WEST KIMBERLEY PLACE REPORT - Department of Sustainability ...

could have stood as tall as 5.4–5.6 metres at the shoulder and may have been up to 30
metres long (Gibson 1997; Thulborn, pers. comm. 2009). While some of these tracks
appear to be similar to the ichnogenus Brontopodus, there are three or four other types
of tracks which suggest the presence of multiple sauropod taxa (Thulborn et al. 1994;
Thulborn 1997). Also found here are the world's smallest sauropod tracks, indicating
a broader population sample than that of any other sauropod track sites known
worldwide. Further, some of the trackways are quite unusual in that there is a
disparity in the width of front and hind limb stances, indicating a previously unknown
sauropod gait. Other, exceptionally well-preserved tracks have provided the first
evidence of manus ('hand') claws in sauropods and some even preserve skin
impressions (Thulborn 2009).
Dr Giuseppe Leonardi, an Italian vertebrate palaeontologist and ichnofossil expert,
has described the Dampier Coast as a 'plant eaters' paradise' (Gibson 1997). Evidence
for the coexistence of sauropods and ornithopods, both herbivorous dinosaurs, is rare
in the world and unknown elsewhere in Australia. But it is not uncommon on the
Dampier Coast to find sites where tracks of both types of animals occur in the same
stratigraphic layer in relative abundance. In Dr Leonardi's experience of field work in
Europe and South America, carnivorous therapod dinosaurs are considerably more
common than they appear to be on the Dampier Coast. Such important behavioural
and population data underpins the scientific significance of the Broome Sandstone
(Gibson 1997; Thulborn 2009).
The Cretaceous dinosaur fauna of Australia is known almost entirely from sites on the
east side of the country. Flat Rocks and Dinosaur Cove in Victoria, Lightning Ridge
in New South Wales and the Winton Formation in Queensland have produced most of
the body fossils found. Some are known from the opal fields of South Australia;
Andamooka and Coober Pedy have produced isolated dinosaur bones. Very little is
known about the western half of the continent, which was separated from the east by
shallow inland seas. The Dampier Coast is the only site with extensive evidence of
western Australian dinosaurs. The only other evidence of dinosaurs in the west are
fragments of bones from the Giralia Range, Birdsong Sandstone and in the Molecap
Hill Quarry in Western Australia (Long 1998).
The National Heritage listed Lark Quarry in Queensland is another significant
Australian track site. Lark Quarry is remarkable for the sheer number of prints that
provide a 'snapshot' of a few minutes of activity during the Cretaceous period. Four
types of tracks of dinosaurs and thousands of prints are preserved at the site. Features
of the tracks have led to the interpretation that Lark Quarry captures a moment in
time: a group of smaller dinosaurs fleeing an approaching predator (Cook 1994). A
particular locality on the Dampier Coast, described as 'a beautiful mess', is one of
many that is comparable to the Lark Quarry site in its high-resolution capture of a few
minutes during the Cretaceous period: Dr Tony Thulborn, a vertebrate palaeontologist
who has worked on the Broome Sandstone localities for nearly two decades, interprets
this exposure as evidence of the passage of a herd of medium to large sauropods
'travelling along the coast in a corridor defined by a forested area (still preserved on
the eastward side) and open lagoons … I've seen nothing to approach it anywhere else
in the world' (Thulborn 2009; Thulborn 2010).
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