Is there a palentologist in the house?
August 18, 2010 8:59 PM Subscribe
How much weight can a Pterodactyl/Pterosaur lift? Specifically something big like Quetzalcoatlus or Hatzegopteryx?
I blame twitter. The Fail Whale was up for a while today and I noted that there were only eight birds hefting the whale. (Yes, I know, there were other things I should have been doing, but work with me here.) I did the math and came up with each bird having to heft something in the neighborhood of 30,000 pounds (if the cartoon whale is something like 125 tons). Then I thought of pterosaurs (who doesn't?) and wondered how much weight they're capable of carrying.
Aside: I was heavily into paleontology in the 90s, went on multiple digs with a university team, did a documentary on it for grad school. But studied mainly sauropods and hadrosaurids, so I know only the basics about pterosaurs.
So far via google I've only found information that focuses on the ability of the pterosaur to fly (as in "can something this big fly at all or does it glide") rather than the ability of them to carry something while flying.
Yes, this train of thought started from pondering something deeply silly and yes, it's only a cartoon - but I'm now interested in pterosaurs and their ability to lift. And I do realize that while one could possibly lift a certain weight whether they could actually take off with that weight is an entirely different question. I think. I need to do more reading. While this all seems really speculative, I know that this kind of theorizing goes on in paleontology all the time - I'm just no longer up on where I should search for it and I'm now out of the loop of dinosaur research.
Short version: Can anyone point me to a website or text (can be offline) regarding pterosaurs and how much weight they can (theoretically) carry? Or have the name of a paleontologist that studies pterosaurs to recommend?
I blame twitter. The Fail Whale was up for a while today and I noted that there were only eight birds hefting the whale. (Yes, I know, there were other things I should have been doing, but work with me here.) I did the math and came up with each bird having to heft something in the neighborhood of 30,000 pounds (if the cartoon whale is something like 125 tons). Then I thought of pterosaurs (who doesn't?) and wondered how much weight they're capable of carrying.
Aside: I was heavily into paleontology in the 90s, went on multiple digs with a university team, did a documentary on it for grad school. But studied mainly sauropods and hadrosaurids, so I know only the basics about pterosaurs.
So far via google I've only found information that focuses on the ability of the pterosaur to fly (as in "can something this big fly at all or does it glide") rather than the ability of them to carry something while flying.
Yes, this train of thought started from pondering something deeply silly and yes, it's only a cartoon - but I'm now interested in pterosaurs and their ability to lift. And I do realize that while one could possibly lift a certain weight whether they could actually take off with that weight is an entirely different question. I think. I need to do more reading. While this all seems really speculative, I know that this kind of theorizing goes on in paleontology all the time - I'm just no longer up on where I should search for it and I'm now out of the loop of dinosaur research.
Short version: Can anyone point me to a website or text (can be offline) regarding pterosaurs and how much weight they can (theoretically) carry? Or have the name of a paleontologist that studies pterosaurs to recommend?
Response by poster: Metasyntactic - cool, thanks. If no one comes up with any specific articles/texts for me to turn to I'll start with his works, nicely cited on that link!
posted by batgrlHG at 9:09 PM on August 18, 2010
posted by batgrlHG at 9:09 PM on August 18, 2010
I have not much to add, unfortunately, but damn! I didn't know they were that big.
http://en.wikipedia.org/wiki/Dinosaur_size has some pretty interesting size comparisons.
I would assume that building wings is a pretty expensive exercise, and so they would only just be big enough to takeoff/fly. I imagine their weight/carrying capacity ratio would be similar to today's birds.
Find out what an eagle can carry, and multiply it up.
posted by antiquark at 9:46 PM on August 18, 2010
http://en.wikipedia.org/wiki/Dinosaur_size has some pretty interesting size comparisons.
I would assume that building wings is a pretty expensive exercise, and so they would only just be big enough to takeoff/fly. I imagine their weight/carrying capacity ratio would be similar to today's birds.
