Klaus Ebel's aquatic Saurischia

["Nicholas Gardner" <ratites637@hotmail.com>]

--- 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.
>
> http://www.ebel-k.de/dinosaurs1/dinosaurs2/dinosaurs2.html
>
> 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He also presents outdated reconstructions of both _Ouranosaurus_, 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)

GAH!

Nick Gardner

_________________________________________________________________
Protect your PC - get McAfee.com VirusScan Online  
http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963