Pterosaur Tails

[stargatedalek]

Yesterday a friend and I had an interesting discussion about the uses of pterosaur tails, and why the drastic change of Rhamphorhynchoidea to Pterodactyloidea took place. I theorized that the long tails of Rhamphorhynchoidea could have evolved to help maintain brief periods of vertically oriented flight. Whether for hovering over shoals of fish or landing on vertical surfaces such as trees the long tail could have given them that extra bit of agility necessary. With some later species retaining these characteristic tails as species identification.

[Plasticbeast95]

It is interesting that Pterosaura "lost" their tails during the course of their evolution. Perhaps it corresponds to with a change in flight dynamics? Perhaps the tailless Pterosaurs relied more on maneuverability, it should be noted that Pterodactyloids have the wing supported more by the arm, in contrast to the  Rhamphorhynchoids, where the finger takes up a larger role in the wing frame. Perhaps a more arm-supported wing and stumpy tail are of great importance to maneuverability at lower speeds?

Of course this is just speculation.

[Dilopho]

Yesterday a friend and I had an interesting discussion about the uses of pterosaur tails, and why the drastic change of Rhamphorhynchoidea to Pterodactyloidea took place. I theorized that the long tails of Rhamphorhynchoidea could have evolved to help maintain brief periods of vertically oriented flight. Whether for hovering over shoals of fish or landing on vertical surfaces such as trees the long tail could have given them that extra bit of agility necessary. With some later species retaining these characteristic tails as species identification.

Maybe they were for display....maybe they were "rudders", which would have helped them turn directions fast!
I imagine the larger, tail-less pterosaurs like Pteranodon didn't do much agile flying. If the smaller ones flew like thrushes, the bigger ones flew like Albatross. Or, that's my opinion.

[Dinoguy2]

All good hypotheses. It also might have something to do with changing setup in the wing membrane between the legs, and the more upright walking style of pterodactyloids.

[reinier zwanink]

The tail and its loss are i my opinion very simple
Forerunner of these animals had to be ground animals who mostly all have a tail
The step to flight (and glide) pressed the need for wings first and the loss of the tail later for far better mobilety

A simular evolution took place with birds

[stargatedalek]

The tail and its loss are i my opinion very simple
Forerunner of these animals had to be ground animals who mostly all have a tail
The step to flight (and glide) pressed the need for wings first and the loss of the tail later for far better mobilety

A simular evolution took place with birds

While a good theory initially on paper, it doesn't account for the various changes in tail morphology before the tail was lost, or that pterosaurs took a lot longer than birds to shrink them.

[reinier zwanink]

Yes its a theorie like many have
And that ok
It is strange thou that to date the do not have a single pterosaur predecesor

[Lanthanotus]

It is strange thou that to date the do not have a single pterosaur predecesor

Not that strange when you take in account the locality in which the predecessor most likely lived/developed: a densely forested environment. Those areas naturally offer no good conditions to fossilize bones, especially not of such small and fragile animals as this most likely was.

One might say "but we also have fossils of those small and fragile pterosaurs", but that would neglect the fact that these flying animals could make use of their skill in more or less any environment, near shores, in open land, wooded areas, or in pelagic environments while the predecessor (most likely an animal developing a flight membrane for gliding from trees down) could make only use of it's new skill in such a specific environment.

However I'm pretty sure one day in the near future a strong evidence for this specific creature (or as Wittons names it: the HyPtA) will be found.

[Halichoeres]

It might seem like a facile observation, but it's striking that all three vertebrate groups that evolved powered flight lost at least the bony part of the tail in time. To me that suggests that there might be a trade-off in having a tail that outweighs its benefits on a long enough time horizon. They're expensive to make, they're relatively easy for a predator to grab, and if your flight ability depends crucially on its presence, losing it is lethal. That said, tailed pterosaurs coexisted with pterodactyloids for something like 40 million years, so there must have at least sometimes been some pressure to maintain the tail. And maybe the decline of "rhamphorhynchoids" had more to do with bird-line theropods than with derived pterosaurs. I don't know enough about the paleoecology to offer a conjecture. Still, striking that birds went to a pygostyle, bats reduced the tail to nearly nothing (with yes, some minor exceptions), and the last 50 million years' worth of pterosaurs were also tailless. Taillessness is probably a lot more versatile in terms of adjusting aspect ratio and colonizing new habitats. I'm tempted to think that at least some pterosaur tails were encumbrances maintained by sexual selection, though of course I have nothing to back that up.

