Velociraptor scavenging an azhdarchid pterosaur

Image courtesy of, and copyright to Brett Booth.

So yesterday at short notice I rushed up this teaser post which seemed to do the trick, and now I’ve got a bit more time on my hands, I can start putting down a proper post on the subject. Yep, I have a new paper out and this time featuring dromaeosaurs and pterosaurs. Long time readers will remember that almost exactly 2 years ago I had another paper out on dromaeosaur scavenging featuring shed teeth and bite marks on some Protoceratops material. Coupled with the famous fighting dinosaurs specimen we have pretty good evidence for dromaeosaurs, and specifically Velociraptor for feeding on this dinosaur. The record of dromaeosaur predation and feeding is actually pretty good compared to other theropods groups and there is also an isolated pterosaur wing bone from Canada with shed dromaeosaur teeth and bite marks.

This ‘new’ specimen marks the first record of gut contents for Velociraptor and the first record of a pterosaur bone as gut content in a theropod. (The ‘new’ is becuase this specimen was actually found in the 1990s, but has yet to be described, though I’m told there’s a photo of it in Luis Chiappe’s recent birds book). Thus we do have rather exceptional evidence for a Velociraptor chowing down on an azhdarchid.

Velociraptor specimen with a pterosaur bone as gut content (black arrows). From Hone et al., 2012

And here it is, well part of it. The Velociraptor in question was remarkably well preserved and complete which allowed the preparation of it with the chest cavity as a single articulated piece with the vertebrae, sternum, ribs, gastralia and even uncinate processes all intact and in their original positions. The bones are really well preserved and much of the material has been prepared free of the matrix entirely. One obviously example is the skull which, bizarrely, is on display in Barcelona so at least some reader might have already seen that, though sadly I haven’t and had to rely on some superb photos kindly sent by Fabio Dalla Vecchia. It’s hard to show the bone off properly what with the whole ribcage in the way (which is, incidentally, a broken ribcage, one of the ribs took a huge battering and shows a healed break – white arrow in the above picture). S you’ll be delighted to know there are also some close-ups in the paper like this one (below) and even some CT scans in the supplementary data.

Close up of the bone. From Hone et al., 2012

As you can see the bone is incredibly thin-walled which is the major reason that it’s inferred to be an azhdarcid pterosaur, though their presence in the Late Cretaceous, including a related formation, and the general absence of other pterosaurs in the Late Cretaceous helps support this identity. Given what is around and the thinness of the bones, it’s pretty unambiguous as indeed is the identification of the dromaeosaur as Velociraptor given that we have basically the whole thing. In short, this is about as convincing a case as one could make that a Velociraptor had eaten an azhdarhid. But was it really scavenging? Well that and other issues I’ll be talking about tomorrow, as there’s quite a lot more to say on this. Stay tuned.

Finally, my thanks to Brett Booth for more awesome artwork for me to use, and you can see more of this and my interview with him on his dinosaurs here.

Hone, D.W.E., Tsuhiji, T., Watabe, M. & Tsogbataar, K. Pterosaurs as a food source for small dromaeosaurs. Palaeogeography, Palaeoclimatology, Palaeoecology, in press. Horrible uncorrect proof and behind a paywall, but the abstract, figures and other bits are visible to all.

15 Responses to “Velociraptor scavenging an azhdarchid pterosaur”


  1. 2 Henrique Niza 04/03/2012 at 2:33 pm

    That is indeed awesomely cool!

  2. 3 Zhen 04/03/2012 at 2:56 pm

    What are the chances of this pterosaur being caught and eaten as opposed to being scavenged?

  3. 6 Briane Pagel 04/03/2012 at 6:01 pm

    I’m no scientist, but I’ve commented on this before. This find and the “fighting dinosaurs” fossil of your other post back in 2009 need to be better explained.

    Is there ANYWHERE I can find a scientific explanation of how a fighting dinosaur would be locked in mortal combat with an enemy, only to DIE IN THAT POSE, and then be FOSSILIZED in that pose… in an era where there were scavengers and given how long it takes for bodies to decompose and then be fossilized?

    This post doesn’t quite strain credulity the way “fighting dinosaurs” does, as it’s more possible, I suppose, that a ‘velociraptor’ ate some carrion and died before it had fully digested it. But I don’t doubt that within six months, paleontologists will have vivid descriptions of velociraptors leaping off cliffs onto the backs of pterosaurs, eating them as they fall and ripping them to shreds.

    I’m trying to have an open mind, but still:

    http://www.troublewithroy.com/2010/03/best-way-to-prove-scientists-are-making.html

    http://www.thinkingthelions.com/2008/07/me-2-science-0.html

    • 7 David Hone 04/03/2012 at 6:19 pm

      “Is there ANYWHERE I can find a scientific explanation of how a fighting dinosaur would be locked in mortal combat with an enemy, only to DIE IN THAT POSE, and then be FOSSILIZED in that pose… in an era where there were scavengers and given how long it takes for bodies to decompose and then be fossilized?”

