for National Geographic News
A hundred-million-year-old Brazilian fossil may offer rare evidence of an ancient encounter between a dinosaur predator and a flying reptile.
Massive carnivorous dinosaurs known as spinosaurs had snouts and jaws similar to modern fish-eating crocodiles. The similarity led many experts to believe that they were specialized hunters of fish.
Now a newly described fossil of a flying reptile called a pterosaur has been found to have a spinosaur tooth stuck in its spine. The discovery adds to the evidence that spinosaurs may have feasted on a wider variety of prey.
"It's very uncommon to find the tooth of a dinosaur actually embedded in the bones of its prey," said Eric Buffetaut, paleontologist with the Centre National de la Recherche Scientifique (CNRS) in Paris, France. Buffetaut is the lead researcher behind the find.
Buffetaut and his co-authors detail the find of three pterosaur vertebrae and the broken dinosaur tooth in tomorrow's edition of the science journal Nature. The remains are an unusual example of fossilized behavior, he said.
Sporting heads that looked similar to crocodiles' in a number of ways, spinosaurs were among the oddest of bipedal meat-eating dinosaurs.
"As opposed to a typical meat-eating dinosaur with thick, banana-shaped, blade-like teeth, spinosaurs all had long, narrow snouts with cone-shaped teeth," said paleontologist and expert on carnivorous dinosaurs Thomas R. Holtz, Jr., of the University of Maryland in College Park.
The first discovered spinosaur, Spinosaurus aegypticus, was named in 1915 after the long spines that protrude from each of its vertebrae. These spines would have formed a tall sail or crest.
But little more was known about spinosaurs until a string of more recent finds in the 1980s and 90s.
Since then researchers have speculated, based on the conical teeth and other features, that spinosaurs were specialized fish-eaters (perhaps preying on some similarly huge Cretaceous-period fish). Most crocodiles, which also sport conical teeth, include a large quantity of fish in their diet.
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