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Re: Spinosaurs as what?
Tim Williams wrote:
Before you go too much further with this, I would caution that not
everybody is so keen on the idea that spinosaurids spent most of their time
in water catching fish.
And I want to scare those persons up so they can have a say on my
meanderings. And thanks for the info and references :-)
Sues et al. (2002) point out that the long narrow snouts of spinosaurids
and piscivorous crocodilians (e.g., gavials) are actually rather different.
Spinosaurids have flat-sided snouts that are convex on top, whereas the
snouts of fish-eating crocs are more tubular.
Much like any Ciconiidae (flightedness nonwithstanding) and storks don't
only eat fish ;-) ( http://en.wikipedia.org/wiki/Stork ).
Sues et al. (2002) suggest that this morphology, like the extensive
secondary palate, rendered the spinosaurid snout less susceptible to
bending stresses, and was not a piscivorous adaptation per se. They also
suggest that the shape of spinosaurid teeth (conical or only weakly
recurved) are "consistent with their use for impaling and holding prey".
All in all, they suggest that the jaws of spinosaurids were adapted for
seizing small prey. The authors conclude:
Interesting... _Lepidotes_, the fish found with _Baryonyx_ had what size
[snip] Most likely spinosaurid theropods rapidly and forcefully seized
smaller prey, which was then processed by dorsoventral motion of the head
facilitated by the powerful neck musculature. [snip] Previous anatomical
comparisons between the feeding apparatus of crocodylians and spinosaurid
theropods were based only on superficial resemblances.
The postcranial skeleton of _Baryonyx_ lacks any obvious specializations
suggestive of an aquatic or semiaquatic mode of life (Charig and Milner,
My thoughts exactly! But I do like playing devil's advocate, if the list
members don't mind, that is. But still what function had their big thumb
claws? Are they just a result of the scaling up their bodies suffered while
evolving? Are they display devices or means for some not yet forseen
Also, don't forget that there is evidence that pterosaurs were also part of
the spinosaurid diet. The remains of one pterosaur were found with a
spinosaurid tooth embedded in its neck vertebra.
Yes, and I think the only way the tooth could have gotten wedged there would
be if the spinosaurid was specifically trying to capture the pterosaur.
Whether it was predation or just eliminating a nuisance is open to
P.S.: If you don't mind I'd rather reply to the list than to have two or
more emails with the same content if I reply to each person individually.
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