Nature introduces a little guy who’s upending the way we think about the age of dinosaurs… a time when pterosaurs ruled the skies with 10-meter wingspans. Well, except there might in fact have been more pterosaurs around that were about the size of a pelican:
The fossils — an upper arm bone and vertebrae discovered on Hornby Island in British Columbia — came from a nearly full grown pterosaur that had a wingspan of just 1.5 metres and was about as tall as a housecat, scientists report on 31 August in Royal Society Open Science.
“It’s quite different from other animals we’ve studied. There hasn’t really been evidence before of small pterosaurs at this time period,” says Elizabeth Martin-Silverstone, the study’s lead author and a palaeobiologist at the University of Southampton, UK.
Study co-author Mark Witton, a palaeontologist at the University of Portsmouth, UK, acknowledges the work’s limitations. “We’ve only got one data point, so don’t rewrite the textbooks yet,” he says.
But he and his colleagues say that they carefully ruled out alternative explanations for the small size of the fossilized bones. The fused backbone means that the bones did not come from a bird. And it could not be a nyctosaur, a previously known small marine pterosaur, because the arm bone lacked that creature’s distinctive hatchet-shaped crest, where the flight muscles attach, says Martin-Silverstone.
The Cretaceous ended 66 million years ago with a mass extinction that saw pterosaurs vanish alongside the dinosaurs.
In general, the extinction wiped out bigger species, while smaller animals like many birds managed to muddle through and survive. If the latest finding is confirmed, it will turn out that birds were not the only small-winged vertebrates living then, although the tiny pterosaur’s unfortunate fate would imply that being little was no guarantee of survival.