Tet Zoo picture of the day # 11

"he has - for sure - used artistic license..."

Consider yourself lucky I didn't include the logical progression from a bristly face: a dense network of super-long whiskers around the nose, thereby explaining the enormous nasal cavities. They used them to detect the Speilberg-esque booming footsteps of approaching tyrannosaurs and stuff.

Seriously though, if anyone should be willing to share their thoughts on ceratopsian omnivory, I'm very interested in knowing what people make of this idea. In the mean time, here's a tip of the hat to Darren - I'm flattered, obviously.

Reminds me of the old Jim Henson show Dinosaurs, where the main character's boss was a Styracosaurus who loved to eat mammals.

Anyways, and feel free to rip this apart, I have a hard time imagining the larger ceratopsians being active scavangers, but the smaller, more basal ones, your Psittacosaurs and your Protoceratopsi (Protoceratopses?) those I could see scarfing down the ocassional carcass. Though, I have no problem with the larger ones chowing down on the ocassional small critter that they happened to come across while grazing.

Very interesting, or perhaps better said: WTF?!
Well, the idea of omnivory in normally herbivorous animals is interesting. Just some days ago I wrote at my blog about occasional carnivorous behavior of modern hoofed mammals. There are also not only small hoofed mammals (from which some practice also actual hunting) which eat also meat, but also biggers. Not only the well known omnivory of pigs, but there is also occasional scavenging in hippos and dromedars, and deers eat sometimes eggs and small birds, whereas rendeers even consume large amounts of lemmings. Large extinct mammals like entelodonts and several of the mega-carnivores were also probably omnivorous, so I would not be surprised if some normally herbivorous dinosaurs also had a taste for meat.
BTW, great Paleo-Art Mark!

I have always been fascinated by occasions of carnivory among hippos: they have been filmed eating carcasses, and killing and eating swimming impalas (these occasions perhaps initiated by starvation and/or territoriality). A captive hippo once kept at a British zoo ate a flamingo, a tapir and some other animals. Deer are well documented for feeding on bones, and even biting the heads and feet off seabird chicks, rabbits and other animals - in part this is because they apparently develop a craving for calcium for their antlers. And of course, deer eat antlers whenever they find them. Giraffes and other artiodactyls will also chew and eat bones. It is well documented that elephants will exhume and eat carcasses on occasion, and a starving captive elephant once ate a person. Tapirs, muntjac, duikers and other small hoofed mammals are partly omnivorous and will eat birds, frogs and small mammals. Dugongs are partly omnivorous. All living herbivorous reptiles (tortoises, iguanas etc) eat animal material on occasion, and apparently need to to stave off various deficiences.

I find it hard to think that 'herbivorous' dinosaurs like ceratopsians didn't take advantage of bones and carcasses at least on occasion... though, obviously, no-one is going as far as saying that they were vicious flesh-rending carnivores. That would be very silly...

I can't comment on flickr, so... coronoid process :-)

Some years ago I also saw in a documentation a hippos which ate from a large dead animal, but I can´t remember what it was. Given the fact that hippos are sometimes very aggressive towards other animals, I could well imagine that they sometimes consume also animals which they killed cause of aggressivity, and not primarily to eat them, similar as crocodiles do it sometimes.
Duikers are among the most fascinating omnivorous hoofed mammals, as it seems that it is a very common behavior to hunt smaller vertebrates. There is a very well documented case of a duiker at the Zoo of Zürich, which was observed eating dead birds and hunting living pigeons at every opportunity, with hunting manners similar to true carnivores. The way it ate larger birds was also strange, it killed them with a bite in the belly or chest, chewed off the head, the legs and wings, but ate only the head. Then it sucked of the innards and at the last pieces of the carcass.
The underwater fish-hunting of chevrotains is also really remarkable, even if they eat in general smaller animals than duikers.
That also tapirs, giraffes and dugongs eat als animals was really new to me, thanks for the info.
About three months ago I saw also a (new)documentation about some kind of religious elephant centre, somewhere on an Asian island. I can´t remember anymore where it was. There was one big elephant bull which had already killed several people. Okay, that´s not really uncommon, but strange it was, that it also ate this people. One of the monks (or whatever they were) said this is really uncommon, normally elephants don´t eat humans, but this one did it for several times, and I don´t think this was just an invention. I suppose this is one of the least-known phenomens about elephants, and I suppose most people would completely deny it.
There was also a young cow at India some months ago, which started to eat chickens.

