Geoscience Reference
In-Depth Information
The two tracks from 105-millionyear-old rocks west of Melbourne—Knowledge
Creek and Skenes Creek—were attributable to small ornithopod dinosaurs, like
Leaellynasaura
. Large-sized theropods, about the size of a smaller version of
Allo-
saurus
,likelymadethetwo115-million-year-oldtracksinrockseastofMelbourne.
None of these tracks were preceded or succeeded by another track made by the
same dinosaur, which meant, unlike many other places in the world, including in
Australia, Victoria had no known dinosaur trackways like ones at Lark Quarry in
Queensland or Western Australia.
This is where someone in the know about such things might ask, “What about
other dinosaur trace fossils?” As covered before, there were supposed dinosaur
burrows from Knowledge Creek, and that was it. No dinosaur nests, gastroliths,
stomach contents, or coprolites have been interpreted from the Cretaceous rocks of
southernAustralia.Ihadheardfromafewpaleontologiststhatsomeofthedinosaur
bones from this area had theropod toothmarks on them, but these were apparently
rare too. No one had even done a study on tooth microwear. Although there seemed
to be a good number of invertebrate trace fossils, I was traveling in uncharted ter-
ritory for dinosaur trace fossils, an ichnological analog to “The Ghastly Blank,” an
endearing term applied to the desert interior of Australia.
In contrast, dinosaur bones—most of which had been found by many people
working with Tom and Pat during the past thirty years in this part of Aus-
tralia—indicated a more diverse fauna was there than this apparent lack of trace
fossils might suggest. Moreover, these dinosaurs should have at least been leaving
tracksonsoftsandsandmudsduringthespringsandsummersinbetweenharshpo-
larwinters.Yetthesetracksseemedtobehidingfrompaleontologists.Wedealwith
gaps in the fossil record all of the time, but this was a big one for the fossil record
of polar dinosaurs in Australia.
Back to the Cretaceous Again
All of this paleontological history was running through my mind and was why I
tried to temper any anticipation during our excursion along Milanesia Beach. Yet
