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RE: Polar dinosaurs




-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
Dann Pigdon
Sent: Saturday, June 17, 2000 3:33 PM
To: dinosaur@usc.edu
Subject: Re: Polar dinosaurs

*

>... SNIP
> Large sauropods? They couldn't hibernate and weren't covered in 'fur'.

There are no sauropod remains in the extreme south of Australia, only in
the north of the country. Perhaps like crocs, they could tolerate a
certain level of coldness, but not as much as other animals (hypsies,
etc), which kept them only in the more northerly regions of Oz.<<

* Ok, the book says that sauropods are rare at the Ridge consiting of teeth.
They have some opalized caudal centra from Sheepyard, 80 km west of Lighting
ridge. I take it this means further inland. I don't think that would
miminize the cold or the long nights just because it's more inland. Wasn't
all of Australia subject to long nights?

>>The only bird evidence from the extreme south of Oz are bird feathers in
the Koonwarra deposits (formed when the shallows of a lake froze over
during the winter). The feathers are in good condition and don't look
like they had been lying around for weeks or months before ending up in
the lake. Perhaps this is evidence that some birds stuck it out during
the winter months? It would be great if we were to find bird or small
theropod fossils in these deposits. There's a real possibility of
integumentary structures being preserved.<<

Tibia found in Coocoran. I don't know how far that is from the coast.

>... SNIP
> So how did the larger animals survive the cold?
>
>
It's hard to say in the Victorian deposits. They seem to have been
formed by river deposits coming to rest. Larger material seems to have
been left behind somewhere up stream, with a bias towards the smaller,
more easily transported material. Therefore it may be hard to say with
certainty whether larger animals vacated the region during the colder
winters or not. Perhaps the "Walking with Dinosaurs" scenario was partly
right. Larger animals migrating, leaving those smaller animals, less
able to make large journeys, to endure the winter. Of course I have
trouble seeing Muttaburrasaurus getting that far south. They would have
had to cross some major stretches of open ocean to get from Victoria to
Queensland during the Early Cretaceous.<<
Right so they had to be living there all the time (or at least in
Australia).
Tracy