[laticauda]

Bony tails might add a little extra weight, so it might just be more efficient without it during flight.

[Plasticbeast95]

Bony tails might add a little extra weight, so it might just be more efficient without it during flight.

Well, Pterosaurs were the master of weight reduction, they had air sacs in their arms.

[Balaur]

I read Mark Witton's pterosaur book, and apparently the vanes on the tails of the long tailed early pterosaurs are likely not very useful as rudders, so Mark came to the conclusion that they were used as sexual display structures. So, in order so that they didn't need a long tail (for weight purposes or for general flight advantages), maybe pterosaurs shortened the tails and instead grew head ornamets.

[Blade-of-the-Moon]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting. 

[Halichoeres]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

Maybe there's something in Witton's book? I can check next time I'm home.

[Blade-of-the-Moon]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

Maybe there's something in Witton's book? I can check next time I'm home.

I went ahead and ordered a copy myself. I've seen his taking off Tupu but I need the wings spread to try and figure out how best to go about making them later this year.

[Dinoguy2]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

What do you mean by wing configuration? Proportions of the arm and wing finger (visible in the skeletal) or with and attachment of the patagium (which is unknown)?

[irimali]

Yesterday a friend and I had an interesting discussion about the uses of pterosaur tails, and why the drastic change of Rhamphorhynchoidea to Pterodactyloidea took place. I theorized that the long tails of Rhamphorhynchoidea could have evolved to help maintain brief periods of vertically oriented flight. Whether for hovering over shoals of fish or landing on vertical surfaces such as trees the long tail could have given them that extra bit of agility necessary. With some later species retaining these characteristic tails as species identification.

Is it possible that Rhamphorhynchoids retained long tails to help with maneuverability on the ground or in trees?  I'm thinking of animals like squirrels, lemurs and coatis.  With their shorter arms and longer wing fingers, rhamphorhynchoids would have moved differently on the ground than pterodactyloids.  Dimorphodon is thought to have spent more time climbing trees and less time flying than many other pterosaurs so a long stiff tail with a flexible base could have helped it make quick turns and maintain balance on thin branches.   

[Blade-of-the-Moon]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

What do you mean by wing configuration? Proportions of the arm and wing finger (visible in the skeletal) or with and attachment of the patagium (which is unknown)?

Overall wing shape/ silhouette. I bought the book by Witton, there is a nice launching image of Tupuxuara in it but nothing really showing a basic flight position.   I've seen so many interpretations, pointed tips, rounded tips, attachment at the body, knees, feet. Also wingspan length seems to vary, Witton says 13' roughly and others 15-18'. My head is already cut out at 4.5'.

[Dinoguy2]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

What do you mean by wing configuration? Proportions of the arm and wing finger (visible in the skeletal) or with and attachment of the patagium (which is unknown)?

Overall wing shape/ silhouette. I bought the book by Witton, there is a nice launching image of Tupuxuara in it but nothing really showing a basic flight position.   I've seen so many interpretations, pointed tips, rounded tips, attachment at the body, knees, feet. Also wingspan length seems to vary, Witton says 13' roughly and others 15-18'. My head is already cut out at 4.5'.

The problem is that the skeleton of Tupuxuara has never been found other than a few wing bones, so the proportions have to be estimated based on relatives. The shape of the wing and attachment are controversial, though I think the current consensus would be slightly rounded tips with bent wing finger tips, and attachment at or below the knee.

[Blade-of-the-Moon]

I don't mean to derail the discussion, this query is pterosaur related though. I'm trying to get the most up to date concept of Tupuxuara's wing configuration. All the art and diagrams I can find are a bit conflicting.

What do you mean by wing configuration? Proportions of the arm and wing finger (visible in the skeletal) or with and attachment of the patagium (which is unknown)?

Overall wing shape/ silhouette. I bought the book by Witton, there is a nice launching image of Tupuxuara in it but nothing really showing a basic flight position.   I've seen so many interpretations, pointed tips, rounded tips, attachment at the body, knees, feet. Also wingspan length seems to vary, Witton says 13' roughly and others 15-18'. My head is already cut out at 4.5'.

The problem is that the skeleton of Tupuxuara has never been found other than a few wing bones, so the proportions have to be estimated based on relatives. The shape of the wing and attachment are controversial, though I think the current consensus would be slightly rounded tips with bent wing finger tips, and attachment at or below the knee.

So more like this :

Than this ?


The leg placement in the last pic is correct though?  That would effect the wing shape.