"I can't comment on flickr, so... coronoid process :-)"

Why, that's what it says (cough).

Omnivory in ceratopsians? My intial reaction is "no," but knowing that many modern mammalian herbivores chew on carcasses from time to time, I'm more inclined to say "maybe." Mammals, however, have the advantage of heterodonty. Molars are crushing teeth, but ceratopsians had slicing teeth, which I doubt could crush any bones or rend much flesh. Granted, those beaks were powerful, but also not never maneuverable. Another plus for mammals is that they tend to have lips and incizors for selectively picking off the meat they want. Ceratopsians have a turtle-like, immobile beak which in all likelihood wasn't very subtle in its selection.
I can sort of buy the bristle structures, but I'm warry of omnivory in the larger ceratopsians.

"...and a starving captive elephant once ate a person."

!?!?

I demand to know more of carnivorous habits of hippos and elephants!
Hippos I can understand...but elephants? With their flat grass grinding teeth?

Darren, a full post on predation, scavenging, and osteophagy in normally herbivorous animals is required. Give us our meat!

And Mark: damn. You rock. Anytime you want to put some of these images on t-shirts or posters (at CafePress or Zazzle), or (fingers crossed) publish a book, you'll have at least one loyal customer. But probably thousands. Keep up the good--no, great--work.

Darren, a full post on predation, scavenging, and osteophagy in normally herbivorous animals is required. Give us our meat!

Ok, as you command. One reason I've avoided this is that I've said it all before. However, I'm sure I can drum up some new stuff.

Zach: I don't get your logic. I was going to say 'turtles' at you and leave it at that, but you mention turtles anyway.

Ah, I myself have drawn a study that follows this line of thought, but it is of a Triceratops horridus and lacks the facial hair.

But are the turtles scavenging the remains of carcasses or are they just snapping at passing lizards and mammals? My ultimate point is that ceratopsians' jaws and dentition seem specialized toward slicing vegetation, whereas mammals have lips incizors for picking and molars for crushing. I'd be more inclined to think of ornithopods as omnivores, given their tendancy toward being able to chew things.

Maybe I'm not making sense. :-(

-Sordes.

Duikers crush the chests of large birds for the same reason small carnivorans do, it irreversably collapses their lungs, ensuring immediate suffocation.

Passerine collecters know this very well.Its considered a humane way to quickly kill a small bird by pinching its chest.

[from Darren: it's used on bats too]

You can use large, flat-surfaced teeth to pulp and grind up meat. BTW, a ceratopsian could use his beak to take chunks out of a carcass. They were evolved for handling tough woody plants after all.

Dr Vector - you're my new best friend.

Zach, I'm afraid I disagree with some of your points. The ceratopsian beak is far narrower than that of many dinosaurs including ornithopods, which are rounded in iguanodontians and highly spatulate in hadrosaurs. As such, I imagine ceratopsians were much more selective in feeding than other ornithischians.

Furthermore, the shearing cheek teeth of ceratopsians are probably better suited to processing meat than the grinding teeth of ornithopods: it is far easier to cut meat than pulp it, after all. The shearing mastication of ceratopsians would cope with meat just fine: felids, which prefer fleshy muscle tissue to other options on the carnivory menu, do not grind or crush meat, prefering just to slice it up. Granted, this method of food processing does not lend itself well to bone crunching, but neither does the pleurokinetic grinding system of ornithopods. However, a grinding masticatory system is far better at processing vegetation as it physically breaks down that oh-so-stubborn cellulose which causes so much grief in herbivore guts. As such, ornithopods were almost certainly better adapted for herbivory than ceratopsians.

