Tetrapod Zoology

Today I had good reason to send to Markus B�hler – my good friend and an avid Tet Zoo supporter – several images of entelodonts. What the hell, I thought, why not share one of these images with the rest of you. This awesome life-sized model depicts the Oligocene-Miocene North American entelodont Daeodon (formerly better known by its synonym Dinohyus) and is on display at the Denver Museum of Nature and Science. It’s a shame there’s no scale in the photo: Daeodon was huge (c. 1.8 m tall at the shoulder). The model is fantastically accurate: it even has snot in its nostrils.

As was previously mentioned in the POTD article on omnivorous ceratopsians, it’s quite well known that entelodonts are widely regarded as omnivores, as is indicated by their pointed incisors, recurved, pointed, serrated canines*, serrated premolars, unusually mobile** jaw joint, and by studies on bite strength (Effinger 1998, Joeckel 1990). Oh yeah, and there’s the discovery of a pile of bitten-in-half little stenomyline camels, the marks on their bones matching the anatomy of entelodont teeth. Massive bony cheek flanges and bony tubercles on the lower jaw might have been used in intraspecific fights, and some specimens preserve skull injuries apparently inflicted by other entelodonts.

* The canines were serrated in juveniles, but the serrations generally became worn away during ontogeny.

** Unusually mobile for an artiodactyl that is.

i-a3c6f00504d66fbbdcc40b216f9b1e44-entelodont skull.jpg

The postcranial morphology of entelodonts is remarked upon less often. Even giant forms had a surprisingly gracile, slender neck, but big neural spines on the anterior thoracic vertebrae show that very large nuchal ligaments were present: the anterior thoracic neural spines of Daeodon are almost on par with those of bison and other tall-spined ungulates. Entelodonts were strongly cursorial, with elongate and slender limbs where the radius and ulna, and tibia and fibula, are often fused together. Unlike anthracotheres and pigs, entelodonts were didactyl. Not only were they nasty and with a frightening dentition, they were also fast! More on them one day in the future.

Entelodonts may or may not be suiforms, but for Tet Zoo ver 1 articles on extant suiforms check out: welcome to the world of babirusas, the many babirusa species, meet peccary # 4 and why putting your hand in a peccary’s mouth is a bad idea.

Hmm, that was less of a ‘picture of the day’ and more of a ‘post of the day’.

Refs – -

Effinger, J. A. 1998. Entelodontidae. In Janis, C. M., Scott, K. M. & Jacobs, L. L. (eds) Evolution of Tertiary Mammals of North America. Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals. Cambridge University Press, pp. 375-380.

Joeckel, R. M. 1990. A functional interpretation of the masticatory system and paleoecology of entelodonts. Paleobiology 16, 459-482.

Comments

#1 Phil Hore
July 11, 2007

Wonderfull animals these, I’m always amazed we don’t hear more about them…along with the gorgonopsids and the monsterous brontotheres. thanks for the image, just saw a smaller skull at the Natural History Museum in London, and that was impressive so the larger species must be awesome…always reminds me og a hippos skull.
one thing, if not suiforms, what might they be?
#2 Warren B
July 11, 2007

Excellent! I’m fond of these beasties, and I’m trying (key word: _trying_) to sculpt a small-scale Daeodon myself. It’s always good to get any new reference – and to see that my own tortured reconstructions aren’t too far off the marks of others.
#3 Zach Miller
July 11, 2007

Now here’s my question about these big “pigs.” I know that their ancestry is debated, but what are the competing theories regarding it (aside from the suid association)?
#4 R. A. Wilderson
July 11, 2007

It’s a pity you can’t see the entire diorama. The entelodont in question has speakers and emits the occasional grunt. On the other side of the display (the human visitors stand in the center on a small path) there is a small herd of fleeing camelids of some sort.
#5 Raymond
July 12, 2007

Daeodon!Entelodonts!!!!!!More!MORE!!!!!!Entelodonts,Multis and Cenozoic Sebosuchids.

btw, Cameron McCormick beat you to the choristodires.

“More on them one day in the future.”

