[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: 45 MYA Redwoods Found Near North Pole

David Marjanovic wrote:

> Permafrost!?! Really? Cool... :-)
> *Leaellynasaura*, named after Rich's daughter Lea Ellyn.

Actually, the type specimen of L.amicagraphica is from the 106 MYA Otway
Group deposits (Dinosaur Cove). The permafrost deposits are in the 115
MYA Strzelecki Group deposits near Inverloch (although Leaellynasaura
sp. has also been identified from this area). The permafrost deposits
are of a slightly different date to those that yeild fossil material.
Palynological studies (part of a long-going research program) seem to
indicate that close to the permafrost layers, ferns seem to dominate,
with few if any pollen from tree species. A fern tundra environment has
been suggested at the time. Unfortunately I don't think any actual
pollen or spores have been recovered from the actual peramfrost layers,
only either side of it.

Since no fossils are directly associated with the permafrost layers
themselves, it is always possible that these indicate an even colder
period than usual, during which dinosaurs may not have been present in
the area. Of course they COULD have stayed around, but there is no
evidence for it. Not that the environment wouldn't have been cold (or
hostile) enough during the times represented by fossil bearing strata.


Dann Pigdon                   Australian Dinosaurs:
GIS Archaeologist           http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://www.alphalink.com.au/~dannj/