Baby raptors could fly?

Adam Khor

This is not a formally announced study or anything; it's just something I heard from someone, and which has been haunting me ever since. According to him- and a lot of evidence would seem to back it up-, baby dromaeosaurs/raptors would be able to fly, and only become flightless upon reaching adulthood. This would:

1- Help baby raptors fend for themselves in a world populated by other larger predators, including perhaps adult raptors.

2- Allow raptors to fill several ecological niches through their lifetimes, much like it has been suggested for Tyrannosaurus rex

3- Allow baby raptors to spread their species' range better than adults could.

This would mean that some of the juvenile raptor specimens found are probably not different, smaller species, but rather young individuals from other larger species, whether these are known or not. Take Bambiraptor, for example:



Recently suggested to be actually a juvenile Saurornitholestes, and often called the "most bird-like" of raptor dinosaurs. Its forelimbs are quite long and although it lacks a bird-like sternum keel, it has been proven that the keel is not necessary to fly. Pterosaurs have only a very small keel, more like a shallow ridge; so do bats, because their flight muscles are attached differently.
In many sources it is said that scientists "don´t know" if Bambiraptor could fly, which means at least the possibility has been considered.
The same happens with such creatures as Buitreraptor and Unenlagia; the first one is said to have been possibly flighted to some extent, whereas Unenlagia is said to be "too large" to fly, although it does have many flight-related adaptations.

It has also been suggested that Rahonavis, probably the only raptor considered to have been flighted by almost everyone, may actually be the superprecocial young of a larger, yet unknown dromaeosaur.

Nowadays, the most famous superprecocial birds are megapodes, which have very interesting nesting habits to begin with. Most of them bury their eggs; some use mounds of rotting vegetation, like crocodilians, whereas others simply bury the eggs in sand and rely on the sun or even the geothermal heat to incubate them.
(Sauropods were recently said to have done the same; http://blogs.discovermagazine.com/notrocketscience/2010/06/29/giant-dinosaurs-used-the-planet-to-warm-their-eggs/).

Once the little megapodes hatch, they are fully capable of fending for themselves; there is no parental care. Their bodies are covered on soft down but their wings are fully feathered and they can fly within days of being born; some species can actually fly as soon as they hatch, and they are, by the way, much better flyers than the adults. Scientists believe it was the chicks of the megapodes, not the adults, which colonized numerous islands, as many can fly long distances non stop, even though the adults rarely take to the air.

So, the question is, were dromaeosaurs similar? Did the baby raptors hatch fully feathered, with strong bones and muscles and ready to fend for themselves?
If so, this may explain why in the Cretaceous there are few fossils of "bird of prey"-analogues not only among birds but among pterosaurs too. If baby and juvenile raptors were able to fly, they were probably filling that niche. It seems also interesting that rhamphorhynchoids, sometimes said to have filled this niche during the Jurassic, seem to become rarer and eventually dissappear from the fossil record at about the same time raptors appear/diversify.

One last thing; I recently read that the bigger raptors got, the more flexible and less rhamphorhynchoid-like their tails were. This seems to me like additional proof that smaller raptors were doing something similar to rhamphorhynchoids whereas the bigger, flightless ones returned to having a more normal tail.

Oh, and it is possible that some oviraptorosaurs may have been the same.

So, what do you think about this idea, which is, I repeat, NOT mine, but seems to make a lot of sense?

Would a Jurassic Park remake perhaps show a baby raptor leaping into the scientists' face a second after hatching, fully flighted and armed? (I don´t think so, I love the movie as it is, but you get my point)

Kess73

Ahh baby raptor; the T-Rex of the avian world.

Galvasean

Kess73 wrote: »

Ahh baby raptor; the T-Rex of the avian world.

Are you trying to make him angry!?!?!??

It's an interesting theory alright. It would be nice to see it get some mainstream coverage so the idea could really... take flight!

Kess73

Galvasean wrote: »

Are you trying to make him angry!?!?!??

It's an interesting theory alright. It would be nice to see it get some mainstream coverage so the idea could really... take flight!

Nope. Don't want to ruffle any feather by sticking my beak in things.




