Fossil reveals Cretaceous drama of croc attacking flying reptile

Scientists and college students have interaction in fieldwork at Bonebed 10 in Dinosaur Provincial Park in Alberta, Canada, on this July 11, 2023, picture.
| Picture Credit score: Brian John Pickles/Reuters

About 76 million years in the past, a juvenile of one of many largest flying creatures within the earth’s historical past, known as Cryodrakon boreas, walked alongside a riverbank on a lush coastal plain and lowered its toothless beak to take a drink, unaware of hazard lurking on the water’s edge. Immediately, a big croc surged out of the water in an ambush and sank its enamel into the Cryodrakon’s neck.

That was life, and dying, within the Cretaceous Interval within the Canadian province of Alberta. Scientists have unearthed within the badlands of Alberta’s Dinosaur Provincial Park the fossilised neck bone of a younger Cryodrakon, a kind of flying reptile known as a pterosaur, which will have died in simply such a state of affairs.

The fossil, examined below a microscope and with micro-CT scans, has a conical puncture 4 mm broad that seems to be the chew mark of a crocodilian that both preyed on the Cryodrakon whereas alive or scavenged its physique after dying.

Adults of this pterosaur had wingspans of about 10 metres and stood as tall as a giraffe. The juvenile’s wingspan was about 2 metres.

The elongated neck bone, about two-thirds full, is 8 mm lengthy. The bone is skinny. A lot of its outer wall is lower than a bank card in thickness.

“Most crocodilians feed on the floor of the water and are ambush predators, and plenty of pterosaur species are regarded as tied to the water as effectively. Given this, if it was predation, it doubtless occurred as an ambush on the water floor,” mentioned paleontologist Caleb Brown of the Royal Tyrrell Museum of Palaeontology in Alberta, lead writer of the examine printed this week within the Journal of Paleontology.

“There are a number of explanation why a pterosaur could be on the water floor, together with ingesting and looking for meals itself,” Brown added.

Trendy crocs are each lively predators and scavengers.

“There isn’t a signal of therapeutic, so the wound both occurred on the time of dying throughout an assault or after the animal was already lifeless,” mentioned ecologist and examine co-author Brian Pickles of the College of Studying in England.

Cryodrakon rivaled Quetzalcoatlus, which additionally inhabited North America on the time, as the biggest of the pterosaurs, which have been cousins of the dinosaurs. Each had heads with massive toothless beaks, lengthy necks, and quick tails.

“They have been carnivorous, however researchers have disagreed as to their feeding technique, with options from carrion-feeding scavengers to aquatic probers to heron-like terrestrial stalkers,” Brown mentioned.

The researchers famous that the puncture mark doesn’t match the form of the enamel of dinosaur predators on this area on the time, such because the Tyrannosaurus kin Gorgosaurus and Daspletosaurus. As an alternative, it matched the form of a croc’s tooth.

Crocodilians dwelling on this ecosystem included Leidyosuchus, round 3.5 metres lengthy, and the smaller Albertochampsa. The semiaquatic superficially croc-like Champsosaurus additionally was current.