The genus Taricha use the poison tetrodotoxin (TTX) that binds and blocks voltage-gated sodium channels (Nav) in nerves and muscles.

There are species and sub-species of Taricha that live in concurrent regions with a garter snake (Thamnophis) that has developed a resistance to the TTX poisoning.

Species that inhabit regions with resistant Thamnophis snakes have evolved to increase their concentrations of TTX in an evolutionary arms race of predator versus prey.

Cladograms based on the work of Pyron and Wiens (2011)[4] and modified using Mikko Haaramo [5] †Archaeotriton basalticus Salamandrina Mertensiella caucasica Chioglossa lusitanica †Megalotriton filholi Lyciasalamandra Salamandra †Carpathotriton †Brachycormus noachicus †Chelotriton †Palaeopleurodeles hauffi Pleurodeles Echinotriton Tylototriton Notophthalmus Taricha †Koalliella genzeli †Oligosemia spinosa Lissotriton Neurergus Ommatotriton Calotriton Triturus Euproctus Ichthyosaura alpestris †Procynops miocenicus Laotriton laoensis Pachytriton Cynops Paramesotriton The genus Salamandrina is the only member of the subfamily Salamandrininae, and the genera Chioglossa, Lyciasalamandra, Mertensiella, and Salamandra are grouped in the subfamily Salamandrinae, with sixteen other genera comprising the subfamily Pleurodelinae.

[7] The sole known stem-salamandrid is Phosphotriton sigei, from the Quercy Phosphorites Formation, which apparently dates from the Middle to Late Eocene.