Modern crocodiles had ancient vegetarian cousins who roamed the planet 200 million years ago.
Dental fossils discovered between three and six members of the crocodile and alligator family had specialized teeth for chewing plants.
Researcher reconstructed her vegetarian diet by analyzing the fossils of 1
Many of their "complex" teeth were shaped differently than all modern herbivores, until the herbivores were extinguished 66 million years ago along with the dinosaurs.
Study author Keegan Melstrom, Ph.D. student at the University of Utah, USA, said, "The most interesting thing we discovered was how frequently extinct crocodile forms ate plants.
" Carnivores have simple teeth, herbivores have much more complex teeth ,
"Omnivores, organisms that eat both plant and animal matter, fall somewhere in between.
"Our study shows that complex-formed teeth that we suspect are herbivorous are found in extinct relatives of crocodiles at least three times, and perhaps even six times."
"Part of my previous research has shown that this Fall is The pattern applies to live reptiles with teeth such as crocodiles and lizards.
"These results have shown us that the basic pattern between diet and teeth is found in both mammals and reptiles, despite very different tooth shapes." Extinct reptiles. "
All crocodiles living today have a similar body shape with relatively simple, conical teeth that are ideal for their semi-aquatic lifestyle as carnivores.
However, the dental fossils in the study were clearly not carnivorous and seemed to have special forms that are not found in today's animals.
Mr. Melstrom and dr. Randall Irmis, chief curator of paleontology at the Natural History Museum of Utah, USA, compared the tooth complexity of extinct crocodiles with those of living animals to find out what they ate.
They used an originally used method developed for live mammals – measuring tooth size and morphological characteristics with a resolution of 25 data lines per tooth.
Mr. Melstrom said that the unexpected variety of teeth from crocodiles shows that they can thrive in a wider range of environmental environments than previously thought.
He also noted that the herbivores emerged soon after the end of the evolutionary history of the family – Triassic mass extinction about 200 million years ago.
They existed until the end of the Cretaceous, killing all dinosaurs except birds.
Fossil analysis suggested that between three and six species developed herbivorous food during the Mesozoic era.
Mr. Melstrom said, "Our work shows that extinct crocodile forms had an incredibly varied diet."
"Some resembled live crocodiles and were primarily carnivorous, others were omnivores, and others were probably specialized in plants.
"The herbivores continued to live on different continents at different times, some beside mammals and mammalian relatives, others not."
"This suggests that a herbivorous crocodile form was successful in a variety of environments."
He planned to further reconstruct the diet of extinct crocodiles, even in fossilized species that lack teeth.
The researcher also wanted to understand why the extinct relatives of crocodiles so radically diversified after a mass extinction, but not those who killed the dinosaurs – and Whether nutritional ecology could have played a role.
The study by the University of Utah and the National History Museum of Utah in the US was published in the journal Curr Biology.