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Re: Spinosaurus - the authors respond

That'd be some penguin....

Ronald Orenstein 
1825 Shady Creek Court
Mississauga, ON
Canada L5L 3W2

> On Sep 19, 2014, at 10:57 AM, Tim Williams <tijawi@gmail.com> wrote:
> The case for the affirmative...
> http://www.skeletaldrawing.com/home/aquatic-spinosaurus-the-authors-responsd9182014
> It's also worth mentioning that evidence of an aquatic _Spinosaurus_
> refutes a hypothesis put forward in the 1990s that non-avian theropods
> were 'limited' in the potential niches they could exploit (including
> aquatic/marine habitats), because they only possessed a single
> locomotor 'module' (hindlimb + tail). By contrast birds, with three
> separate 'modules' (wings, hindlimbs, tail) were far less constrained.
> It is true that birds have exploited far more diverse ecological
> niches than their non-avian counterparts... but the hypothesis that
> non-avian theropods were anatomically precluded from becoming
> semi-aquatic has been dealt a blow  by _Spinosaurus_.  I'd also be
> surprised if _Spinosaurus_ was a 'one-off' in this respect.
> This same hypothesis also proposed that the hindlimb of non-avian
> theropods could not undergo any major modifications (such as for
> aquatic locomotion) without severely compromising terrestrial
> locomotion.  This would appear to hold water (so to speak).  In an
> imponderable 'what if' of evolution, spinosaurs could have given rise
> to obligate aquatic/marine predators similar to thalattosuchians or
> mosasaurs or even penguins.
> Cheers
> Tim