Re: Dinosaurs survived in Antarctica? (Was: Re: "Dinosaurs Died W ithin Hours After Asteroid Hit Earth...")

[Brian Choo <bchoo@bigpond.net.au>]

Hey there

On 20/06/2004, at 3:18 PM, K and T Dykes wrote:
> The sloth's at Seymour Island along with gondwanatherians and a rhea,
> (Eocene).  The presence of monotremes (Monotrematum) in the Paleocene 
> of
> Patagonia suggests immigration.  Monotremes are otherwise only known 
> from
> Australasia since the Lower Cretaceous.

And in the Late Paleocene Tingamarra fauna from Queensland we get a 
whole host of of stuff that is more characteristic of a South American 
(or rather a pre-breakup gondwanan) fauna but subsequently went extinct 
in Oz - notably salamanders, trionychid softshells, microbiotheriid 
marsupials, a possible ameridelphian opossom (Djarthia),  the eutherian 
Tingamarra etc.

Michael wrote:

>Where are the australian Eutheria / Xenarthra?>>

Well, xenarthra is unknown but we do have an ozzie Paleocene 
"condylarth" in the form of Tingamarra. And of course if the Riches are 
right, Australia has had eutherians since the Aptian...  As to where 
the Australian Eutheria went - well we have a complete gap in the 
vertebrate fossil record between the very scant Late Paleocene (where 
we do have terrestrial eutherians plus bats) record and the excellent 
Late Oligocene Riversleigh sites (where we don't have terrestrial 
eutherians - although the bats are still there) so anything goes in the 
c.20 million year gap. Since Australia was pretty much next to ground 
zero with regards to the climatic turmoil that struck the Late Eocene 
world one might expect some tough times for it's critters around then.

Cheerio
Brian