Re: Swiming spinosaurus

["Steven Coombs" <gasperex@hotmail.com>]

So is there anything else done on other animals much older than the
dinosaurs as Dimetrodon and Edaphosaurus, and do these animals have neural
arches similar to Spinosaurus (And others) and biffaloes? Because they are
to been seen as having a sail on there back as well. Animals like
Rebbrachiosaurus, Ouranosaurus and also Barsboldia, these animals are
bacically quadruped while Spinosaurus and Acrocanthosaurus are bipedal. Why
for exmaple we get other Spinosaurids such as Baryonyx which does not have a
sail on its back. In Suchomimus it has tall neural arches about half the
lenght as Spinosaurus, it seem that it evolved in time.

Steve


> From: "Mickey Mortimer" <Mickey_Mortimer11@msn.com>
> Reply-To: Mickey_Mortimer11@msn.com
> To: <dinosaur@usc.edu>
> Subject: Re: Swiming spinosaurus
> Date: Tue, 10 Jul 2001 08:50:25 -0700
>
> Steven Coombs wrote-
>
> > I heard and read about the "hump theory", and I do find somethings wrong
> > with this theory, how could an animal have something like this on its
> back.
> > There would be too much weight distributed on the back of the animal,
> the
> > animal would be a struggleing with it whnever it moved! From the remains
> of
> > the neural arches they were quite slender(It would be really imposible
> to
> > hold it up much), and if it did have a hump, would it be more plauseable
> > that it would have had air-sacs just like some giant Sauropods such as
> > Sauroposeidon in there neck, to take off a bite of the weight? And why
> do
> > they bring this up more on Spinosaurus than other animals presumed to
> have
> > sails such as Ouranosaurus, and it lived on the same continent as
> > Spinosaurus and the same type of environment? Aleast Ouranosaurus has
> > remains while Spinosaurus remains just dust!
>
> I strongly suggest you read Jack Bailey's (1997) paper on the subject.  He
> performed biometric analyses showing the spines of most sail-backed
> dinosaurs are similar to those of humped mammals, mostly artiodactyls.
> This
> means the narrowness is not an issue.  Remember that most theropods were
> rather laterally compressed, so the hump would not have been much more
> hindering than the whithers of a bison (which in some extinct species like
> Bison antiquus actually equals Spinosaurus in neural spine height).  Of
> course, Spinosaurus was probably bipedal, but it could have had very robust
> limbs, an elongate tail for counterbalance, or even have been partially
> quadrupedal, as spinosaurids do have robust and elongate forelimbs.  Bailey
> examines all types of humped dinosaurs, including Spinosaurus,
> Acrocanthosaurus, Rebbachisaurus, Ouranosaurus and Barsboldia.
>
> Bailey, Jack Bowman, 1997, Neural spine elongation in dinosaurs:
> sailbacks or buffalo-backs?:  Journal of Paleontology, v. 71, no. 6, p.
> 1124-1146.
>
> Mickey Mortimer

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