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Klaus Ebel's aquatic Saurischia

--- Brian Choo wrote:
K. Ebel's work on the aquatic origins of bird-flight have been discussed
previously on the list. Been checking out his website and I see that he has
gone a few steps further - he now seems to be claiming that the entire
Saurischia were, for the most part, water-dwelling animals - sauropods,
tyrannosaurs, ornithomomimes, dromaeosaurs - the whole boatload, based
primarily on the morphology of vertebral processes. Er...better just read
it for yourselves.


Still, it was nice of him to create such easily accessible archive of all
his biomechanical work (hard-copies of which I've had major difficulties in
tracking down) on the web.

I am speechless.

I think the principle error throughout the paper stems from that Ebel is trying to insist that because the adaptions for terrestrial locomotion in >> QUADRUPEDAL << ungulates and the freakish pseudosuchian _Ctenosauriscus_ (tall neural spines of the anterior dorsal vertebrae) were absent in theropods, this indicates that they could not have been terrestrial locomoters. I'm going to go out on a limb and make a few comments.

Aren't tall neural spines in the anterior dorsal region in ungulates an adaption related to that they are putting more stress on their forelimbs in locomotion? I do not see how it compares to bipedal theropods, which did not need to have structures designed to within stress in regards to their forelimbs. How does Ebel deal with terrestrial squamates and pseudosuchians that were not aquatic and lack tall neural spines? Or that the neural spines were elongated in many sauropod taxa . . .

He also presents outdated reconstructions of both _Ouranosaurus_, _Dilophosaurus_, _Deinonychus_, _Amargasaurus_, _Dicraeosaurus_ and _Camarasaurus_. As well as splitting Theropoda into the archaic division between coelurosaurs and carnosaurs (which he evidentally considers _Dilophosaurus_ to be).

He also evidentally regards _Ctenosauriscus_ as bipedal. The only similiar statement I can think of in published papers is that Chatterjee promoted the idea of a bipedal _Postosuchus_.

Ebel fails to address features discussed by Holtz and others as adaptions for terrestrial locomotion (i.e. arctometatarsus).

In table 1, there are several errors. There are some sauropods with armor (i.e. _Saltasaurus_). What does armor have to do with a terrestrial lifestyle? What about crocodiles and turtles, which also have armor of some sort or another? He fails to note that not all ornithischians have hoof-like feet (consider small ornithopods, etc.). He doesn't note that dromaeosaurids had ossified tendons. And doesn't note the differences in many theropod taxa from the basalmost dinosaurs as far as pelvic morphology is concerned.

He also evidentally never got around to reading Bakker 1986 as he does not cite it . . . (sarcasm yes, I realize that no one cites every single paper they read)


Nick Gardner

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