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Re: Triassic dino tracks in this week's Science
"Thomas R. Holtz, Jr." wrote:
> Thulborn, T. 2003. Comment on "Ascent of Dinosaurs Linked to an Iridium
> Anomaly at the Triassic-Jurassic Boundary." Science 301: 169.
> A comment on Olsen et al.'s paper last year, suggesting that a) an impactor
> is the cause of the Tr-J extinction and b) such extinction allowed the rise
> of giant theropods, among others. Thulborn discusses trackways and prints
> from Molteno Formation of southern Africa and the contemporaneous Ipswich
> Coal Measures of southeastern Queensland, Australia (both Carnian). These
> prints are big: one is 43 cm long, and thus Allosaurus-sized.
They've obviously lost some weight in the last five years. Thulborn 1998
has them at up to 46cm. See:
Thulborn, R.A. 1998 Australia's earliest theropods: footprint evidence
in the Ipswich coal measures (Upper Triassic) of Queensland. Gaia
> In response, Olsen et al. point to features of the Aussie tracks with those
> of big pentadactyl tracks from the Carnian of North Carolina
> (Parachirotherium, which may be from pseudosuchians). The latter can be
> misinterpreted as theropod tracks if digits I and V are poorly preserved.
In the Ipswich Coal Measures, they co-exist with much smaller
*Grallator* prints. Aren't *Grallator* considered by some to be a size
variant of *Eubrontes* (or vice versa)?
Dann Pigdon Australian Dinosaurs:
GIS / Archaeologist http://www.geocities.com/dannsdinosaurs
Melbourne, Australia http://www.alphalink.com.au/~dannj/