Mathematical models let Dececchi and the others plug in different sizes for the dinosaurs’ weight and wingspan, as well as try various wing shapes and muscle configuration. Based on their findings, they conclude that neither species was likely able to take off from the ground. While they have plausible ranges of body and wing size for gliding, they were probably pretty mediocre at it.
Compared to other animals that glide with the greatest of ease, the dinosaurs would need to be faster and leap from higher points to stay in flight. That makes it harder to land safely.
“If you’re going to be flying fast into a tree, it increases the chance you’re going to hurt yourself when you crash,” Dececchi told Popular Science. That inelegance, paired with legs not well-suited for running, could’ve contributed to these dinosaurs’ downfall, as better fliers, like Archaeopteryx, started competing for resources.
If Yi and Ambopteryx hadn’t gone extinct, they may have evolved to become better fliers. Pterosaurs started off clumsy but improved over millions of years. That’s according to a new study, published in Nature, from the University of Reading. Dr. Chris Venditti and the team used fossil remains of pterosaurs and metabolic rates of birds to estimate how far the reptiles could fly or glide before needing to stop.
Pterosaurs aren’t dinosaurs, but they did overlap with some of them. The winged lizards — what many of us grew up calling pterodactyls — are a group of around 200 known species. They started flying millions of years before birds and bats. Their membranous wings are more similar to bats and Yi and Ambopteryx than they are to birds.
Around 230 million years ago, the pterosaurs resembled the bat-like dinosaurs Yi and Ambopteryx. “They may have been climbing up trees and flying from one trunk to another, but not flying very long distances and not very agile in their flight,” Venditti told The Guardian.
With no other competitors in the sky, however, pterosaurs had time to work on these issues, and “pterosaur flight efficiency improved by 50% over the period from 230 million years ago to their extinction 66 million years ago,” according to Michael J. Benton, a professor of vertebrate palaeontology at the University of Bristol, who worked on the study.
The two studies together each shed light on the evolution of flight, even if the pterosaurs ended up more successful for longer than the flying dinosaurs.
“I think people assume that flying magically bursts onto the scene, but there’s a big energetic hill to overcome in order to fly,” said Venditti of the pterosaurs.
Even as animals did gain the ability to fly, not all of them were as successful and there’s not necessarily a straight line you can draw between one extinct species and today’s birds. Professor Hans Larsson of McGill University's Redpath Museum, who worked on the study of Yi and Ambopteryx, told the CBC that paleontologists are confident that birds are modern dinosaurs. “What this new study brings in, though, is that it’s not a clearcut, single trajectory going into birds,” he said.For more dinosaur news, read about the T. rex fossil that was recently sold for $31.8 million and what scientists opinions are after extracting DNA from insects that were preserved in resin – basically Jurassic Park come to life. Jenny McGrath is a science writer for IGN. She never tweets, but here she is @JennyMcGeez.