Stories tagged pterosaur

Oct
03
2008

What on earth am I supposed to do with this thing?: A pterosaur considers his situation.
What on earth am I supposed to do with this thing?: A pterosaur considers his situation.Courtesy John Conway
Paleontology, y’all, paleontology. We’ve got these bones, these fossilized bones. And they’re nice bones, don’t get me wrong, but sometimes they leave a little to be desired when it comes to reconstructing the nitty gritty and sticky details of what living dinosaurs (and pterosaurs, ichthyosaurs, mosasaurs, therapsids, etc) were actually like. A skeleton can give us a good idea of a creature’s general shape; it can show where the muscles went (more or less), what sort of food it ate, how it probably moved—that kind of thing. But how did they behave? What color were they? Exactly how strong were they? There are a whole slew of questions that get to be a little tricky.

So, how do paleontologists go about answering these questions? They get creative, they study all the tiniest details of the fossils, and, sometimes, they look to living animals for analogy—that is to say, if an animal alive today that lives in a similar environment to that of an extinct animal, and has a similar body type to the extinct animal, you might be able to base knowledge of the extinct animal on what you know of the living animal.

It’s a valuable avenue of study, but dinosaurs and their ilk were pretty different, after all, so how far do you think can we take analogies to living creatures?

And now on to the news item.

A Japanese researcher has opened up his sass-box and gotten all up in the faces of paleontologists around the world. Pterosaur specialist paleontologists are particularly fired up, and they’re a dangerous bunch. “Peer review” among pterosaur specialists, as I understand it, involves switchblades, and the majority of the community sports eye-patches.

This scientist, Katsufumi Sato of the University of Tokyo, is saying that pterosaurs (all of the huge extinct flying reptiles) probably maybe couldn’t actually, you know… fly.

Oh no you di’en’t!

Says Sato: Yes, yes I did. Specifically, what the scientist did was place accelerometers on the wings of a couple dozen sea birds on the Crozet Islands. The accelerometers measured, more or less, the flapping force and speed of the birds’ wings.

Among the birds studied were wandering albatrosses, which have the largest wingspans of any living birds. Large seabirds like this have often been used as analogies for pterosaurs for their somewhat similar body shapes. Many pterosaurs probably lived in a similar habitat to modern seabirds as well.

Albatrosses fly by riding shifting wind currents, and by flapping their wings when the wind isn’t suitable, or is absent entirely. Sato found that the seabirds he studied have two flapping speeds, a faster speed for taking off, and a slower speed for staying aloft in the absence of wind. He also noticed that, as this flapping speed is limited by the birds’ strength, it decreases in heavier birds with longer wings.

According to the calculations Sato based off of this data, birds (or pterosaurs) weighing more than about 90 pounds would be unable to fly without using wind currents—they simply wouldn’t be able to flap their wings fast enough to stay in the air. There were certainly pterosaurs that size and much smaller, but a lot of flying reptiles were probably a great deal larger than that (a very conservative estimate for the quetzalcoatlus, for example, would have it weighing around 220 pounds).

The article I read on this research doesn’t get into Sato’s hypothesis much more than that, but I’d assume that this means that larger pterosaurs would then also be unable to take off from anywhere other than, say, a cliff face. I wonder if the implication is also that they wouldn’t be doing any flying at all; that medium to large pterosaurs wouldn’t even be gliding on wind currents because, at some point, they’d need to gain some altitude on their own steam.

But, whatever the specifics, them’s fightin’ words, and pterosaur specialists the world over are no doubt sharpening their boot-spikes, and wrapping their fists in chains.

Is it a valid analogy? Maaaaybeeee… But I’m betting against it. There have been some interesting theories lately about how the largest of the pterosaurs may not have flown as much as we used to think, but they don’t imply that they couldn’t fly at all. In fact, the study I’m thinking of would further distance pterosaurs from large seabirds in terms of behavior and their ecological niches (making any analogies a little less apt).

Other scientists argue that in addition to anatomical and physiological differences that should be considered, the atmosphere of the Mesozoic was, on the whole, somewhat denser, and had higher concentrations of oxygen—factors that would have allowed flight for larger, heavier animals. Actually, I recommend checking out the discussion following the article. There are a bunch of explanations of how pterosaurs could have flown, despite what this study suggests. But, if you do go, bring your knives—they’re an angry bunch.

May
28
2008

The world used to be so awesome and scary: Some quetzalcoatlus strut their way into my dreams.
The world used to be so awesome and scary: Some quetzalcoatlus strut their way into my dreams.Courtesy Matt Witton and Darren Naish
I’m all about pterosaurs. You should be too, really. I mean, eventually everyone will be into pterosaurs, and won’t it feel good to have boarded that train before it was cool? You’ll have, as it were, the best seat. You can be like, “Eh, whatever. I was into rhamphorynchoids when all y’all were poopin’ your pants over diplodocus.”

Pterodactyloids, obviously, are cooler than rhamphorynchoids, but you’re going to want to say “rhamphorynchoid” to prove what smoking hot Schmidt you really are.

Why are pterosaurs so cool? You probably already know, deep down, but please allow me to reemphasize, for my own sake.

Pterosaurs, as you all know, are extinct flying reptiles, like pterodactyls and pteranodons, right? They lived at the same time as the dinosaurs, and for about the same length of time as the dinosaurs (for about one hundred fifty million years), but they weren’t dinosaurs at all—if you can fly, you’re not a dinosaur, and pterosaurs definitely flew. Towards the end of the cretaceous, pterosaurs shared the skies with birds, but they weren’t birds either—pterosaurs evolved for flight long-before birds and independent of them (they were the first vertebrates to be able to fly). So, for millions upon millions of years, pterosaurs were the undisputed masters of the skies, and they evolved into all sorts of crazy forms. We can all picture pteranodons—pterosaurs twice the size of condors, with leathery wings and the big, pointy head crest—but pterosaurs came in a lot more flavors than that. Some were the size of pigeons, while others (like the SMM’s quetzalcoatlus) had wingspans easily exceeding thirty feet. Some, it seems, had adapted to live like flamingos do today, by scooping up mouthfuls of water, and filtering out food through more than a thousand straight, bristle-like teeth. Wild.

New research shows that some pterosaurs may also have specialized in hunting on the ground.

Initial reaction: Hey, you know what else specializes in hunting on the ground? Shrews. And you know what aren’t very cool? Shrews. Well, shrews are kind of cool, come to think of it, but they aren’t particularly impressive. So, an initial reaction follow-up: I don’t care about this. Herons and storks walk around and eat things out of the shallows. There’s nothing to be surprised about here.

Wrong. This stuff is rad. See, there probably were pterosaurs that hunted in shallow water like cranes, but that’s not what we’re dealing with here—these pterosaurs strolled around on the prairies looking for food. And, here’s the kicker, these aren’t little eagle-sized pterosaurs, these are the “azhdarchids,” the biggest of the big pterosaurs, with thirty-plus foot wingspans.

Hatzegopteryx: Keeping it real. Unfortunately, there were no people around when the azhdarchids were flying, but we provide good scale.
Hatzegopteryx: Keeping it real. Unfortunately, there were no people around when the azhdarchids were flying, but we provide good scale.Courtesy Mark P. Witton
Think about an animal the size of a plane landing in a field to chase down a fox-sized dinosaur, before snapping it up in a six-foot-long beak. Some of these pterosaurs would have been as tall as a giraffe. A flying, giraffe-sized, terrestrial predator. You have to admit, that’s super cool.

The prevailing theory (one still considered valid by many paleontologists) has been that these very large pterosaurs would have lived more like large seabirds do today—flying over lakes and oceans to grab fish from the water. This is probably a pretty accurate model for many pterosaurs, but further studies of azharchid skeletons and trackways (they left a lot of footprints around) indicate that their long limb bones, stiff necks, and relatively small, padded feet would have been well suited for stalking around on solid ground. Furthermore, about half of the azharchid fossils come from inland sediments (that is to say, places where there wasn’t a large body of water when the pterosaurs were alive).

I like this. I’m into this. Get on the boat with me. It’s called the S.S. Awesome, and we’re setting sail for the distant harbors of Hiptown.

UPDATE--One of the most recently discovered azhdarchids, the hatzegopteryx looks to be even bigger than the quetzalcoatlus, with a wingspan exceeding 40 feet. Also, it's head was almost two feet wide. That means it could have swallowed you whole, hotshot. I just thought people should know that.

Nov
15
2006

Two years ago, a scientist in Australia has a really lucky day. Tired after driving for several hours, he stopped to stretch his legs and -- boom! -- he tripped over a 100-million-year-old pterosaur jaw. (Pterosaurs were flying reptiles that lived at the same time as dinosaurs. The Science Museum has one hanging in our main lobby.) The jaw bone was encased in rock; after two years of careful preparation, the bone is finally free and can be studied by scientists.

(OK, so it wasn't a technically a dinosaur, and it was actually off to the side of the road, but c'mon, how often do I get to reference my favorite bad song of the Seventies?)