Fossilized Jaw remains of a rat-like specimen discovered at the Petrified Forest National Park in Arizona last year by a Virginia Tech College of Science Ph.D. c candidate turned out as the remains of a recently discovered 220-million-year-old species of cynodont, a stem-mammal, known precursor of current-day mammals.
The discovery of the new species, Kataigidodon venetus, was recently documented in the journal Biology Letters by primary author Ben Kligman, a doctoral student of the Department of Geosciences.
Kligman stated that the discovery of the species sheds light on the geography and environment during an early phase of mammals’ evolution.
“It also adds to evidence that humid climates played an important role in the early evolution of mammals and their closest relatives. Kataigidodon was living alongside dinosauromorphs and possibly early dinosaurs related to Coelophysis—a small bipedal predator—and Kataigidodon was possible prey to these early dinosaurs and other predators like crocodylomorphs, small coyote-like quadrupedal predators related to living crocodiles,” Kligman added.
He also mentioned that discovering a fossil part of Cynodontia, which contains close cousins of mammals, like the Kataigidodon, and some real mammals from the Triassic rocks, is an extremely rare happening.
Before Kligman’s discovery, the only other known cynodont fossil from the Late Triassic era in North America was a discovery of a braincase of Adelobasileus cromptoni in Texas from three decades ago.
About 220 million years ago, the geography of the world was a bit different. The modern-day Arizona and Texas were near the equator, close to the middle of Pangaea, the supercontinent.
Scientists expect that the Kataigidodon would have been living in such a lush tropical forest ecosystem.