I don't really buy into the idea of baby raptors being able to fly and then losing the ability as they approached and reached adulthood. There would simply have to be, for me anyway, far too much change in the animal as it aged for it to have happened.

I can buy into the idea of T Rex having different stages as it grew in terms of build/weight etc., but to go from a animal capable of flight (light boned etc) to an animal with much much denser bones stretches it for me. Also the lack of a sternum keel clinches it for me as although the other examples given do not have as large as keel as modern birds, those examples also have a very different skeletal make up to modern birds and that skeletal make up compensates for the lack of a large sternum keel. The raptors mention on the other hand have a skeletal make up that is similar to modern birds and for them to be capable of flight I think that they would need a similar sternum keel for the flight muscles to attach to. Because without that keel I fail to see how the arms of the raptors could be used as wings as there is nowhere else on their skeletal remains that suggests it could accomodate flight muscles and provide the leverage needed for flight.

If modern birds are looked at, then one thing becomes very clear. Nearly all birds that fly have a sternum keel or a similar anchor point to provide leverage, but all of those that are flightless don't have one. I would suggest that the raptor skeletal remains don't have a sternum keel or leverage point for wing muscles simply because they could not fly at any age.

Adam Khor

Not the same thing but, here's a news report about birds seemingly being paedomorphic dinosaurs:

http://www.latimes.com/news/science/sciencenow/la-sci-sn-birds-dinosaurs-20120529,0,7306734.story?track=rss

Galvasean

Also, it appears prehistoric birds flew in a different manner to modern ones. I don't know if this would ad to or detract from the theory in the OP mind you.
http://www.sci-news.com/paleontology/article00359.html

Adam Khor

Galvasean wrote: »

Also, it appears prehistoric birds flew in a different manner to modern ones. I don't know if this would ad to or detract from the theory in the OP mind you.
http://www.sci-news.com/paleontology/article00359.html

Those who defend the idea I posted say that this is actually the key to the whole matter; they didn´t fly like modern birds. Some may have even been able to fly without asymmetrical feathers due to a different arrangement of the wing feathers and other differences.:pac:

I personally like the idea :>

Kess73

Adam Khor wrote: »

Those who defend the idea I posted say that this is actually the key to the whole matter; they didn´t fly like modern birds. Some may have even been able to fly without asymmetrical feathers due to a different arrangement of the wing feathers and other differences.:pac:

I personally like the idea :>

The stumbling block to that, imho, is that to truly fly (and not just be capable of gliding) there still needs to be an anchor point for the wing muscles and the skeletal remains show nowhere where that would be possible. Even modern birds that don't have a sternum keel, still have an anchor point for wing muscles.

Gliding I could almost buy into, but actual flight I am going to remain very sceptical about if the skeleton cannot accomadate wing muscles.

Adam Khor

Kess73 wrote: »

The stumbling block to that, imho, is that to truly fly (and not just be capable of gliding) there still needs to be an anchor point for the wing muscles and the skeletal remains show nowhere where that would be possible. Even modern birds that don't have a sternum keel, still have an anchor point for wing muscles.

Gliding I could almost buy into, but actual flight I am going to remain very sceptical about if the skeleton cannot accomadate wing muscles.

According to those who defend the hypothesis, the flight muscles would be anchored to the vertebrae, not the sternum. Supossedly, the flight muscles of pterosaurs and bats are similarly attached- and the flight muscles attached to the sternum would be an exclusive trait of true birds (including enantiornithines).
I know very little about anatomy though, so don´t take my word for it. I'm just repeating what I've read. :pac:

Kess73

Adam Khor wrote: »

According to those who defend the hypothesis, the flight muscles would be anchored to the vertebrae, not the sternum. Supossedly, the flight muscles of pterosaurs and bats are similarly attached- and the flight muscles attached to the sternum would be an exclusive trait of true birds (including enantiornithines).
I know very little about anatomy though, so don´t take my word for it. I'm just repeating what I've read. :pac:

Bats do indeed have their wing muscles attached as you said, and pterosaurs were similar.

But animals who have their wing muscles attached in such as fashion will have relatively short hind limbs otherwise they would be unable to fly.

