Breugnathair elgolensis — a species of hook-toothed lizard that lived during the Middle Jurassic, about 167 million years ago — displays a mosaic of anatomical traits that is not present in living groups, with head and body proportions similar to monitor lizards and snake-like features of the teeth and jaws, alongside primitive traits shared with early-diverging groups such as geckos.
Breugnathair elgolensis is one of the oldest relatively complete fossil lizards yet discovered.
The ancient reptile had snake-like jaws and hook-like, curved teeth similar to those of modern-day pythons, paired with the short body and fully-formed limbs of a lizard.
Nearly 41 cm (16 inches) long from head to tail, it was one of the largest lizards in its ecosystem, where it likely preyed on smaller lizards, early mammals, and other vertebrates, like young dinosaurs.
“Snakes are remarkable animals that evolved long, limbless bodies from lizard-like ancestors,” said Dr. Roger Benson, Macaulay curator in the Division of Paleontology at the American Museum of Natural History.
“Breugnathair elgolensis has snake-like features of the teeth and jaws, but in other ways, it is surprisingly primitive.”
“This might be telling us that snake ancestors were very different to what we expected, or it could instead be evidence that snake-like predatory habits evolved separately in a primitive, extinct group.”
