Keywords: aquatic snakes, mud snakes, Homalopsidae, terrestrial–aquatic transition, geographic distribution, taxonomy
John C. Murphy and Harold K. Voris. 2014. A Checklist and Key to the Homalopsid Snakes (Reptilia, Squamata, Serpentes), with the Description of New Genera. Fieldiana Life and Earth Sciences. 8 :1-43. doi: http://dx.doi.org/10.3158/2158-5520-14.8.1