For nearly 150 million years, dinosaurs would have looked up and seen nothing but pterosaurs — some as small as paper airplanes, and others as large as F-16 fighter jets. For a long time, they dominated the skies, soaring on skin wings supported by long fingers of bone. But all that changed when that infamous asteroid rocketed to Earth and killed off 90 percent of life on the planet, say scientists in a PLoS Biology study published Tuesday.

Because there have been so few pterosaur fossils dating to the end of the Cretaceous period, scientists have been led to believe that pterosaur populations had been in serious decline leading up the asteroid’s impact 66 million years ago. In the new paper, however, scientists announced a game changer: newly excavated fossils belonging to six new species of pterosaurs in northern Morocco. This payload, dating to the Late Cretaceous, indicates pterosaurs were still thriving until their brutal extinction.

“This is a fabulous discovery of pterosaurs from Morocco — they tell us their amazing diversity while we thought them in decline,” announced paleontologist Nour-Eddine Jalil, who was not a co-author of this paper, in a statement released Monday by PLOS Biology. “The Moroccan phosphates are an open window on a key moment in the history of the Earth, one that shortly preceded the global crisis that swept away, among others, dinosaurs and marine reptiles.”

pterosaur fossils
Top: Mandine of the pterosaur, *Alcione elainus*. Bottom: Forearm bone of the giant pterosaur, *Arambourgiania*. 

Pterosaurs left behind no descendants and only a scattering of fossils. To be so large and yet still able to fly, pterosaurs had incredibly lightweight skeletons and thin-walled, hollow-tube-like bones. The resulting frames were like those of carbon-fiber racing bikes, but unfortunately they are so delicate that it’s been very difficult for paleontologists to find their remains. These new fossils are unique not only because they represent new species, but because of the sheer number of them.

These were found alongside fossils belonging to a previously discovered species, the Azhdarchidea, and likely represent three different families of pterosaurs, each ranging widely in size and skeletal proportions.

The large range of sizes demonstrated in this fossil group, which also show differences in beak shape and wing proportions, suggests that these pterosaurs occupied distinct ecological niches. Their wingspans ranged from 2 to 10 meters; at their maximum they were three times larger than the biggest currently living bird. The largest pterosaur fossils suggest the biggest boys could have weighed 400 pounds.

This haul suggests that there are likely many more pterosaur species waiting to be discovered.

“Exciting discoveries are being made all the time,” co-author and University of Portsmouth professor David Martill, Ph.D., announced in a statement, “and sometimes, just the smallest of bones can radically change our perception of the history of life on Earth.”


You’ve read that, now learn about this 99 million-year-old dinosaur fossil: