This is not good. A lot of prehistoric sci-fi movies (we’re looking at you — Jurassic Park franchise) may soon have to carry a disclaimer that “objects flying in mirror are not as bat-like as they appear.” New research on pterosaurs suggests that they didn’t fly with their legs spread apart like bats and every picture you’ve ever seen of pterosaurs in flight. Why? Because they’d crash and burn and go extinct far earlier than they did.
“Consequently, in the absence of extraordinary evidence to the contrary, our analysis casts doubt on the ‘batlike’ hip pose traditionally inferred for pterosaurs and basal maniraptorans, and underscores that reconstructions of joint mobility based on manipulations of bones alone can be misleading.”
That’s the conclusion of a new study authored by Armita Manafzadeh, a PhD student in the Department of Ecology and Evolutionary Biology at Brown University, and published this week in the Proceedings of the Royal Society B. Hidden in that concluding paragraph from the study is a hint to why pterosaurs didn’t fly like bats, but the real reason, according to a press release from Brown University, has to do with chickens Manafzadeh picked up while shopping.
“If you pick up a raw chicken at the grocery store and move its joints, you’ll reach a point where you’ll hear a pop. That’s the ligaments snapping. But if I handed you a chicken skeleton without the ligaments, you might think that its joints could do all kinds of crazy things. So the question is, if you were to dig up a fossil chicken, how would you think its joints could move, and how wrong would you be?”
Very wrong. In fact, as wrong as just about every paleontologist has been since 1801 when Georges Cuvier proposed that pterosaurs were not aquatic creatures with paddle-like appendages but flyers. Cuvier gave them the name “Ptero-dactyle” which stuck until so many variations were found that they became a family called pterosaurs. While paleontologists are good at finding bones, they’re not so hot at imagining the package they were in or what held them together, as Manafzadeh’s research found.
Using dead quail bodies, she removed the ligaments and then manipulated the bones in every possible way, recording the positions in 3-D. When the ligaments were attached, less than 5 percent of the movements were physically possible. Manafzadeh then attempted to simulate the flight method of bats – where the hind legs are spread wide because the wings are connected to them. She found again that this style would be physically impossible for pterosaurs with ligaments.
So, how did pterosaurs – some the size of modern-day giraffes – look when they were flying? Scary, but the 3-D modeling program used by Manafzadeh is designed to prove what can’t be done, not what can. For that, we’ll need a different model
Or a live pterosaur.
Source
No comments:
Post a Comment