Toxicofera

Toxicofera (Greek or Latin for "those who carry toxins"), is a hypothetical clade of living Squamata (lizards and snakes). It includes about 4600 living species. This is all venomous reptile species, plus related non-venomous species.
The clade was identified when research showed that the evolution of venom was very ancient, and that it might have occurred only once.
Cladistics.
The Toxicofera combines the following groups from traditional classification: