by Greg Mayer
Last weekend, a new exhibit opened at the American Museum of Natural History in New York: “Pterosaurs: Flight in the Age of Dinosaurs“. The New York Times had a piece on the making of the exhibit last week, and today their museum critic, Edward Rothstein, weighs in with his take on the pterosaurs. We’ve had occasion to favorably note Rothstien’s reviews previously here at WEIT, and his conclusion is that the exhibit is well worth seeing.
He writes:
The exhibition is unusually compelling, given its directness and simplicity. In one sense, pterosaurs are quite familiar: Any image of the dinosaur age shows them ruling the skies. But as you work your way through this exhibition, they become confoundingly strange. Walking on wings! A fourth finger for flying! Crests larger than heads!
His review also considers how it is we come to know about the pterosaurs (‘pterosaur epistemology’), the serendipity of fossilization and discovery, and how small clues can be used to build up a more complete picture of the creature, noting, for example how a small mass of ejected bones (a gastric pellet), which might be overlooked, reveals what pterosaurs ate.
It reminds us of what exists before hypotheses accumulate, and what the paleontologist must accomplish, combining meticulous examination with speculative reconstruction. The pellet presents just a slightly more extreme version of how many pterosaur fossils are found. Some are seen here: jumbles of flattened bones and random filaments, gastric pellets spat out of some geological maw. …
Out of accidents, order takes shape; we see this to be as true of the paleontologist’s enterprise as it is of evolutionary change. The effect is to make us wonder which is more marvelous: the creatures themselves, or the ways they have been recreated?
The accompanying website is chock full of images, videos and information– go have a look. Here’s a nice summary video.
Some aspects of the reconstructions are speculative– we don’t really know what colors their crests were (although we do have evidence for the color of some Mesozoic reptiles). And, surprisingly to me, there is almost nothing about the “hairs”– called “pycnofibers”– that have been described in a number of pterosaurs. I’ve always thought the suggestion of pterosaurs being haired was very exciting, and, if true, a nice example of convergence, and evidence that pterosaurs were warm-blooded. The only mention I can find on the AMNH site concerns Jeholopterus, a small pterosaur with pycnofibers, seen in the following gif:
Pterosaurs are, of course, reptiles (and not dinosaurs!), and one of the three groups of tetrapods to have evolved true flight (as opposed to gliding, which has evolved many more times). Pterosaurs’ air foil is membranous skin, stretched along an enormously elongated 4th finger; bats, too, have a membranous wing, but it is supported by fingers 2 through 5; birds have a wing of feathers, which project not from elongated finger bones, but from a shortened and fused set of hand/finger bones. These structures are nicely illustrated in the following figure from Steve Gatesy and Kevin Middleton:
Powered flight is thus an excellent example of convergent evolution— the origin of similar structures as adaptations to similar conditions of existence. The wings, because they evolved independently, are said to be analogous (i.e. not derived from a common ancestor possessing wings), as is evident from the different nature of the air foil, and the different modifications of the bones involved in the wings of the three groups– the similarities are superficila nad functional. It also nicely shows the hierarchical nature of homology. The front limbs of bats, birds, and pterosaurs are homologous as limbs (i.e. derived from a common ancestor possessing front limbs), but not as wings. The common structures (humerus, radius, ulna, etc.) are homologous at the level of tetrapods, but the modifications of these structures as wings are separate evolutionary events.
The exhibit is temporary, and will be up through January 4, 2015. Be sure to put it on your list of things to see while in New York; it’s on mine!
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Gatesy, S.M. and K.M. Middleton. 2007 Skeletal adaptations for flight. pp. 269-283 in Hall, B.K., ed., Fins into Limbs: Evolution, Development, and Transformation. University of Chicago Press, Chicago.
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Keep the evolution posts coming! Having a downy covering, or ‘hairs’ of some sort makes sense for pterosaurs, since it can help them to regulate their body temperature more effectively.
Since we’re planning on going to NY in the summer, this is definitely an exhibition I want to take our son to (OK, I just want to go myself, but he digs dinosaurs, and pterosaurs, too).
I can’t figure out though when “Nauray 4, 2015” is 😉
Fixed– thanks!
GCM
I too had similar plans. We were going to take my son to some sort of ‘Pokemon store’ in NY but I think I will sort of get us lost…
I’d love to see this. Fascinating.
Now I just need to plot my way over to New York some time in the next few months.
I know – I will one day go to the New York Metropolitan Museum (which has a kouros statue I’d like to see) & The American Museum of Natural History! I could spend a whole vacation there (screw shopping!)
Go to a hardware store for that!
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Come to London! The British Museum has wonderful kouroi (and the Elgin Marbles)
🙂
Yeah I do have to see those (kouroi and marbles). I want to go to the museum in Berlin too that has the Pergamon Altar.
Is the title “Pterosaurs take Manhattan” a play on the Leonard Cohen song “First we take Manhattan”
…oops, sorry, that wasn’t supposed to inbed.
I think it’s the Rogers and Hart song ‘I’ll Take Manhattan’ made immortal by Ella Fitzgerald
You got there first!!
GCM
No, it was “I’ll Take Manhattan”, by Rodgers and Hart. Click on the link in the first mention of New York in the OP– it links to a video of the song.
GCM
And “The Daleks Take Manhattan”!
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And, um, the Muppets
http://www.imdb.com/title/tt0087755/
Nice succinct contrast of analogy and homology. I’m going to steal it for a lecture.
There’s a free iPad app, too!
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Cool! Installing now!
The first of three episodes of PBS “My Inner Fish” hosted by Neil Shubin was aired this week. Excellent. I’ve also order the book.
YES. It was great. I would rank it the best documentary that I have seen in a long time. Easy enough for the general public, technical enough to be educational for the rest. What I also appreciated was there were NO ERRORS (that I could see). This of course must have a lot to do with the fact that Neil Shubin did most of the talking.
I’ve recorded all of them. I had the flu all week and they were on here at 10pm which is past my bedtime. I hope to watch them this weekend.
There was a 1982 film called ‘Q’ about a pterodactyl nesting in the Chrysler Building, No idea if this is relevant or not . . .
‘Q’ for Quetzalcoatl’? That is the really huge pterosaur. Love that name.
Quetzalcoatlus is the pterosaur — otherwise we’re dealing with one of those imaginary things embedded in a religious context.
Going by the Boris Vallejo poster, not a pterosaur.
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True, it’s ‘Quetzacoatl, a winged serpent from Aztec mythology’ but still, I’m pretty sure the pterodactyl explanation comes up in the film
Maybe, but whoever that was can’t have been much of a biologist. I’ve just watched the trailer on YouTube and Q has six limbs (per the poster) and its wings have a bat-like bone structure!
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Yeah, yeah. But what about fangs? Does it have really big fangs?
Not especially.
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Any chance this will be a traveling exhibit? I’d love for it to make it’s way down here to Texas. The Houston Museum of Natural Science has already had Lucy and the Thermopolis specimen of Archaeopteryx. The Archaeopteryx exhibit also had several pterosaurs, but it would be cool to have an entire exhibit dedicated to them.
I spent a few minutes looking up pycnofibers, and this is the best I could come up with concerning known examples, from Ask a Biologist (with this answer being provided by David Hone):
It’s easy to find more info on Sordes and Jeholopterus, but I’d like to know what those other critters are.
Anyone interested in pterosaurs (especially azhdarchid pterosaurs) should check Tetrapod Zoology regularly. The link should take you to a page that itself links to several pterosaur posts.
Perhaps another evolutionary vestigial trait? While watching the Decorah eagles’ nestlings I am always struck by the fact that they use their front “limbs” a.k.a. wings, to get about in their nest before they are able to stand up reliably on their back limbs.
Check at 0:0:55 here: https://www.youtube.com/… watch?v=X0wH1EDMHhM