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Re: Antarctica...how cold?
Lystrosaurus is known from early, early middle Triassic rocks in
Antarctica. The early Permian rocks in the Transantartic Mountains contain
many sediments suggesting the presence of glaciation, including
diamictites...etc.. then suddenly in the middle to late Permian there is a
vast change to coal measures and sediments full of Glossopteris and
Gigantoperis. Volcaniclastic are also prevailient in the Late Permian
sections due perhaps to a large island arc system of of the East Antarctic
Although there are no Late Triassic vertebrates known from the
Late Triassic of Antarctica that I am aware of, the environment was right
for them. Transition of the Transantarctic Basin to a foreland setting,
rapid subsidence and sediment accumulation in a braided stream system was
Coal measures and numerous Palynomorphs show the area still possessed a
seasonally warm climate.
There are Jurassic dinosaurs known from Antarctica, the large
theropod Crylophosaurus (sic?), also I believe two smaller unknown
theropods were found, (I'm writing this without notes in front of me, I
can give references later.) As for the Cretaceous there is an Ankylosaur
known from the Antarctic Peninsula.
So, the climate and setting was right for dinosaurs, there is a,
albeit small, Triassic, Jurassic, and Cretaceous record, so were there
Pterosaurs on Antarctica? Most likely, except that we are looking at the
incompleteness of the fossil record, especially in Antarctica where there
is less than 2% outcrop exposure.
By the way the current Antarctic Ice Sheet did not form until the
Oligocene so there should be an early Tertiary record as well. Bring on
the Greenhouse effect! Let's melt that cap!
Hope this helps
Department of Geology
Northern Arizona University
Flagstaff, Arizona 86011
On Sat, 11 Dec 1999, Larry Febo wrote:
> How cold was antarctica in the mid-late Triassic?
Lystrosaurs were found there from the (late Permian???),..no?
And dinosaurs were found that must have at least migrated
through there also
(Jurrassic-Cretaceous?). Could someone clarify these time frames?
> What sparked me off was a statement by Wellnhofer in his
Pterosaur book (pg 9 under diagram of fossil distribution)...
"The distribution of fossil finds indicates that pterosaurs
once lived on all continents except Antarctica."
Is this just poor phrasing due to translation probs,
or is he indicating that (statistically),
there is indication that there really were
no Pterosaurs in Antarctica?
Was it just too cold for them, even at that earlier time?
The earlier pterosaur finds do seem to be grouped
around the equatorial region (for the Triassic)....Just how cold was it?