Find out what an eagle can carry, and multiply it up.
posted by antiquark at 9:46 PM on August 18, 2010
As I understand, larger birds (which may differ in their flight mechanics from pterosaurs), are generally not able to carry much extra weight. The heaviest flying birds today are the larger bustards and swan species - around 15-20kg. These birds don't typically carry materials as they fly, and reportedly the heaviest older individuals sometimes become so heavy they can no longer fly (that is, they are not able to successfully carry extra weight into the air). I have also heard that some larger species of vultures must disgorge a recent meal if they are forced to fly before they have had time to digest it (that is, once more, they can't carry extra weight into the air).
I only have a weak understanding of bird flight mechanics (classic work was done on this by Pennycuick) but I believe that models generally predict that birds are able to carry proportionally less extra weight as they increase in size. The models predict an upper limit to the weight of an animal which could fly. I'm curious to read Habib's articles and any others that get posted, to see how pterosaurs might have differed.
Also, you would have to factor in the size and shape of the object being carried. An object which was non-aerodynamic in shape would increase drag (air friction) on the bird as it flew, which would require that the bird exert even more power to keep aloft or could negatively affect its ability to soar.
posted by scrambles at 10:37 PM on August 18, 2010
I only have a weak understanding of bird flight mechanics (classic work was done on this by Pennycuick) but I believe that models generally predict that birds are able to carry proportionally less extra weight as they increase in size. The models predict an upper limit to the weight of an animal which could fly. I'm curious to read Habib's articles and any others that get posted, to see how pterosaurs might have differed.
Also, you would have to factor in the size and shape of the object being carried. An object which was non-aerodynamic in shape would increase drag (air friction) on the bird as it flew, which would require that the bird exert even more power to keep aloft or could negatively affect its ability to soar.
posted by scrambles at 10:37 PM on August 18, 2010
Find out what an eagle can carry, and multiply it up.
Not a useful exercise. Pterosaur wings were like bat wings. An eagle's wings are two-surface, which is more efficient.
More important, we don't really know how efficient the pterosaur respiration system was. Likely they were "warm blooded" but how well could they absorb oxygen and exhaust CO2? No one knows, and unless someone creates a time machine we probably won't ever know.
posted by Chocolate Pickle at 10:39 PM on August 18, 2010
Not a useful exercise. Pterosaur wings were like bat wings. An eagle's wings are two-surface, which is more efficient.
More important, we don't really know how efficient the pterosaur respiration system was. Likely they were "warm blooded" but how well could they absorb oxygen and exhaust CO2? No one knows, and unless someone creates a time machine we probably won't ever know.
posted by Chocolate Pickle at 10:39 PM on August 18, 2010
Another difference: in the Cretaceous the atmosphere wasn't the same as now. I've read that it is thought that there was a much higher proportion of oxygen in the air, for one thing, and that would critically affect the biomechanical calculations.
posted by Chocolate Pickle at 10:41 PM on August 18, 2010
posted by Chocolate Pickle at 10:41 PM on August 18, 2010
Someone posted a video on here at one point which showed a giant raptor in Europe carrying away a baby goat, but it was only able to glide "downhill" with it, with the aim of dropping it to kill it. That baby goat might be, what, 20-30 pounds?
I gather raptors are generally considered capable of carrying half their own weight in regular flight. In the case of an eagle which weighs 10 pounds, that means a 5 pound fish. An adult golden eagle weighs about 20 pounds with a wingspan of 7 feet when grande sized.
So my total half-assed conjecture is that a large ptero might be able to snatch something quite large and glide with it for a bit, assuming claw and wing muscle strength to hold onto it and keep its wings spread. But grab and go? With less efficient wings than birds probably not anything close to half its own weight, eh?
posted by maxwelton at 3:04 AM on August 19, 2010
I gather raptors are generally considered capable of carrying half their own weight in regular flight. In the case of an eagle which weighs 10 pounds, that means a 5 pound fish. An adult golden eagle weighs about 20 pounds with a wingspan of 7 feet when grande sized.
