Evidence ancient shark took down flying dinosaur
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Scientists have discovered evidence of a prehistoric incident in which a shark leapt out of the water to take down a pterosaur while it was mid-flight.
The evidence is a fossil of one particularly unfortunate reptile which met a brutal end – judging by the shark tooth wedged against one of its vertebra.
Researchers from the University of Southern California discovered the tooth when studying bones at the Los Angeles County Natural History Museum.
Their study is published in the journal Peer J, and says the disfigured skeleton offers a window into the interactions of wildlife during the late Cretaceous period, between 66 and 100 million years ago.
Pterosaurs were flying reptiles with a wingspan of 18ft (more than five metres), and weighed about 100 pounds (45kg). In strict scientific terms they were not dinosaurs at all, but little is known about how they lived and behaved.
“Understanding the ecology of these animals is important to understanding life on Earth through time,” said the study’s senior author, Michael Habib.
Dr Habib, an assistant professor at USC, added: “Are there sharks today that hunt seabirds? Yes, there are.
“Is that unique or have big sharks been hunting flying creatures for millions of years? The answer is yes, they have. We now know sharks were hunting flying animals as long ago as 80 million years.”
As recently as 66 million years ago, North America was divided by a giant waterway called the Western Interior Seaway.
Stretching from the Gulf of Mexico to Canada, the remnants of the waterway today hold some of the world’s best fossils – especially in the Smoky Hill Chalk region of Kansas, where the shark-bitten pterosaur specimen was found.
The pterosaur was excavated in the 1960s and kept in storage at the museum before scientists plucked it from a display for further study.
According to the study, the shark tooth was a very interesting find. Of more than 1,100 specimens of Pteranodon, the species of pterosaur, only seven, or less than 1%, show evidence of interactions with predators.
The team had to rule out that the tooth wasn’t randomly stuck to the vertebra, but actually wedged between the ridges – clear evidence of a bite.
They tracked the tooth to a species known as Cretoxyrhina mantelli, an 8ft (2.4m) long shark which was relatively common at the time and comparable in appearance and behaviour to today’s great white sharks, although they’re not closely related.
The study also had to figure out how the evidence of the attack was preserved, as typically the powerful shark bites would have completely shattered pterosaur bones.
According to the study, the tooth just happened to get stuck on a particularly bony part of the neck – offering the rare opportunity for this fossil to be created.
“We know big sharks ate pterosaurs, so we could say a big fast predatory species could very well have eaten this Pteranodon when it entered the water, but we’ll probably never know exactly,” Dr Habib said.