Pterosaurs were the fighter jets of the prehistoric ages they lived in – with wingspans reaching 33 feet or more, massive heads and huge tooth-lined jaws, they were the terror of the Mesozoic Era from the late Triassic to the end of the Cretaceous period. With that kind of size, they should have had nothing to fear … and yet, they did. A new study found that many pterosaurs were terrorized by an enemy of their own creation … baby pterosaurs.
“What really surprised me about this research is that the feeding ecology of these magnificent flying animals is more like that of crocodiles than of birds.”
In a University of Portsmouth press release announcing a new study published in Cretaceous Research, co-author Professor David Martill of the School of the Environment, Geography and Geosciences addresses the misconception that researchers have had about the demise of pterosaurs – that the smaller ones were replaced at the end of the Late Cretaceous Period by an up-and-coming new species … birds. Martill was part of a group under lead author Roy Smith digging for ten years in Morocco’s Sahara Desert that discovered over 400 specimens of pterosaurs in the Kem Kem Group of sandstone-based rocks along the Algeria–Morocco border. Then researchers had assumed that pterosaurs were made up diverse sizes and species living together like modern birds. However, the bones they found told a different story. (Photos here.)
“We’d found some really big pterosaur jaws and also specimens that looked like smaller jaws – about the size of a fingernail – but these tiny pterosaur remains could have just been the tips of big jaws so we had to do some rigorous testing to find out if they were from a small species or from tiny juveniles of large and giant pterosaurs.”
“We also examined the surface of the bones and found they had a rippled texture. This was further evidence they were the bones of immature individuals as mature pterosaur bones have an incredibly smooth surface once they are fully formed.”
What they found was one species of giant pterosaur that dominated the ecosystem the way crocodiles dominate a river – eating small prey as hatchlings, medium prey as juveniles and large prey as adults. What they had thought were the bones of smaller adults of a different species were actually big babies of the same giant pterosaur species. Where were the smaller species of pterosaurs?
“Recent findings have suggested that hatchling pterosaurs could fly soon after hatching so they were quickly independent.”
A different study earlier this year uncovered evidence that newly hatched giant pterosaurs could fly almost as soon as they emerged. That gave them an early advantage over small adults of other species who were slower and more cautious when it came to hunting. The end result was that the smaller species lost their food sources and habitats to the giant pterosaurs – thus, they were driven to extinction by their own kind, not by the feathered new kids on the block.
By the end of the Cretaceous Period, there were only giant pterosaurs, and they met their extinction with the Cretaceous–Paleogene event 66 million years ago. One species that survived was the ancestor of the modern crocodile. The study’s comparison of pterosaurs and crocodiles brings up a frightening thought – what if evolution had given crocs the ability to fly?
Sometimes it’s better to be thankful for what you have – even if it’s 20-foot terrestrial crocodiles.