Additionally, although ceratopsians do not have heterodont detention, they still possess differentiated mouth parts. The ceratopsian beak was almost certainly an integral part of food gathering and performed a different function to the chewing dentition behind it. Furthermore, the absence of incisors and lips does not prohibit carnivory: predatory birds seem to do just fine without both. Furthermore, birds that are adapted for pulling carcasses apart have robust, deep and highly recurved bills - just like those of ceratopsians.

Of course, I'm not arguing that ceratopsians were exclusively carnivorous or anything - far from it. I'm merely suggesting that a wholly herbivorous diet is inconsistent with the structures we see in ceratopsian jaws. A richer omnivorous diet consisting of fibrous or turgid plant matter (there's a picture of a Chasmosaurus uprooting a tree to get at the tubers beneath it just waiting to be drawn) and a healthy dose of carrion is perhaps more in keeping with their mouthparts. At least, that's how it appears to me.

I am not very familiar with ceratopsian beak-anatomy, but I suppose a comparison with turtles wouldn´t be completely false. Some turtles like alligator turtles commonly eat from big carcasses, but their beak is also more similar to those of a bird of prey. But also the nearly completely herbivorous terrestrial tortoises like those of Galpagos eat meat on occasion, mainly carcasses (and even poo, but that´s another thing). A beak like those of the ceratopsians would be much more effective to tear of pieces of meat than the incissor-less upper jaws of most hoofed animals. The duikers for example have to use their molars to bite, and even this works, although their teeth show no adaption for carnivory.
But anyway, I can´t imagine that scavenging was really a common phenomen in ceratopsians. Given the fact that this were huge animals, and probably lived in herds, there was surely not enough carrion to play an important role in their diet.
In fact I have really problems with the thing that many paleontologists seems to think that animals of any size can life alone from carrion. In this case it is different, because it is only an assumption that some herbivores ate on occasion also meat (what seems really not unprobable) but everytime I have to read that absolute ܢUeber-Carnivores like Spinosaurus or T-rex were only scavengers, I get sick. Especially if you look at the reasons for alleged scavenging behavior. If an animal with very strong jaws is discovered, some people claim it was a scavenging bone eater. If a carnivore with weak jaws and thin teeth (like Dilophosaurus or Carnotaurus) is found, others claim it was too weak to kill prey, and must therefore have lifed from carion, especially rotten meat...I have even read that sabertoothed cats were only scavengers, which used their teeth to slice the hide of big dead animals. Why didn´t the jerks who claims this that carnivores like tigers and lions not only can open even elephant carcasses without saberteeth, but also that especially carcasses of such large herbivores are far away from being common in normal ecosystems.
BTW, thanks for the info Raymond.

I understand that ceratopsian beaks were narrow and pointy--don't get me wrong. And yes, I suppose their slicing teeth would be well suited for cutting flesh. Hell, I suppose it's possible. :-)

Mark: That drawing of Chasmosaurus uprooting a tree? I got this!

Hi Darren,

Sorry, couldn't resist a plug for my own papers. As you might remember I've published on the possibility of dinosaur omnivory in a couple of papers: one dealing largely with prosauropods (but speculating on some other dino groups too) and one based largely on theropods. My take on the whole issue is that 'unspecialised' herbivores (i.e. those without sophisticated grinding dentitions, for example) are the most likely candidates (and there are various other things that can be factored in here: body size, enviromental and ecological factors, gut contents, other features of the anatomy [e.g. claw morphology, hand function]). Omnivory is, of course, the hardest diet to prove in an extinct animal as there are no sure-fire anatomical signals that support habitual omnivory to the exclusion of low level herbivory or carnivory. Discussions of dino omnivory can be found in Barrett (2000) [Evolution of Terrestrial Herbivory volume, CUP, mainly prosauropods] and to a lesser extent in Barrett (2005) [Palaeontology: theropods]. I'm afraid I don't find the idea of omnivorous ceratopsians particularly convincing, not even for basal taxa within the clade: everything about ceratopsian skeletons yells herbivory - no features of the anatomy look 'dual purpose'. They might have indulged in occassional osteophagy as almost all obligate herbivores do occasionally to get their Ca and P, but I'd suspect that this would be a rare occurence. Still, we have yet to find any gut contents for any ceratopsian...

Cheers, Paul

Many thanks to all for their comments, especially the good Dr Barrett (as I said to Mark Witton earlier today, I was hoping that this topic of discussion might prompt you into leaving a comment!).

My opinion on this is unchanged (see above), and is pretty much the same as Paul's anyway, but.. one comment: yes, everything about ceratopsian skeletons yells herbivory, but is this necessarily reliable when we have such things as peccaries, pigs and (shudder) entelodonts?

Hi Darren, You're quite right - as far as establishing omnivory is concerned, there is no substitute for behavioural data from a living animal. Cheers, Paul

there's a picture of a Chasmosaurus uprooting a tree to get at the tubers beneath it just waiting to be drawn

The Stout/Service The Dinosaurs has a picture of a Styracosaurus munching on an uprooted cycad, but I can't remember if it was chomping on the leaves or the roots. In any case, I agree, this field is under-explored.

Hmm, I wonder if any artists of the extant have depicted the majesty and wonder of a deer eating the feet off a baby seabird.

I am fascinated by the way that behavior is often broader (for want of a better word) than morphology alone would predict. Predatory deer, mud turtles in trees, and ornithopods in burrows are all good reminders that the range of 'normal' behavior for most taxa has long, strange tails.

An interesting topic! I have a hard time feeling skeptical about it, since I've had (idle) thoughts about boar-like protoceratopsids, myself.
Although, since certain fossils are now known to be brooding Oviraptors rather than raiding Oviraptors (one seemingly attacked by a Protoceratops, IIRC?), can we be certain about who's the hunter and who's the hunted regarding the famous Velociraptor/Protoceratops fight-scene fossil? :D

Finally: "(shudder) entelodonts"? What's wrong with them? They're great...

Finally: "(shudder) entelodonts"? What's wrong with them? They're great...

Being frightening is part of their greatness...
There is nothing wrong with them, I just don't want to meet one in the wild (at least not without a couple of RPGs for self-defence).

when we have such things as peccaries, pigs and (shudder) entelodonts?

Entelodonts have dentitions much like Eocene whales, except some have serrated canines. Shudder indeed.

Have there been dentition studies on ceratopsians to see what kind of wear patterns they had on their teeth? Surely this would help to settle the matter.

> Duikers crush the chests of large birds for the same reason small > carnivorans do, it irreversably collapses their lungs, ensuring
> immediate suffocation.

Raymond,
Dasyurids do this, too. They seem to be actually more effective predators of large and aggressive birds than small carnivorans are: Wekas frequently beat up weasels, stoats and polecats, but I have never heard of a weka (or even a pair of them) defeating a quoll.

-Johannes

Thanks for the info, I vaguely remember an old article stating that introduced spotted quolls were increasing in numbers in New Zealand at the expense of mustelids and felids.IIRC, the article actually stated they were killing every cat and mustelid on sight.Bizarre, since aussieland quolls are retreating before the feral carnivorans.

Some time ago I saw a life-sized reconstruction of an Entelodon. It was really nice, inclduding an open mouth with all teeth. When I looked at those teeth, I asked me if Entelodonts were actually able to crush bones. The molars are compared to the huge jaws really tiny, and they have also huge interdental gaps. I see no way how they should have managed to crush any bigger bones or just shear flesh. They look more like the molars of moden pigs or even humans (which have both not those missing approximal contacts), but I really see no resemblance to the bone-crushing teeth of hyenas, wolves or even marsupials. I have also distinct problem to imagine this animals to eat meat at all, although it looks well if such a beasts dine on a carcass. Okay, modern pigs can also devour flesh, but there dentition is also not very well-suited to do this. Entelodons are widely accepted as giant scavengers, but their teeth look really not well-suited for this.

