From ScienceDaily: Euchambersia was a dog-sized pre-mammalian reptile living 260 million years ago in a deadly South African environment:
Living in the Karoo, near Colesberg in South Africa, the Euchambersia developed a deep and circular fossa, just behind its canine teeth in the upper jaw, in which a deadly venomous cocktail was produced, and delivered directly into the mouth through a fine network of bony grooves and canals.
“This is the first evidence of the oldest venomous vertebrate ever found, and what is even more surprising is that it is not in a species that we expected it to be, ” says Dr Julien Benoit, researcher at the Bernard Price Institute for Palaeontological Research at the University of the Witwatersrand in South Africa.
“Today, snakes are notorious for their venomous bite, but their fossil record vanishes in the depth of geological times at about 167 million years ago, so, at 260 million years ago, the Euchambersia evolved venom more than a 100 million years before the very first snake was even born. ” Paper. (public access) – Julien Benoit, Luke A. Norton, Paul R. Manger, Bruce S. Rubidge. Reappraisal of the envenoming capacity of Euchambersia mirabilis (Therapsida, Therocephalia) using μCT-scanning techniques. PLOS ONE, 2017; 12 (2): e0172047 DOI: 10.1371/journal.pone.0172047 More.
The venom, which probably flowed directly into the animal’s mouth, is thought to have been used primarily for hunting.
The fact that venom might be useful to the animal does not really explain how it comes to have it. But we are learning a lot about how complex mechanisms develop much earlier than thought.
See also: Evolution appears to converge on goals—but in Darwinian terms, is that possible?
and
Stasis: Life goes on but evolution does not happen
Follow UD News at Twitter!