So my total half-assed conjecture is that a large ptero might be able to snatch something quite large and glide with it for a bit, assuming claw and wing muscle strength to hold onto it and keep its wings spread. But grab and go? With less efficient wings than birds probably not anything close to half its own weight, eh?
posted by maxwelton at 3:04 AM on August 19, 2010
As I understand, larger birds (which may differ in their flight mechanics from pterosaurs), are generally not able to carry much extra weight.
So are smaller birds more efficient in terms of the body mass to carrying capacity ratio? If this is correct, using a bunch of swallows is a better way to carry a whale rather than using a few pterodactyls, provided you can get them to coordinate.
Would this mean the twitter people actually got the details of scaling something to huge proportions right?
posted by Dr Dracator at 3:26 AM on August 19, 2010
So are smaller birds more efficient in terms of the body mass to carrying capacity ratio? If this is correct, using a bunch of swallows is a better way to carry a whale rather than using a few pterodactyls, provided you can get them to coordinate.
Would this mean the twitter people actually got the details of scaling something to huge proportions right?
posted by Dr Dracator at 3:26 AM on August 19, 2010
I have seen a video of an eagle hunting a goat in a mountain. The eagle seems to pick up the goat and lift it for short periods, but its mostly a controlled dive when they are attached.
I found it amazing because they were roughly the same size.
I bet you can still find that video in youtube.
posted by CautionToTheWind at 3:46 AM on August 19, 2010
I found it amazing because they were roughly the same size.
I bet you can still find that video in youtube.
posted by CautionToTheWind at 3:46 AM on August 19, 2010
Keep in mind also that flying by flapping flight is a different matter mechanically than soaring, gliding, and using up-drafts.
Also it takes more energy to take off from a sitting position on the ground or a tree branch with a certain amount of weight than to fly (flapping) at a slow steady speed with that weight. That is why some larger birds jump off of cliffs or trees or get a running start to take off.
posted by scrambles at 8:31 AM on August 19, 2010
Also it takes more energy to take off from a sitting position on the ground or a tree branch with a certain amount of weight than to fly (flapping) at a slow steady speed with that weight. That is why some larger birds jump off of cliffs or trees or get a running start to take off.
posted by scrambles at 8:31 AM on August 19, 2010
I don't think we're even sure if they flew. Some theorized they climbed cliffs and glided down. But you might want to check out the Haast's Eagle.
posted by chairface at 8:37 AM on August 19, 2010
posted by chairface at 8:37 AM on August 19, 2010
It also depends a lot on whether they have feet that can carry things. Raptors have feet that are very good at grabbing, holding, and carrying things, even heavy things. Swans (for instance), not so much. I don't know anything about pterosaur feet.
(Random cool fact: osprey feet are covered in a very bumpy, scratchy sort of skin that helps provide grip on a slippery fish; they also have one talon on each foot that can be rotated backwards or forwards, to further facilitate hanging on to the slippery fish, and especially the turning of it, so the fish faces forward while being carried.)
posted by rtha at 9:02 AM on August 19, 2010
(Random cool fact: osprey feet are covered in a very bumpy, scratchy sort of skin that helps provide grip on a slippery fish; they also have one talon on each foot that can be rotated backwards or forwards, to further facilitate hanging on to the slippery fish, and especially the turning of it, so the fish faces forward while being carried.)
posted by rtha at 9:02 AM on August 19, 2010
Birds often also carry objects in their beaks, pterosaurs probably could too.
posted by scrambles at 10:27 AM on August 19, 2010
posted by scrambles at 10:27 AM on August 19, 2010
This thread is closed to new comments.
link
He studies Pterosaur fossils and has concluded that not only did they actively fly but that they could launch from a standing position.
posted by Metasyntactic at 9:06 PM on August 18, 2010