Wednesday, November 27, 2013

Species that don't get publicity #4: Pristichampsus sp.



This featured genus is not a dinosaur. It’s been mistaken for one in terms of teeth, but it is not a dinosaur.  It did live in the same ecosystems as a big terrifying theropod, but not a dinosaur. I wouldn’t call it entirely obscure as it has appeared in some reference works and even a TV show, but no documentaries yet, let alone films. This is really too bad, as it’s a pretty terrifying concept: a crocodile with long legs and curved, serrated teeth.




Pristichampsus is the genus, with the species P.vorax from the United States, P. rollanti from Germany and P. birjukovi and P. kuznetzovi from Kazakhstan. Now, this may not be the case, as C.A. Brochu has just come out with a paper arguing that Pristichampsus is a nomen dubium and that the material should be reassigned to Boverisuchus, previously synonymized http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9036311. The dust is still settling and I’ve seen no papers arguing for or against Brochu’s position, so for now I’ll just keep the standing taxonomy.
To make the naming easier, it might be better to use a common name. In Robert T. Bakker’s classic book The Dinosaur Heresies, he refers to them as Panzer Crocs, and has a fantastic illustration of one ripping into an Eohippus at full gallop.  Yes, I said gallop. Panzer crocs are unique-instead of flattened tails for swimming, they had thin, rounded tails for balance. Instead of splayed, curved claws on short limbs, Panzer crocs had long limbs with blunt hooflike claws. These suggest that this animal was a runner. 


Crocodiles do run from time to time.  As ectotherms, they can only move quickly for short bursts, but at impressive speeds. Saltwater crocodiles, the largest species of crocodile, can hit 11 miles per hour. Crocodiles have three kinds of running: belly run, a fast walk using the standard splaying stance, the high walk, placing the legs closer together and raising the body off the ground, and the gallop, bounding with alternating front and back jumps like a rabbit.. http://crocodilian.com/cnhc/cbd-faq-q4.htm. Pristichampsus would probably run faster, maybe even as fast as an Olympic sprinter 


The other main difference is the teeth. All crocodiles today have conical teeth, for piecing fish scales and turtle shells. These teeth are relatively unspecialized, and this allows them to eat basically any kind of animal they can catch and subdue.  Pristichampsus is different; its teeth are called xiphidont or sword shaped. They have curved, serrated teeth, laterally compressed to a sharp edge for slicing through flesh. When teeth have been discovered without the rest of the animal, some palaeontologists thought of it as evidence that theropod dinosaurs had survived the K-Pg extinction.  It must have been a surprise to find them in the mouth of a crocodile. Interestingly enough, like big carnivorous birds, this evolved in both Laurasian and South American crocs. Ziphidont crocs in the south were sebecoids, except for the Australian Quinkana which I mentioned during my Australia list.
The teeth and hooves point to one conclusion-this crocodile was a terrestrial predator specializing in the land mammals of the day. Most of them were small but fast, and this 10-foot croc could easily overpower most prey. Only the giants like pantodonts and Gastornids could possibly stand up to an attack. With the extinction of the dinosaurs, different animals competed for their roles .In the terms of large land carnivores, it was the birds and the crocodiles that first came up to bat, only becoming extinct with the arrival of the Creodonts,  fast-breeding mammals that could hunt for prey more efficiently.



Along with Gastornis, Pristichampsus was the top predator in the Palaeocene and early Eocene of Laurasia. Pristichampsus specimens have been found in very good condition in the Messel Pit in Hesse, Germany, alongside early bats like Palaeochiropteryx, ungulates like the goatlike Messelobunodon and the tiny horselike Propalaeotherium, pangolins Eomanis and Eurotamandua, small  creodonts such as Lesmesodon, primates Godinotia and Darwinius, more typical crocodiles like Asiatosuchus, and flightless birds like Palaeotis, all of which would have been possible prey for this predator. 




Unlike its rival Diatryma/Gastornis, Pristichampsus never grew to such popularity. Only in the recent years has it made even a cameo in the popular culture.  One is that it has recently been included in Safari Ltd’s excellent prehistoric crocodiles “Toob”, despite being in a small, relatively simple sculpt. The other appearance was in the BBC sci-fi series Primeval, where two rampage around the British Museum’s Egyptian exhibit before being dispatched by the main characters.  Like the toy, it is crude in compared to the more elaborate effects in documentaries.  When Walking With Prehistoric Beasts, another BBC program, explored the Messel fauna, the top predators were Gastornis and Ambulocetus, not Pristichampsus. Like the genus in the evolutionary race, it seems to have very little luck making an impression and only the briefest of attention.



You would think a galloping, knife-toothed crocodile would be terrifying enough, chasing down horses, rampaging around the tropical swamps of Palaeogene Germany and the American West, perhaps even having tense confrontation with the bear-like terror bird rival. 

So anyway, Hollywood, give this guy a break. Museums, keep him on display and show him outside one particular museum (http://www.geiseltalmuseum.de/). Toy companies, here’s a new fresh face. Authors, think about the crap you’re writing and how this genus could perk up the place. And remember, shop Pristichampsus where you work or play. 

Here’s a short writeup from the excellent blog “The Forgotten Archosaurs”
http://forgottenarchosaurs.blogspot.com/2010/07/pristichampsus.html

7 comments:

  1. "Along with Gastornis, Pristichampsus was the top predator in the Palaeocene and early Eocene of Laurasia."
    Sorry to sound like a know-it-all, but didn't a guy called Thomas Tütken give good evidence that the Gastornis was in fact a herbivore? I'm not an expert in the field and I have to rely on the accounts of others, so what's up?

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    1. I've read the article. It's based on isotope material. The problem is that beaks don't preserve isotopes as well as teeth, and the announcement came after only one scan without subsequent checks or comparisons with other birds. I'm still doubtful of herbivory. All herbivorous terrestrial birds have small head. So if Gastornis was eating plants, what kind of plants are we talking about? Did the Eocene have nuts the size of basketballs?

      I think it was an omnivore-big, generalized, and powerful jaws that can eat most anything. A lot of birds today are omnivores, and I could see Gastornis being the bear of the Eocene

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    2. You could be right - after all, I'm not really an expert, just some guy who likes to read this stuff. However, this article here makes a good case about big bills and herbivory (but again, I'm not an expert): http://gwawinapterus.wordpress.com/2013/12/15/herbivorous-flightless-birds-and-their-big-heads/

      Anyhoo, ever since I saw an illustration of a Gastornis gobbling down branches (with leaves, fruits and all), I'm beginning to imagine the bird as a pruning machine for the paleocene/eocene forests, carefully evading the attentions of the aforementioned terrestrial crocs, who perhaps could have developed extra armor due to the weight of Gastornid beaks.

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  2. Oh, and I forgot to ask about the Arctocyon. What would it do?

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    1. Are you referring to the Andrewsarchus-Arctocyon connection? Arctocyonids are generalized omnivorous Paleocene animals. They might be related to both aritodactylids and whales.

      Here are two articles on the issue
      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2740860/
      http://palaeo-electronica.org/2011_3/3_clemens/



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    2. Here's an excellent blog post on Andrewsarchus, Arctocyon, Mesonyx and the jumble at the base of the ungulate family tree.

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    3. I was actually wondering what the Arctocyonids would do in relation to the Gastornids and the crocs. I have this book illustrated by Mauricio Anton that says that the Arctocyonids were the largest mammals of the paleocene.
      And thinks for the article.
      I hope I haven't been too annoying.

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