All hail Lord Naish (kowtows)
#6 Mike
July 12, 2007

I’m not sure I want more on Entelodonts. They are seriously scary things and one of the few ancient critters I’m really happy are extinct. There’s just something inherently affronting about the prospect of being eaten by something soooo ug-ly.
#7 johannes
July 12, 2007

Entelodonts ! Please give us more! More predatory ungulates in general! Mesonychids! Triisodonts! Pakicetus!

> They are seriously scary things and one of the few ancient critters
> I’m really happy are extinct.

Any creature that could be a serious match for armed humans is well worth reading about, especially if its a predator (applies also for Arctodus).
#8 Sordes
July 12, 2007

Thanks for the info about supporting evidence for carnivory in entelodonts. I really had doubts that the idea of a carnivorous monster-boar could be right, especially because the teeth of the model I saw, look very strange (and in fact different from the skull on the upper image).
The photo of this model can be seen here: http://bestiarium.kryptozoologie.net/?p=59
It is much lesser nice than the Daeodon from Denver, and in fact it looks nearly identical to the entelodons from “Walking with Prehistoric Beasts”. It was part of a big exhibition of prehistoric mammals (and some birds) which was not in a museum or open air park, but on different places within a town. It was very cool to see those critters in life-size, for example a huge Deinotherium or Indricotherium (which looks in realitiy much smaller than in books with size comparisons).
#9 Dave Hughes
July 12, 2007

Entelodonts are seriously impressive animals. One thing that I find puzzling about them is why they didn’t last longer. Big, fast, omnivorous, opportunistically predatory, presumably fierce and aggressive – sounds like a recipe for success to me. From what I’ve read there are fossils from across Europe, Asia and North America, so they were clearly adaptable and successful in their time. You would think with the spread of grasslands during the later Miocene they would have done very well, but they obviously had an Achilles heel somewhere. I find it fascinating to speculate about why particular taxa survive and others don’t – there often seems to be no rhyme or reason to it. I wonder whether they had a pig-like reproductive strategy with large litters, or a more typical large mammal arrangement of one young at a time? I imagine a lucky fossil find of a pregnant female might give us an answer to that question one day.
#10 chris wemmer
July 12, 2007

May I add that they obviously had powerful front-wheel drive, and possibly a loping gait like Connochaetes or Hippotragus. I like the artist’s addition of the crest, as “hair displays” are part of the “schtick” of tropical suids, and might have been with entelodonts too. It would be surprising if they didn’t have dermal shields on the shoulders and neck. Those tusks were no doubt used for slashing and bashing, even if the heads were engaged in frontal shoving matches. As for reproduction, I would guess their young were relatively precocial. Obviously paleo-artists have to know a good deal about ecology and behavior or contemporary species if they are going to use their artistic license with credence. Nonetheless its great fun speculating about species that capture your imagination so easily. Onward and upward. What’s next, Darren.
#11 Darren Naish
July 12, 2007

What’s next, Darren.

Iguanas.
#12 Tengu
July 12, 2007

When I was a child, I was told that monsters were not real.

…They then took me to the NHM, It was a truly epithianic (is there such a word?) experience.

I have loved prehistoric animals ever since.
#13 Tegumai Bopsulai, FCD
July 12, 2007

Iraq badger attack
#14 Diego
July 12, 2007

Darren, I’ve got a quick question. I haven’t been to your site in a while and I recently noticed that the banner at the top of the page seems to be new. Is that a green anole in the banner?

[from Darren: it's two Green anoles. They're mating - the larger male is to the left. Ha - graphic sex in my banner!]
#15 David Marjanovi?
July 13, 2007

epithianic (is there such a word?)

Do you mean you had an epiphany?
#16 Tengu
July 14, 2007

Yes. Do you think that is the right way to express it?
#17 Jerzy
July 16, 2007

I wonder if teeth of entelodons really are evidence of any carnivory…

Wild boar has remarkable canines, warthog really crazy ones, macaques and langur males have caninces as leopards, but it is only intraspecific fighting.

[from Darren: please re-read the article. The idea of carnivory in entelodonts is not based on big canines alone]
#18 Sordes
July 29, 2008

I just wanted to add that I found some time ago photos of bones of a chalicothere-like animal with bite-marks of entelodonts.