Angry Vegetarian Saber-toothed Mammals Were Fighters Not Lovers

An artist's rendering of two members of Tiarajudens eccentricus family fighting. University of the Witwatersrand (South Africa)
An artist's rendering of two members of Tiarajudens eccentricus family fighting. University of the Witwatersrand (South Africa)

Can you believe this long-toothed prehistoric animal only ate grass? So what were those two sharp saber teeth for?

Tiarajudens eccentricus, a mammalian forerunner that lived 270 million years ago, was the one with these long, pointy teeth, researchers in Brazil and South Africa have found. It offers the oldest evidence yet of vegetarian animals using teeth to fight among themselves. It's similar to the combat we see among some modern species of deer, which were descended from T eccentricus. The findings suggest that as more herbivores evolved on the planet, they found more ways to do combat. And why was that?


"We think the main cause was the notable increase of herbivore diversity that happened during the middle Permian [period]," paleontologist Juan Carlos Cisneros, the study's lead author, wrote in an email. "Competition among herbivores, especially males, is important to establish access to resources, territory and females."

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The skull of a modern deer shows two long incisors teeth.
University of the Witwatersrand (South Africa)

Several herbivores and a few carnivores first appeared in the Permian period. Cisneros calls the period “a fascinating time in Earth's history, with the continents coming together to form Pangea and weird land creatures that had some modern-looking habits but lived long before dinosaurs." T. eccentricus was one of those weird creatures. Partial remains of one were found in 2011 in a layer of sandstone in Brazil.

T. eccentricus was about the size of a big dog and had a short snout. The wide teeth lining the roof of its mouth were good for processing high-fiber food, which is how scientists know it ate plants. It also wielded an impressive set of teeth. Long and sharp, the teeth may have looked fragile, the researchers wrote, but with an extra-strong internal structure, a root that nearly reached the top of its skull and a protective layer of enamel, they were reliable weapons.

These crazy teeth could be used to inflict painful scrapes on each other's necks or flanks — a means of wild combat that preceded the dinosaurs. The presence of the sabers indicates that that some behaviors practiced by modern ruminants are older than scientists knew, said Cisneros, who's based at the Federal University of Piauí, in Teresina, Brazil.