Psammodynastidae

Psammodynastidae is a family of elapoid snakes containing a single genus, Psammodynastes, with two species, Psammodynastes pictus and Psammodynastes pulverulentus, commonly called mock vipers. Both species are native to tropical and subtropical Asia and are known to occur together in parts of Indonesia while using different habitats. They mimic true vipers, flattening the head and displaying a false fang during threat behavior, but are actually rear fanged snakes with weak venom suited to small prey. Phylogenetic study places them as an early diverging lineage within Elapoidea that split off in the early to middle Eocene, distinct from the African family they were once grouped with.