Fossilised teeth reveals vegetarian diet of some ancient crocs
Can you imagine a vegetarian crocodile? Apparently, these creatures once roamed the earth in prehistoric times, according to a new study.
After examining fossilised teeth, scientists at the University of Utah have discovered that multiple ancient groups of crocodyliforms (a group that includes living and extinct relatives of crocodiles and alligators) were plant-eaters.
According to the press release issued by the university, these vegetarian crocodyliforms appeared early in the evolutionary history of the group, shortly after the end-Triassic mass extinction, and persisted till the end-Cretaceous mass extinction that killed off the dinosaurs.
The finding of the research was published in the June 27th issue of Current Biology.
The scientists were able to find out about the dietary habits of the crocodylians because the teeth of these carnivores are simple and conial while the teeth of the herbivores are more complex. After measuring 146 teeth from 16 different species of extinct crocodyliforms, they used quantitative dental measurements and other morphological features to reconstruct their diets.
They concluded that herbivory came about at least three times (and possibly six times) in Mesozoic crocodyliforms.
"Our work demonstrates that extinct crocodyliforms had an incredibly varied diet," said lead author Keegan Melstrom, a doctoral student at the university.
"Some were similar to living crocodylians and were primarily carnivorous, others were omnivores and still others likely specialised in plants. The herbivores lived on different continents at different times, some alongside mammals and mammal relatives, and others did not. This suggests that a herbivorous crocodyliform was successful in a variety of environments!" he added.
The team intends to continue with their research, to learn more about why the extinct relatives of crocodiles diversified so radically after one mass extinction but not another.