      Well the fighting dinosaurs specimen has never been well described properly and there’s not much we can do about that. However, there is a very well known feature of that specimen which certainly is a reasonable explanation of how they could end up like that. The arm of the Velociratpr is locked in the mouth of the Protoceratops, whereas the claws of the former are stuck in the throat of the latter. It is unlikely an incident, but not impossible, that they killed each other – it odes happen. Moreover, both this specimen, and the one I describe here, and many others from these beds are preserved in wind borne deposits. Basically, they are buried in sandstorms. That certainly can bury things almost instantly and render them immobile such that they will die in the posture they were in at the time, and probably won’t be found or reached by scavengers. Don’t forget that in desert conditions, things tend to dry out rather than rot (few bacteria etc) and mummify so they won’t stink and attract scavengers and may be buried under feet of sand in depth. Again this happens today and things like camels can be buried in sandstorms, get trapped and die and mummify.

      “This post doesn’t quite strain credulity the way “fighting dinosaurs” does, as it’s more possible, I suppose, that a ‘velociraptor’ ate some carrion and died before it had fully digested it.”

      Might I infer from this that you haven’t actually read the paper where I discuss the inferences for scavenging? If you come back tomorrow I have a whole post on it.

      “But I don’t doubt that within six months, paleontologists will have vivid descriptions of velociraptors leaping off cliffs onto the backs of pterosaurs, eating them as they fall and ripping them to shreds. ”

      A) No they won’t, don’t be mean / silly. B) There are multiple incidences of pterosaurs being eaten by dinosaurs (and even fish) and while these may not be predation specifically it’s not an unreasonable inference. Birds are regularly caught and eaten by terrestrial predators today, pterosaurs would not have been immune. C) your arguments are contradictory. You don’t seem to deny that the bones is right inside the Velociraptor so presumably you’re happy that it was actually eaten. However, you seem to be sceptical that it could have been scavenged and yet sarcastically comments about them jumping onto a killing pterosaurs. Well it either killed it and ate it, or scavenged it, yet you seem to regard both as unlikely.

      You seem to be implying from the links you put up (which I’ve not read in depth, they are rather long) that I / and or other people are making things up. I’m not. I appreciate that yes, there is a chain of logic here rather than anything definitive. But that is the point, there is a chain of logic and lots of actual individual data points and bits of evidence here. The geology tells us its a wind deposit. Modern studies tell us that animals do get trapped and die in these. The size of the Velociraptor is known. The size of the bone is known. We can scale both of these to get a good idea of relative sizes. We can see there’s no acid etching on the bone so it can’t have been eaten long before. We have other specimens that show the patterns of feeding of theropods, including dromaeosaurs. We have studies of living animals and how they hunt, scavenge and feed. We have comparative studies about the types of marks made and what they mean for feeding.

      You see the bone in the gut and me say it’s scavenging and conclude it’s a just-so story. You don’t see, or read about or know about all of this stuff so you assume it’s speculation. It’s not. It’s reasoned inference based on the available information, analysis, and logic. Sure, it could be wrong, we’re working on probabilities, not absolutes. But all science works on those, it’s just a question of degree, and here I think it’s really rather strong.

      • 8 Paul W. 05/03/2012 at 1:46 am

        The ‘archaeologists’ made ‘velociraptor’ up, apparently. It seems a lot of time to waste on a piss-take.

  4. 9 Holly 04/03/2012 at 11:01 pm

    This picture makes me wonder… I volunteer at a bird rehab center and it is not uncommon for a hawk to come in that has eaten splinters bone, usually from road kill, and had the splinters pierce their crop. I wonder if dinosaurs had this problem? Do we know if they had crops?

    • 10 David Hone 05/03/2012 at 8:11 am

      Good question! The short version is that I’m not sure as I don’t know my basal birds too well from which to make the most obvious inferences towards dinosaurs. That said, it’s certainly not unreasonable that some did and I’d call it plausible at least. I’ll have to look into it more, thanks for the inspiration to check.


  1. 1 Yum! Velociraptor Eating a Pterosaur « A Bitter CynoAnarchist Rages On Trackback on 04/03/2012 at 9:03 pm
  2. 2 More on dromaeosaurs vs azhdarchids « Dave Hone's Archosaur Musings Trackback on 05/03/2012 at 8:40 am
  3. 3 A Dinosaur's Pterosaur Lunch | Dinosaur Tracking Trackback on 05/03/2012 at 7:35 pm
  4. 4 Zoe – It's Our Nature : Velociraptor’s Last Dinner Trackback on 08/03/2012 at 1:48 pm
  5. 5 Velociraptor’s Last Dinner | ZoeNature Blog Trackback on 08/03/2012 at 5:31 pm

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