Dinner time! Image courtesy of Brett Booth.
Most people who have read even a little on dinosaurs at some point will have seen a photo, cast, model or reconstruction of the famous fighting dinosaurs (and if not, then follow the link to see them). However, while this fascinating fossil certainly tells us that at least one Velociraptor took on a Protoceratops this is pretty much the limit of our knowledge of their interaction from the fossil record. Protoceratops is by far the most common herbivore in the fossil record in which it is found (and of course close relativels like Magnirostris) and Velociraptor (or perhaps rather these days velociraptorines thank to thinks like Tsaagan and Linheraptor turning up) the most common predator. Although the two are quite similar in size, the abundance of both and the abundance of fossils would suggest that the two would have some sort of trophic relationship. i.e. the carnivore would be eating the herbivore in some way at some point.
Naturally one would expect a small predator like Velociraptor to target small prey (like juvenile Protoceratops perhaps) but that hardly rules out their taking the odd swipe at elderly or ill individuals or of scavenging from carcasses. If that was the case, then were is the evidence? Tantalisingly the famous CCDP (Chinese-Canadian Dinosaur Project) team reported often finding velociraptorine teeth with the bones of ornithischian dinosaurs, but without saying which ones they were, so while Protoceratops is the most obvious candidate we can’t say for sure. However, my new paper (you saw this coming, right?) describes a better association – velociraptorine teeth in association with a Protoceratops skeleton and feeding traces to boot.
I’m quite pleased with this work if only because it’s the first paper based on something I found and then wrote up which is rather nice. Credit must go to coauthors Jonah Choiniere and Mike Pittman who originally found the teeth and brought them back to camp. I had the bit of info on the CCDP report in my head and had been thinking about bite marks at the time, so after some pestering they took me to the site and together with Corwin Sullivan we started to sort through all the bone fragments to look for any with bite marks on them. Despite the intensive weathering of the bones, there were some pieces with drag marks from small teeth so we collected what we could and took it back to Beijing.
This paper reports on these finds and as noted above it consists of a couple of dromaeosaur teeth found in association with various bones with some of those bones bearing trace marks. I won’t labour the details, since it’s all in the paper, but I would like to talk about the implications here – are the fighting dinosaurs a one off, or did Velociraptor regularly go after Protoceratops.
As noted above the two animals are similar in length though of course in terms of build and body mass, the Protoceratops would have been the far bigger animal. That suggests that the dromaeosaurs would be unlikely to want to tackle something that big. Those who immediately want to leap and cite the fighting dinosaurs will hit two problems, first and most obviously, this is a single record of a single incident and it’s hard to say if it’s unique or not. Perhaps the Proto was already ill or injured, or the dromaeosaur was desperate, or who knows what. Secondly, big though the Protoceratops is in the fighting dinos pair, it’s actually probably not an adult and is only about 2/3rd adult size, so may have been a more tempting target for a predator (if obviously not a small juvenile).
Protoceratops teeth recovered at the site of our new record are pretty big and there were some fragments of big bones and over a big area suggesting these were the remains of a hefty animal. This would have been quite a challenge for a dromaeosaur to try and bring down. Even if it had, how much could it eat? The bite marks we found were on areas of bone associated with the jaws, hardly the most flesh-rich of areas, and there were multiple repeated bites. Why was this happening?
Velociraptor gets scavenging. Image courtesy of Brett Booth.
The conclusion we offer is that this is the result of scavenging. It’s unlikely a dromaeosaur could bring down such a big Protoceratops. Even if it did, there’d be tons of meat available on the legs and belly and the tail – there’s no need to go and scrape off what little lies on the jaws. Hell, even a whole group would probably get enough food from an animal that big without having to start chewing on the scraps on the face to the degree that they leave so many small marks on the bones. In short, this really looks like a dromaeosaur came across a corpse and scraped off it what it could (a meal is a meal) losing a couple of teeth and making some scrapes on the bones in the process. While this doesn’t support the idea of dromaeosaurs tacking big protoceratopsians for food, it does provide evidence that the former were probably feeding on the latter, even if that largely consisted of scavenging. Still, while such a relationship might be expected, it’s always good to find new information to support ideas and further understanding of the problems.
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Astute readers will have noted that the paper is not actually out yet. However, the journal in question released the proofs version early and the media have picked up on it. I did check with the journal and as far as they are concerned there’s no embargo on it. Since the press have already picked up on it, it would be silly for me not to mention my own research. However, please don’t ask me for a copy of the paper, I don’t have the final version yet and there are things being added to the proofs. My hand is therefore rather forced by others.
Finally a huge thank you to Brett Booth of the Carnosauria blog for producing the images above at short notice and in colour too. The artwork is Brett’s and should not be used without his permission.
Dave Hone's Archosaur Musings 
Congratulations on another paper and one where you also discovered the material. Re. fighting dinosaurs. Perhaps the Protoceratops was defending its young or eggs from the Velociraptor and not a case of the Velociraptor targeting the adult Protoceratops. In other words, anything might have been happening?