If a raptor had it's wing muscles along it's vertebrae, it's long hind limbs would require muscles to allow it to walk properly and then the animal has weight/muscle distribution issues which would make it very hard for it to be able to fly and be able to walk in a bipedal fashion.


A creature that has it's wings anchored with a sternum keel can fly properly, but it can also walk upright easily as well as run/hop with a good degree of agility. An animal that can fly properly but has the wing muscles anchored to the vertebrae will have the on ground capability of a bat and will have no real agility or walking about ability worth talking about.

Given that the raptor has a sketal make up that is not too dissimilar to many modern birds and has long hind limbs that were designed to take the full weight of the animal, I really don't think the largest and heaviest collection of muscles on such an animal could attached to the vertebrae if such an animal could fly.

Adam Khor

Kess73 wrote: »

Bats do indeed have their wing muscles attached as you said, and pterosaurs were similar.

But animals who have their wing muscles attached in such as fashion will have relatively short hind limbs otherwise they would be unable to fly.

If a raptor had it's wing muscles along it's vertebrae, it's long hind limbs would require muscles to allow it to walk properly and then the animal has weight/muscle distribution issues which would make it very hard for it to be able to fly and be able to walk in a bipedal fashion.


A creature that has it's wings anchored with a sternum keel can fly properly, but it can also walk upright easily as well as run/hop with a good degree of agility. An animal that can fly properly but has the wing muscles anchored to the vertebrae will have the on ground capability of a bat and will have no real agility or walking about ability worth talking about.

Given that the raptor has a sketal make up that is not too dissimilar to many modern birds and has long hind limbs that were designed to take the full weight of the animal, I really don't think the largest and heaviest collection of muscles on such an animal could attached to the vertebrae if such an animal could fly.

All very interesting, thanx. However, aren´t some pterosaurs (not all of them, granted, but some, like azhdarchids and other groups) now said to have been quite agile on the ground, some even with erect legs and perhaps even able to gallop to some extent? Some paleontologists have said that azhdarchids in particular could reach about 20 kms p/h which is really not very fast for modern day quadrupedal standars, but still faster than your average Homo sapiens.
Then again, they were quadrupedal, so I guess the weight distribution issues you mention for the raptors wouldn´t apply here.

Assuming that powered flight wasn´t possible, what about gliding at least? Being lightweight animals, do you think they would be able to glide down from a tree branch, for example, to capture prey below? Kind of like modern day potoos or certain owls that don´t really fly much, but just wait perched somewhere for prey to pass by... it would certainly fit the "pinning prey down" idea recently suggested for raptor talons.

Kess73

Adam Khor wrote: »

All very interesting, thanx. However, aren´t some pterosaurs (not all of them, granted, but some, like azhdarchids and other groups) now said to have been quite agile on the ground, some even with erect legs and perhaps even able to gallop to some extent? Some paleontologists have said that azhdarchids in particular could reach about 20 kms p/h which is really not very fast for modern day quadrupedal standars, but still faster than your average Homo sapiens.
Then again, they were quadrupedal, so I guess the weight distribution issues you mention for the raptors wouldn´t apply here.

Assuming that powered flight wasn´t possible, what about gliding at least? Being lightweight animals, do you think they would be able to glide down from a tree branch, for example, to capture prey below? Kind of like modern day potoos or certain owls that don´t really fly much, but just wait perched somewhere for prey to pass by... it would certainly fit the "pinning prey down" idea recently suggested for raptor talons.

Exactly. What I am talking about applies to bipedal animals. The wing muscles on an animal capable of flight generally make up between 12% and 20% of the animal's overall mass. So for the animal to be bipedal the muscles have to be anchored lower down in the body, hence the sternum keel. When these muscles get anchored to the vertebrae, the animal either has to use four legs on the ground or be very clumsy on the ground.

Gliding is a possibility, but they would not be like a Potoo or an owl as those animals are capable of true flight and have anchored flight muscles.

If a very small (and light) young raptor could indeed glide, then I would imagine it was more a mode of transport/escape whilst in trees etc. I don't think they would be glider hunters because of their tail. The shape and length of the tail would see them without a vital part of what makes up a true flighted bipedal predator. Genuine agility in the air would be an issue, and the tail that they had would be a huge factor in that lack of agility.

