Thursday, March 8, 2012

Velociraptor's last meal revealed

The bone of a large flying reptile has been found in the gut of a Velociraptor, sparking fresh discussion among palaeontologists.

Velociraptors have previously been described as "hyper predators".

However, scientists suggest this pterosaur was too large to be the Velociraptor's intended prey but could have been scavenged.

The findings are published in the journal Palaeogeography, Palaeoclimatology, and Palaeoecology.

An international team of scientists revealed the drama of 75 million years ago with a detailed analysis of the skeleton found in the Gobi desert, Mongolia.

"It would be difficult and probably even dangerous for the small theropod dinosaur to target a pterosaur with a wingspan of 2 metres or more, unless the pterosaur was already ill or injured," said co-author of the study Dr David Hone, from the University College Dublin, Ireland.

"So the pterosaur bone we've identified in the gut of the Velociraptor was most likely scavenged from a carcass rather than the result of a predatory kill."

Velociraptors were not much taller than domestic turkeys but were thought to be voracious predators.

A famous fossil unearthed in 1971 known as the "fighting dinosaurs" shows a Velociraptor and larger Protoceratops apparently locked in combat.

But evidence of feeding by theropod dinosaurs, such as Velociraptor or Tyrannosaurus rex, are scarce in the fossil record.

Continue reading the main story

Velociraptor facts

  • Velociraptors were made famous in the film 'Jurassic Park' although in reality they measured 50cm tall and recent research found they were at least partially covered in feathers
  • Velociraptor means 'swift seizer' and may have been capable of reaching speeds of 24mph
  • They were effective predators with an enlarged sickle-shaped claw on each hindfoot and rows of sharp teeth
  • Velociraptors would have existed around 71 million years ago during the Upper Cretaceous period
  • Fossils from two species of velociraptor are known; one was discovered in Mongolia and the other in China
Final feast

The 75mm-long pterosaur bone shard was found within the rib cage where the Velociraptor's gut would have been.

According to Dr Hone the contents of dinosaur's stomachs often elude scientists as they are rarely preserved.

"Gut contents are pretty rare and pterosaur bones are rather fragile and don't preserve well, so it is an unusual find."

In addition to proving that velociraptors took advantage of ailing animals, Dr Hone suggests that the evidence provides a further revelation: that small dinosaurs ate relatively large bones.

By analysing the bones, researchers also found out that the Velociraptor died shortly after feeding on the pterosaur.

The smooth surface of the reptile bones suggest it was not eroded by stomach acids and the team discovered the Velociraptor itself suffered from a broken rib.

"Pretty much all carnivores are both predators and scavengers as the situation dictates - actually getting evidence for that from the fossil record is rather hard [to get] though," said Dr Hone.

Source: http://www.bbc.co.uk/nature/17276531

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