Shocking! This Mammal Became Venomous About 100 Million Years Before Snakes Did
Researchers from the University of Witwatersrand found evidence that a small, dog-like, pre-mammalian reptile, Euchambersia, is the very first animal to produce and use venom.
Their discovery, described in a paper published in the journal PLOS One, showed that this mammal was able to turn their saliva into a venomous cocktail 100 million years before snakes did.
"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," explained Dr. Julien Benoit, a researcher at the Bernard Price Institute for Palaeontological Research at university, in a press release.
Benoit noted that the earliest evidence of snakes having venom dates back to 167 million years ago. On the other hand, the pre-mammalian reptile therapsid Euchambersia lived about 260 million years ago. This suggests that the Euchambersia has evolved to produce and use venom 100 million years before the very first snake was even born.
For the study, the researchers analyzed the only two fossilized skull of Euchambersia ever found. The fossils were found in 1932 and 1966. These fossils suggest that Euchambersia grew between 40 and 50 centimeters long and lived before the first dinosaur appeared.
Using cutting edge CT scans and 3D imagery, the researchers were able to find evidence of anatomical adaptations in the fossilized skulls. This adaptation is compatible with venom production.
The researchers observed a wide circular space in the animal's skull on the upper jaw that was connected to the canine and the mouth by a fine network of bony grooves and canals. Benoit and his team believed that the circular fossa on the jaw accommodates a venom gland.
Additionally, the researchers found teeth that were not yet described in the vicinity of the bones and rock. The teeth include two incisors with preserved crown and a pair of large canines. All the teeth that was found had sharp ridges.
Unlike the modern snakes that inject their venom using needle-like grooves in their teeth, the Euchambersia used its sharp ridges on the outside of its canine teeth. The venom of Euchambersia would flow directly into its mouth and will be passively injected to its victim through the ridges.