Another problem, for me, with the idea of them flying is that wings are evolved forelimbs, so for a young raptor to be able to fly but to lose the ability when it got older, it's forelimbs would actually have to devolve to a significant degree, along with some very significant changes to the animal's overall bone structure. The changes to the bone structure I can accept to some degree if the animal went from glider to ground bound as it got older, but the changes needed in the bones to go from being a very light animal capable of true flight to being a heavy ( in compartive terms) ground based predator just seem a bridge too far for me.

Rubecula

This is something I have never heard of before. It makes me think though. It probably isn't actually true, but what a wonderful idea.. Soaring raptors..... oh hang on we have that already according to David Attenborough. LOL

But it is so intriguing.

Adam Khor

Kess73 wrote: »

Gliding is a possibility, but they would not be like a Potoo or an owl as those animals are capable of true flight and have anchored flight muscles.

What I meant was more the hunting method (sit and wait, instead of say, soaring like an eagle or a hawk).

Kess73 wrote: »

If a very small (and light) young raptor could indeed glide, then I would imagine it was more a mode of transport/escape whilst in trees etc. I don't think they would be glider hunters because of their tail. The shape and length of the tail would see them without a vital part of what makes up a true flighted bipedal predator. Genuine agility in the air would be an issue, and the tail that they had would be a huge factor in that lack of agility.

Then perhaps a better comparison would be a cracid, like a guan or a chachalaca?
They live in trees, have long rigid tail feathers, and are generally not much of a flyer but they use their limited ability to leap from branch to branch/escape from the ground to a tree or the other way around etc.

Kess73 wrote: »

The changes to the bone structure I can accept to some degree if the animal went from glider to ground bound as it got older, but the changes needed in the bones to go from being a very light animal capable of true flight to being a heavy ( in compartive terms) ground based predator just seem a bridge too far for me.

Well, never say never... there are plenty of crazy things in nature. I guess we'll have to wait for new discoveries to clear things up.

On a slightly unrelated note, what do you think of the idea that baby pterosaurs were gliders/tree climbers while small, and only became powered flyers later? (I think I posted about it some time ago)

Kess73

Adam Khor wrote: »

What I meant was more the hunting method (sit and wait, instead of say, soaring like an eagle or a hawk).



Then perhaps a better comparison would be a cracid, like a guan or a chachalaca?
They live in trees, have long rigid tail feathers, and are generally not much of a flyer but they use their limited ability to leap from branch to branch/escape from the ground to a tree or the other way around etc.

Well, never say never... there are plenty of crazy things in nature. I guess we'll have to wait for new discoveries to clear things up.

On a slightly unrelated note, what do you think of the idea that baby pterosaurs were gliders/tree climbers while small, and only became powered flyers later? (I think I posted about it some time ago)

I got what you were saying in terms of them gliding to hunt. I just did not think it was a valid option based on the skeletal make up of most raptors. As said in my earlier post, if they could glide I think it was purely as a means of escape/transport rather than a means to ambush hunt let alone active hunting.

As for the chachalaca. Well the Plain chachalaca would be a good example in terms of how I think a gliding capable young raptor would get about in that the plain chachalaca generally will try to outrun a predator or if in a tree will leap and then glide to another branch/tree. But the flipside is that the chachalaca has a sternum keep and has the main mass of it's muscles lower down on its body which allows true flight, accurate gliding, and powerful running. A raptor with it's bipedal frame and no sternum keel has a sketal structure which is set up to take the largest group of body muscles lower down in it's body to power it's mode of locomotion which based on it's skeletal frame would be a combination of leaping, running, and a fair degree of terrestrial agility.


As for pterosaurs being gliders/tree climbers when young. I think for many types that is very plausible, in fact I think that it was almost a certainty for some types to be honest. I think that the majority of pterosaurs were quadrupeds, and the anchoring of their wing muscles supports this more than any of the tracks that have been found. Most quadrupeds with the capablity to glide have the ability to cling to surfaces and climb surfaces so it is very reasonable to think that up to a certain size/weight that animals with a very similar physical set up would have done likewise in the past as well.

