The fossil of a small, deer-like mammal with unusual teeth has earned the name of “little monster.”
The little animal browsed on leaves and grasses in what’s now southwestern Wyoming about 50 million years ago, an early example of artiodactyl, the diverse order of hoofed animals that includes modern deer, pronghorn, and the petite Asian chevrotain.
But the newly found specimen “represents a dramatic departure” from early ungulates of the ancient West, according to Drs. Richard Stucky and Herbert Covert, who describe the find the Journal of Vertebrate Paleontology.
Namely, unlike other browsers of its time, it had unusually large teeth that were much broader, with wide ridges around the base of its molars and pointed protrusions called cusps rising along their sides.
Owing to the animal’s diminutive size but likely fearsome smile, the paleontologists named it Gagadon minimonstrum — a tribute to the self-applied nickname of Lady Gaga’s fans, “little monsters.” [Learn more about ancient tiny mammals: “Prehistoric Global Warming Caused Dwarfism in American Mammals, Fossils Show“]
Pop culture name-dropping aside, the newly identified genus adds important new insights into the evolution of mammals in the American West, Stucky and Covert write.
Though a few of Gagadon‘s toothy traits have been seen in fossil mammals in Europe and Asia, its combination of “unusual features” is unique, and new to the North American fossil record, they say.
Gagadon is a “surprising variant” among North American hoofed animals that “indicates a significant departure from the basic early [forms],” the duo writes.
The study of the new species and others like it, they add, “is a prime source for studying rapid evolutionary change of the artiodactyls during the early Eocene.”
Stucky, R., & Covert, H. (2014). A new genus and species of early Eocene (Ypresian) Artiodactyla (Mammalia), from Bitter Creek, Wyoming, U.S.A.
Journal of Vertebrate Paleontology, 34 (3), 731-736 DOI: 10.1080/02724634.2013.827580