Such large teeth are more often the mark of a meat-eating animal,
used to capture and kill prey.
The enormous canines probably were used by the plant-eating animals
to fight each other or protect against predators, said research leader Juan
Carlos Cisneros of the University of Piaui in northeastern Brazil.
For example, they might have fought for territory, resources or
females, like the modern musk deer, which also have a pair of large, tusklike teeth,
he said via email.
“These situations are extremely important for the survival of an
individual and the success of a species,” he said. Discovering animals like
this “shows us how nature is extremely creative in providing solutions for several
life tasks.” In addition to its saber shaped fangs, the newly discovered
animal, named , had rows of teeth on the roof of its
mouth for chewing, the researchers said. The lower jaw that was found was incomplete,
but they expect it would have had similar rows of teeth.
Tiarajudens was part of a group of animals known as anomodonts,
sometimes called “mammal-like reptiles” and a major plant-eater of their time.
The discovery provides novel insights into early tooth differences
in these ancient animals and the evolution of plant eating and its complex
social interactions, commented Joerg Froebisch of Humboldt University in
Berlin, who was not part of Cisneros' research team.
The evolution of saber teeth is exceedingly uncommon in plant-eating
animals, said Froebisch, calling the canines in the Brazilian anomodont “extraordinary.”
He said the animal seems to belong to a new, unusual group of anomodonts that
lived on the ancient southern supercontinent now called Gondwana. Before drift
formed the present continents, Gondwana included what is now Antarctica, South
America, Africa, Madagascar and Australia.