I think that many of the smaller pterosaurs were tree climbers/clingers as adults and if not trees then rock surfaces etc.

Adam Khor

Sorry bout bumping this thread, but I was re-reading it and it occured to me... what are your thoughts on Sharovipteryx, said to be a glider but with its patagium anchored to the hindlegs?

Rubecula

Well flying and gliding have both evolved a number of times throughout time, so I am sure there have been a few differing methods that have appeared. I see nothing wrong in using hind legs as "wings". Some have had four wings after all, and the same thing applies to fins for swimmers. Flying and swimming are pretty much the same thing when you think about it, just one is in a thicker medium.

I have no problem at all with hind legs for motive power in the air, although I have no idea how efficient it may have been. If it was as good as or better than using forelimbs then it would possibly still be around, as it isn't I imagine there were some drawbacks to it. But who knows?

Kess73

Adam Khor wrote: »

Sorry bout bumping this thread, but I was re-reading it and it occured to me... what are your thoughts on Sharovipteryx, said to be a glider but with its patagium anchored to the hindlegs?

I would see it as a glider that was designed to be very efficient at going in straight lines, but poor in terms of maneuverability.

Adam Khor

What bothers me is that its forelimbs are so small... wouldn´t that affect its balance while gliding?

I don´t think there's anything quite like it in modern times; all gliding animals have much more uniform gliding surfaces:

Mind you, I'm not saying that I think Sharovipteryx couldn´t glide, or anything like that- I'm only curious as of how it "worked", so to speak. For some reason I find it difficult to picture in my head. Not only how it glided but also how it landed...

Kess73

The small forelimbs just add strength to the theory that it was a straight line glider. They would give stability in a straight line and help to maximize speed in that straight line.


My own thoughts would be that it did not hunt in the air, and only used it's gliding ability to get from point to point or to escape a predator.

Mullerornis

Hi everyone.

In regards to flight in non-avian dinosaurs, while the hindlimbs are a valid argument, it's worth to note that Microraptor preserves well formed deltatoideus complexes. This means that a bat-like stroke was present.

We defenitely need more studies, but the potential for unorthodox flight styles was there.

Capt'n Midnight

Mullerornis wrote: »

We defenitely need more studies, but the potential for unorthodox flight styles was there.

In the kingdom of the blind the one eyed is king.

If there is no competition then you don't need to be a particularly good flier to benefit. Even today flying fish and other gliders show this. If you live in a forest being able to get to another tree most of the time is nothing to be sniffed at.

Adam Khor

Mullerornis wrote: »

We defenitely need more studies, but the potential for unorthodox flight styles was there.

Hey, you never know Maybe Epidexipteryx's tail feathers were helicopter rotors...

Galvasean

Hmmm, sounds to me like Adam is clutching at Longisquama shaped straws...

Adam Khor

Galvasean wrote: »

Hmmm, sounds to me like Adam is clutching at Longisquama shaped straws...

Whatever, don´t deny that the thought is awesome XD

Mullerornis

Adam Khor wrote: »

Hey, you never know Maybe Epidexipteryx's tail feathers were helicopter rotors...

We do currently know scanciopterygids had wing feathers, so they're in the list of gliding/flying dinosaurs.

In addition, it has been suggested enantiornithes might actually be sister taxa to them rather than Ornithurae.

Galvasean

Adam Khor wrote: »

Whatever, don´t deny that the thought is awesome XD

On that note, are there any or have there ever been any creatures in nature that developed a helicoptor like style of flight?

Adam Khor

Galvasean wrote: »

On that note, are there any or have there ever been any creatures in nature that developed a helicoptor like style of flight?

Not that I know of but, wouldn´t it be awesome?

I'm sure it must have evolved in other planets at one point. Maybe it even will in our own planet, millions of years from now...

Capt'n Midnight

Adam Khor wrote: »

Not that I know of but, wouldn´t it be awesome?

I'm sure it must have evolved in other planets at one point. Maybe it even will in our own planet, millions of years from now...

Unlikely here because of the way balance organs work and our predisposition to bilateral symmetry


though microbes do have rotary mechanisms


and it wouldn't be a huge surprise to find out that some parasite make sycamore seeds bigger or better somehow