Fossil Shows First Saber-Toothed Mammals

New research reveals one of the first carnivores, a bobcat-sized carnivore that lived in what is now San Diego. Diegoaelurus vanvalkenburghae, a newly named species, and the genus are one of the earliest known Mammals obligate carnivores. The study was published in PeerJ.

Despite its feline-like look, this species lived during the Eocene epoch and was not closely related to felines. The study is co-authored by paleontologist Ashley Poust of the San Diego Natural History Museum, Diegoaelurus was a machaeroidine, an extinct species of meat-eating Mammals and the oldest group of saber-toothed creatures. The co-author also said that 42 million years ago, were only figuring out how to survive on meat alone. Then the significant advance was to evolve specialized teeth for slicing flesh, which we see in this newly described specimen.

In 1988, paleontologists discovered a lower jaw and a jumble of well-preserved teeth in the 42-million-year-old Santiago Formation in southern California. The fossil found near Oceanside during construction was researched briefly before being donated to the San Diego Natural History Museum. The specimen is the first machaeroidine discovered on the West Coast of the United States or in any North American region other than Utah and Wyoming. The discovery of machaeroidine fossils is significant because they are extremely uncommon.

The discovery sheds new light on the behavior, diet, and evolution of one of the world’s first Mammals hypercarnivores. This creature appeared 24 million years after all non-avian dinosaurs died out.For the first time, Poust and his colleagues were able to examine the relationships of these early Mammals carnivores. Scientists weren’t sure if numerous machaeroidine individuals lived at the same time before this investigation. It’s probable that they did because a significant member of this group, Apataelurus, lived in what is now eastern Utah about the same time.