Re: Scandinavian dinos!!!....aaaaand some spinosaur stuff....

[Dann Pigdon <dannj@alphalink.com.au>]

MGibb21521@aol.com wrote:
> 
> In a message dated 97-10-07 07:07:34 EDT, you write:
> 
> << Yeah, but the Spinosaurus lower jaw, is similar to many, many other
>  theropods jaws too!!
>   >>
> I know!!  That's my point.  I don't think Baryonyx walkeri and Spinosaurus
> aegipticus are extremely similar!
> 
> And I believe that some other spinosaurs had back sails...
> possibly Altispinax dunkeri and Siamosaurus suteethorni.
> 
> I'm not saying that sails were common to the group, however, it was probably
> a climactic factor, because a hadrosaur from the same Egyptian deposits as
> Spinosaurus had a sail similar to Spinosaurus's.
> 
> And I'm also not saying that Baryonyx and Spinosaurus weren't the slight bit
> related, because they were.  Baryonyx probably led to later Cretaceous
> predators like Spinosaurus and Spinosaurus had the sail because of some
> climactic feature during late Cretaceous in Egypt.
> 
> Chandler Gibbons
> Arvada, Colorado
> MGibb21521

        I'm not sure that we can immediately assume that sails were
thermo-regulatory. They are a bit like the counter-balance claims
for pterosaur crests: closely related species seem to get by without
them. Simiarly, many theropods lacked dorsal sails, as did many
sauropods and ornithopods that lived in similar conditions to the
sailed varieties. The co-occurance of spinosaurs and ouranosaurs may
just be a coincedence of fossilisation.
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        Dinosaur Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        Australian Dinosaurs:
        http://www.alphalink.com.au/~dannj
____________________________________________________