COMPARED WITH mammals, living members of the crocodile clan have exceptionally boring dentition. From the slender-snouted gharials of India and the nocturnal caimans of South America to the saltwater behemoths of the South Pacific, crocodile teeth vary little in morphology. All are conical and pointed. Each tooth in an animal’s mouth is almost identical to its neighbours—as befits a group of that feed on a mixture of fish and the occasional careless beast that strays too close to the shore, or even into the water itself.
This predilection for pointed fangs is not, however, how it has always been. During the days of the dinosaurs, the Jurassic and Cretaceous periods, crocodile-clan members showed extraordinary dental diversity. Many of their teeth have proved so bizarre that some palaeontologists have theorised that, far from being carnivorous, these ancient species might have been eating plants. A study published this week in Current Biology, by Keegan Melstrom and Randall Irmis at the University of Utah, confirms this. It also suggests that herbivory evolved in the crocodile clan on several occasions.