In the film Crocodile Dundee, the titular character reveals a huge scar he calls a “love bite” on his leg from when a crocodile tried to eat him. As shown by toothmarks on a pterosaur legbone, it seems crocodiles and their relatives have been giving such love bites for at least a hundred million years.
The bone is described in the journal Alcheringa and compared with another pterosaur femur found 355 kilometers (220 miles) away but dating from around 10 million years earlier. Despite the time between them, the two bones were remarkably similar – at least until a freshwater crocodylomorph took a bite out of one of them.
First author, Swinburne University PhD student Adele Pentland, told IFLScience it's impossible to tell if the crocodile bite occurred while the pterosaur was still alive, or if it represents postmortem scavenging. However, Pentland added, experienced paleontologists had assured her there was no way the pterosaur would have, Dundee-like, escaped and made its way to safety. “Once a crocodile got hold of you that was it,” she said.
It seems bites to the leg were something of an occupational hazard of being an Australian pterosaur. Twelve years ago, some of Pentland's co-authors were part of a study of the continent's sparse stock of flying reptile specimens, finding that one carried a series of marks apparently made by the teeth of an unidentified marine predator.
Not only is there some truth to the meme that everything in Australia is trying to kill you, but it's been that way for a long time. For creatures so dominant in the air, the danger came from the water.
With only a single bone to go on for each specimen, Pentland couldn't match either to a species. However, she and her co-authors conclude both belonged to the Anhangueria, a very widespread clade Pentland previously demonstrated survived long enough to include both of these specimens.
“It's really difficult to estimate wingspan from just legbones,” Pentland noted, “But from comparison we would say these might have had spans of 4 meters.”
It's astonishing that such creatures could take off from the water after catching fish, but other research has demonstrated it was indeed aerodynamically possible. Doing it with a crocodile hanging off your leg, however, would have been an entirely different matter.
A pair of isolated legbones is an exceptionally limited resource to study, but paleontologists who want to specialize in pterosaurs have to get used to making a lot out of a little. The light bones that allowed them to become the largest flying animals in Earth's history were fossilized very poorly. The problem is even worse for anyone working in Australia, whose lack of geological uplift has made fossils from the Jurassic and Cretaceous much harder to find than on other continents. For Pentland, the fact the bite marks provided rare ecological context was a lucky break.
Despite subtle differences, such as a small ridge on one side of one of the bones, the two femurs were remarkably similar given the differences in their ages. “It seems they were very stable,” Pentland told IFLScience. “There was not a lot of selective pressure on these parts of their anatomy.”