Vegetarian crocodiles?

Recent research suggests that some species of crocodiles which were alive 200 million years ago were vegetarians. The study found that between three to six members of extinct crocodyliforms, which belong to the ancient crocodile and alligator family, had evolved teeth specialised for chewing plants including fruit.

To figure out what their diet consisted of, researchers compared the size and shape of teeth in extinct crocodiles versus the teeth of those around nowadays. They found that these extinct creatures possessed ‘complex teeth’, a significant trait of herbivores, in contrast to carnivores which possess ‘simple teeth’. The study author, Keegan Melstrom, a doctoral student at the University of Utah, suggests that ‘extinct crocodyliforms had an incredibly varied diet’, some being entirely plant-based whilst at least one other species of crocodile ate a mixed ‘omnivorous’ diet. This predominantly herbivorous strategy evolved on at least three separate occasions and appears to have been quite successful, suggesting that ‘an herbivorous crocodyliform was successful in a variety of environments’.

These types of crocodiles, which existed during the dinosaur age, ‘would have been killed off 66 million years ago in the end-Cretaceous mass extinction’. Today, all crocodiles alive possess relatively ‘simple teeth’, which are ideal for ripping apart and chewing meat.

Mr. Melstrom and other researchers now wish to better understand what reasons drew crocodiles at the time to diversify their diet and eating-habits so radically and how this compares to crocodiles nowadays.

Students interested in applying to Biological Sciences, particularly with interests in palaeontology, which is the branch of science concerned with fossil animals and plants, can reflect on these findings, and this type of evolution and surprising dietary adaption, considering questions on the topic such as why all species of crocodiles nowadays are meat-eaters. This may also be of potential interest to students planning on applying to Veterinary Medicine.