Dinosaur Dreaming report 1999

[Dann Pigdon <dannj@alphalink.com.au>]

I was at the annual "Friends of Dinosaur Dreaming" talk last night,
which included talks on the 1999 field season at Flat Rocks,
in south eastern Australia. Topics included excavation techniques
(in the tidal zone no less), an overview of the fossil finds and
research so far, and studies of the taphonomy of the site.

The 1999 season saw three more mammal jaws being unearthed (or
unrocked). Two of them seem to belong to the Ausktribosphenos
genus, the other may be but is more doubtful. This brings the total
Ausktribosphenos material to seven jaws so far. It seems that
Ausktribosphenos (can we call it "Oscar" for short, or do I have
to keep typing it all out?) may turn out to be a proto-hedgehog
(or is that proto-proto-hedgehog) of the genus Erinaceidae. That's
sure to ruffle a few feathers (erh... hairs?) since the prevailing
theory is that placentals developed in the Northern Hemisphere
and eventually spread south. Apparently the paper:

  Rich, Vickers-Rich, Constantine, Flannery, Kool and van Klaveren
  1999 "Early Cretaceous mammals from Flat Rocks, Victoria,
  Australia". Records of the Queen Victoria Museum 106:1-35

suggests that they may have ridden north on microcontinents as they
peeled off the northern edge of Eastern Gondwana. Yet more evidence
of supposedly Northern Hemisphere animals appearing in the south
earlier than elsewhere.

Also discussed in brief was the new mammal Teinolophos trusleri
(named after palaeo-artist Peter Trusler), which was discussed in
the same paper mentioned above. It seems to have been a eupanothere,
the first known from Australia.

Within the next month or so you can expect the description of
Qantassaurus intrepidus and the second (and highly revised)
edition of "Wildlife of Gondwana". The type specimen of Qantassaurus
is a nearly complete dentary with only 12 teeth (as compared with
14 or more for most hypsies), suggesting a slightly shorter, deeper
face than usual. At least three jaw specimens have been found
so far (and as it turned out, I've had a cast of the type specimen
for years).

A Russian expert on permafrost has confirmed that rock formations
near the Flat Rocks site are almost certainly evidence of
permafrost-related cryoturbation. Unfortunately the sediments
are about 3 metres below those of the main fossil bearing layers,
so they're not contemporaneous. Palynological studies have begun
in earnest, and strangely enough pollen seems to be present only
in the cryoturbated layers, with not a single grain being found
above or below that particular layer. So far ferns and ginkophytes
have been identified, although no pine or araucarian pollen has yet
turned up. Bits of fossil wood are being studied to see if the growth
rings reveal strong seasonal growth fluctuations. It seems that
the weight of evidence is so far pointing to dinosaurs living
in polar conditions.

A huge hypsie femur (21 cm long) was found in the 1999 season.
It's starting to look like there was an unusually wide range of
hypsie species down south. They are discussed in the paper:

  Rich and Vickers-Rich 1999 "The hypsilophodontidae from southeastern
  Australia". In Tomida, Rich and Vickers-Rich (eds), Proceedings
  of the Second Gondwanan Dinosaur Symposium. National Science
  Museum Monographs No 15: 167-180

Also some more isolated theropod material (an ungual, some teeth),
a possible monotreme tooth fragment (assumed monotreme for now
based on its large size), and a possible mammalian incisor fragment.

-- 
____________________________________________________
        Dann Pigdon
        GIS Archaeologist
        Melbourne, Australia

        Australian Dinosaurs:
        http://www.geocities.com/capecanaveral/4459/
        http://www.alphalink.com.au/~dannj
____________________________________________________