I must say that the ill tempered Styracosaurus eating the occasional game or carcass that came by is very intriguing; after all hippopotamuses have been known under small occasions to eat smaller swamp relatives if it has the chance to, when under stress; Ceratopsians may have behaved as very brutish and ill tempered animals especially when their newly hatched calves were beginning to walk. Interestingly creatopsians replaced the older sauropods groups that were dying out as the great forests of the Jurassic faded away, so they feed on large quantities of plant matter therefore ceratopsians must not have needed extra protein meat as all their nutrients derived from vegetable matter from the newly arising angiosperm forests; their size needed less nutrients in proportian than the average and smaller herbivores such as hypsilophodonts that needed a insect protein rich diet to consolidate their every day diet with an extra protein and minerals.
However it isn't excluded that smaller ceratopsians such as protoceratops from behaving like pigs, digging up the already poor in nutrients soils of the mongolian deserts eating the occasional velociraptor chick.

Interestingly creatopsians replaced the older sauropods groups that were dying out as the great forests of the Jurassic faded away

No, no, no, no. Nothing happened to the forests. Titanosaurs -- Late Cretaceous sauropods, in other words -- were highland animals, and ceratopsids were lowland animals.

the already poor in nutrients soils of the mongolian deserts

Is that something we know?

Protocreratops did live in a desert like environment; in 1971, a fossil of velociraptor fighting with a protocreatops was found; one of the theories surrounding their mysterious death was that they were suprised by a sandstorm moreover the fossil was buried in sand indicating that the area was a semi-arid environment.
I am sorry to differ with you but i am sure that most sauropods died out in the Jurassic because great conifer forest were replaced by flowering plants; i didn't say all of them.
If not, then what are your explanations for the Jurassic-cretaceous extinction?

Protocreratops did live in a desert like environment

Sort of, yes -- but I was asking about the nutrient content of the soil, not its water content.

(Besides, they didn't die in sandstorms, but in rainstorms that made the sand dunes collapse. You're about 15 years behind the times.)

i am sure that most sauropods died out in the Jurassic because great conifer forest were replaced by flowering plants

But there were no flowering plants at the J-K boundary! Flowering plants only became common during the latter half of the Early Cretaceous, and that gradually! The oldest angiosperm wood dates to shortly before the Early-Late Cretaceous boundary.

The J-K boundary* mass extinction appears to correlate with an impact... but even things like the size of the extinction are still very poorly known.

* Or two million years later. Apparently the boundary is badly defined. That appears to be why the site of Purbeck in England crosses the boundary.

There are a lot of facts that you need to look up. Google is your friend!

Quite on the contrary primitive flowering plants did occur during the Jurassic...`
According to this site* a book called Dynamics of Dinosaurs and Other Extinct Giants, 1989 by R.M. Alexander flowering plants started to take their hold on the plant world in the Jurassic; Bob Bakker also state this according to this site **; an other site*** states that they appeared 140 million years ago; Dong Ren in the April 3 issue of Science shows that flowering plants did evolve in the mid Jurrassic as flies in amber were found to have nectar in their abdomens. and to top it all a book also states this ( Wildlife Issues in a Changing World By Michael Platt Moulton, James Sanderson)

You're right Google is my best friend :)

Of corse it seems that you know i bit more on the protceratops subject than i do and i must admit i am 12 years late on the subject after all.... i read in 1994 a issue of national geographic that states that the mongolian desert although a little more humid was still an arid or semi-arid region ( you know the issue with this picture on ?http://www.animalpicturesarchive.com/ArchOLD-4/1126428974.jpg)

* http://waynesword.palomar.edu/ww0803.htm
**http://palaeo.gly.bris.ac.uk/communication/Mcgowan/PLANTS
***http://www.economicexpert.com/a/Flowering:plant.htm

According to this site* a book called Dynamics of Dinosaurs and Other Extinct Giants, 1989 by R.M. Alexander flowering plants started to take their hold on the plant world in the Jurassic

Well, wrong. Also, the book is generally outdated, and furthermore, it's not a botany book in the first place.

