These tiny, small-winged dinosaurs were likely worse than chickens at flying

The discovery of two tiny dinosaurs with bat-like wings a few years ago was a paleontologist’s dream. How flight evolved in birds is still trying to pin down, and a look at this early development of bat-like wings in dinosaurs might give us a clue.

But a team of researchers has now suggested that just because you have wings doesn’t necessarily mean you can actually fly well.

Yi Qi and Ambopteryx longibrachium are two types of theropod dinosaur that lived about 160 million years ago. Both had unusually elongated fingers and a membrane of skin that stretched between them, much like a bat’s wing.

This is a very different type of wing than the one that theropod dinosaurs use to fly – the dinosaurs that eventually became birds. And in contrast to them after only a few million years Yi and Ambopteryx extinct, which is the first clue that these unusual wings couldn’t keep up with the birds of the future.

However, weird wings in extinct creatures mean that several types of wings (and with it flight) have likely evolved over the years Yi and Ambopteryx ‚s Attempts were not the winning strategy.

But before you can write off Yi and Ambopteryx As a complete evolutionary error in flight, you need to know how good (or bad) the two species were in flight.

In 2015 when Yi It was found that one team of researchers suspected that the size of its wings and other flight characteristics could mean it was a gliding creature – however, it is unlike any other glider we know and its center of gravity might even have that Sliding difficult. We just weren’t sure.

A new study by researchers in the US and China has now examined the flight potential of Yi and Ambopteryx much more detailed and conclude that they really weren’t good at getting their little feet off the trees they lived in.

“With the help of laser-stimulated fluorescence imaging, we re-evaluate their anatomy and perform aerodynamic calculations that cover flight potential, other wing-based behaviors, and gliding abilities,” the team writes.

“We think, that Yi and Ambopteryx were likely tree-like, most likely had no form of powered flight, and had significant deficiencies in flutter-based locomotion and limited gliding abilities. ”

The team’s analysis of the fossils (Yi Picture below) was able to capture tiny details in soft tissue that you cannot see with normal light.

Fossil of Yi qi. Look how fluffy it is! (kmkmks / Flickr / CC BY SA 2.0)

Then the team modeled how the dinosaurs might have flown and adjusted for things like weight, wingspan, and muscle placement (all things that we can’t tell from just fossils).

The results were… overwhelming.

“You really can’t do a powered flight,” says the lead author, biologist Thomas Dececchi from Mount Marty University.

“They have to be given extremely generous guesses about how to flap their wings. Basically, you have to model them as the biggest bat, make them the lightest weight, hit them as fast as a really fast bird, and give them muscles higher than they probably should have exceeded that threshold. They could slide, but even their slide wasn’t great. ”

Soft tissue map of Yi Qi. (Dececchi et al., IScience, 2020)

According to Dececchi and his team’s model, we’re seeing flight skills that are significantly inferior to that of a chicken, perhaps even worse than the flightless New Zealand parrot Kakapo, which is also mostly limited to gliding down trees but can at least flap and control descent.

But although it’s a little sad for them Yi and AmbopteryxIt’s good news for us – the results show even more that dinosaurs evolved (or at least tried) to fly multiple times.

As the team points out, it should come as no surprise, given all kinds of bats, gliders, flying squirrels, and other planing or flying mammals.

“We propose that this group was an independent aerial colonization for non-avialan theropods. If so, it would represent at least two, but more likely three or more attempts at flight (both powered and gliding) by small Pennaraptoran theropods during the Mesozoic, “the team writes in its newspaper.

“Given the large number of independent glide occurrences within crown mammals, this should perhaps not be surprising, but it does create a more complex picture of the aerial ecosystem.”

It seems like some things don’t change much, even in a hundred million years.

The research was published in iScience.