The colubroid snake family Homalopsidae contains 53 species in 14 genera. The family ranges from the Indus River of Pakistan eastward across India and Indochina into southern China, the Indonesian Archipelago, the Philippines, northern Australia and New Guinea, and one species occurs in Micronesia. While most are aquatic or semi-aquatic rear-fanged snakes, some lack fangs and are terrestrial. Since Bonaparte (1845) established the name Homalopsina, the composition of this taxon has been controversial. In one of the first molecular studies on snakes, Heise et al. (1995) found homalopsids to be basal to caenophidians. Kraus and Brown (1998) analyzed mitochondrial DNA and suggested homalopsids were the sister to the Southeast Asian Pareatidae. More recent molecular phylogenetic analyses established the Homalopsidae as a family distinct from the Colubridae, and supported its monophyly (e.g., Voris et al., 2002; Lawson et al., 2005; Alfaro et al., 2008). Other studies supported the Homalopsidae as the sister group to colubroids and elapoids (Kelly et al., 2003; Vidal & Hedges, 2005, 2009; Vidal et al., 2007; Wiens et al., 2008). Vidal et al. (2007) suggested the Homalopsidae be placed in the superfamily Homalopsoidea. Zaher et al. (2009) proposed the Endoglyptodonta (their clade 5) as a monophyletic group for the vipers, homalopsids, elapoids, and colubroids based on shared sulcate maxillary dentition. These recent molecular analyses suggested the crown homalopsids are of early Miocene origin (Alfaro et al., 2008) and that the family originated about 53.38 MYA (Pyron & Burbrink, 2012).
For more information see: Murphy JC, Voris HK. 2014. A checklist and key to the homalopsid snakes (Reptilia, Squamata, Serpentes), with the description of new genera. Fieldiana Life and Earth Sciences. 2014 Sep:1-43.