Thanks!
As for your point about the FDs, yes there are multiple interpretations possible (and indeed we discuss this in the paper a little). However, I would argue against the eggs thing – for one the nest would likely be preserved and found is the preservation was good enough to save these animals locked in this position (and given the frequency of eggs and nests found at these sites). Secondly, it seems that if you want to steal eggs (especially from something much bigger than you) you wait till mum is not around. If she does turn up, you run, not launch yourself at her. I think this was a genuine predation attempt by an over-cocky predator or a chance encounter that turned violent. Quite what happened, is, I admit, anyone’s guess, but most violent incidents between animals have certain patterns so these at least can inform how we attempt to interpret this stuff.
And, of course, there’s the ceratopsians are omnivores hypothesis (which doesn’t sound all that bad, really) and Protoceratops was hunting Velociraptor! Probably not as likely, but it’s a plausible enough alternative I’d think.
Not that plausible, I think a dromaeosaur would be just too fast to ever get caught. And there’s a difference between omnivory and actively predating large vertebrates. Sure they might have eaten the odd insect or mammal, but hunting dromaeosaurs? I doubt it. Really doubt it.
Those are my exact reasons for doubting it, too. On the other hand, Velociraptor could have been injured, and Protoceratops could have been starving…
I guess it’s fun to speculate, but we won’t ever know.
And, I forgot to add, since it’s just a hypothesis put forth by other dinosaur enthusiasts (albeit those that know their stuff well) I’ve seen on the web, you obviously know better than I.
Well it’s not *impossible*, I just don’t think it’s very likely. One thing worth adding though is that some injuries and illnesses of course do show up on bones. Breaks, infections, and thinks like arthritis can all be seen and none of these are present on either skeleton. This doesn’t mean that both were healthy (malaria can kill you, but it won’t make any changes to your skeleton) but neither at least had any obvious debilitating injuries or illnesses that at least implies bother were healthy when this happened.
I was thinking more along the lines of a muscle injury, though some of those would probably show up on the bones, too.
I don’t find the hypothesis more plausible than its opposite, it was just an interesting idea I’ve encountered I thought I’d mention.
Great illustrations as well! Love Brett’s work.
Hi!
First of all congratulations for such a great blog. It is one of my favorite bookmarks.
Regarding the Velociraptor/Protoceratops interaction. I would imagine that this could also be the result of pack hunting gone bad. One of the hunters was injured deadly by the protoceratops, the other hunters fleeing as a result of the sand storm/land slide or whatever covered the bodies and promoted fossilization.
Of course this view of raptors pack hunting is very popular, especially in Hollywood 😉 , but I´m not sure how much of this interpretation actually is supported by fossil evidence.
Could you comment on this ?
Regards,
Well the evidence for pack hunting in any dromaeosaurs is pretty scant and controversial. Plausible yes, supported by evidence, not really. What evidence there is, is based around Deinonychus in any case and obviously just as there are solitary dogs and cats and group huntng dogs and cats, even if pack hunting was practiced by some, it was unlikely done by all dromaeosaurs.
As to your idea about 1 being injured and the rest leaving, i think it rather unlikely. The Protoceratops in the FD specimen has a dromaeosaur claw in its throat – it was / had likely taken some serious damamge. If this was the case, I’d be surprised if the rest of the hypothetical pack were not able to take advantage. As I say above though, this is a complex and intriguing specimen and despite a number of papers on the subject remains difficult to interpret withut more data. Data we are unlikely to ever recover. Anything is possible, but some are more plausible than others.
While it is *possible* that Velociraptor-adult Protoceratops battles were rare, the chances that an uncommon encounter would just happen to take place right beneath an about-to-collapse sand dune, get preserved, found and prepped are rather staggering. Due to the biases of the fossil record, if something is found, it is unlikely to have been incredibly rare.
I cannot imagine a situation in which Velociraptor, or any carnivore, would prefer to take on large Protoceratops over young/weak ones, however it is worth noting that modern carnivores do often attack relatively large prey. Impala and leopards, tapir and jaguars, white-tailed deer and coyotes, etc. Certainly another specimen like the FD one would be more sure, even if it is unlikely to exist/be found (a rare event could be preserved, but multiple rare events start to change the null).
“Due to the biases of the fossil record, if something is found, it is unlikely to have been incredibly rare.”
That’s true. The corollary of that though is that if you do find 10 000 000 fossils (and we have a lot of fossils) then one of them might well capture a very rare event! I agree in principle, but there is nothing to stop us having found an unusual specimen and this is, regardless of the exact circumstances, already very odd. As you note, to get a second one would be most unlikely.,
Still, other options are available, we might get stomach contents or bones with a mark pattern that do not suggest scavenging, or healed bite marks on a Protoceratop etc. so I would hold out hope for more info.
Any chance you can mention what journal this will be appearing in?
Yes, it’s P3, aka, P-cubed, PPP and it’s actual title – Palaeogeography, Palaeoclimatology, Palaeoecology.