Bakker's 1986 book is even more outdated, but IIRC it doesn't make a specific claim that the floral turnover happened right at the J-K boundary anyway.

an other site*** states that they appeared 140 million years ago;

That was when some people believed that the Yixian Fm, which dates to the middle of the Early Cretaceous, was end-Jurassic in age. It's wrong, as a couple of papers on detailed radiometric dating show (starting in 1999). And of course economicexpert.com has slept through the progress of the last 10 years.

Dong Ren in the April 3 issue of Science shows that flowering plants did evolve in the mid Jurrassic as flies in amber were found to have nectar in their abdomens.

April 3 which year? And where in the world does Middle Jurassic amber occur?

i read in 1994

And in 1998 this came out. Unfortunately it doesn't cite any sources, but I've seen many scientific works and secondary literature like Glut's "Dinosaurs -- The Encyclopedia" make the same claim, so citations should be able to be found.

This dosnt make any sense. ceratopsians were not designed to eat meat. Exhibit A: thier teeth are small but great for grinding up plants but not for chewing meat. Exhibit B: thier beak is like scissors good for cutting off plants not meat. I could see mabye a dinosaur like chaoyangsaurus doing this but not a sryrac. But my personal opinion is that chaoyangosaurus of pssitacosaurus are not even related to triceratops of styracosaurus.

@seth: You seriously missed the conversation above. Please pay more attention before posting.

As a whole I think ceratopsian omnivory is undeniable, even if it was just partial as in hippos. There is no doubt they would had been primarily herbiorous, but certainly their jaws say they were more capable of dealing with flesh than ornithopods

Exhibit A: thier teeth are small but great for grinding up plants but not for chewing meat.

Exactly the other way around: their teeth don't grind, they cut. Ceratopsian jaws are like two pairs of hedgecutters. The lower jaw cannot move sideways, or even forward or back.

Exhibit B: thier beak is like scissors good for cutting off plants not meat.

I think a large number of carnivorous birds and turtles would disagree with you.

I could see mabye a dinosaur like chaoyangsaurus doing this but not a sryrac.

I don't think it's probable that large ceratopsids ate serious amounts of meat, especially in an ecosystem with tyrannosauroids and dromaeosaurids, but I don't think it can be ruled out completely...

But my personal opinion is that chaoyangosaurus of pssitacosaurus are not even related to triceratops of styracosaurus.

And what do you base that opinion on?

As a whole I think ceratopsian omnivory is undeniable, even if it was just partial as in hippos.

Well, "undeniable" is a strong word; and if you count hippos as "partially omnivorous", that's a very broad definition.

Darren said (waaay back on June 6, 2007):

though, obviously, no-one is going as far as saying that [ceratopsians] were vicious flesh-rending carnivores. That would be very silly...

Very silly indeed. And yet someone went that far and said precisely that.

It was no serious paleontologist who said it, though. It was Edgar Rice Burroughs, the author who invented Tarzan. In Burroughs' 1921 novel Tarzan the Terrible, our ape-man hero visits the lost world of Pal-ul-don, where he encounters the gryf, a fearsome, flesh-eating descendant of Triceratops.

Tarzan the Terrible is usually considered one of the best Tarzan novels (although that, to be honest, isn't saying much). The text of this novel, should someone wish to read it, is in the public domain and can be found online.

So Burroughs discovered the griffin-ceratopsian connection all on his own?

<would lift one eyebrow if I could>

Fascinating.

David:

So Burroughs discovered the griffin-ceratopsian connection all on his own?

So it would seem. But the significance of that observation, I'm afraid, is much reduced by the fact that from a scientific point of view, Burroughs' novels are a load of codswallop.

To be fair though, Burroughs did also anticipate things like hybrid speciation in that novel; the fauna of Pal-ul-don includes a saber-toothed feline species that's supposed to have originated from hybridisation between some extinct saber-toothed tigers and modern African lions. You can read more here.