Records of the Western Australian Museum 17:143-146 (1995). 
A theropod dinosaur bone from the Late Cretaceous Molecap Greensand, 
Western Australia 
John A. Long 
Department of Earth and Planetary Sciences, Western Australian Museum, Francis Street, Perth, 
Western Australia 6000 
Abstract - A proximal pedal phalanx from a theropod dinosaur is recorded 
from the Late Cretaceous Molecap Greensand, at Gingin, Western Australia. 
It is only the second record of a Late Cretaceus dinosaur from Australia, and 
the first dinosaur bone recovered from the Perth Basin. 
INTRODUCTION 
Dinosaur remains are extremely rare in Western 
Australia. Only two bones have been previously 
recorded, a sauropod caudal vertebra from the 
Middle Jurassic Colalura Sandstone exposed at 
Bringo Cutting, near Geraldton, and a possible 
theropod humerus from the Late Cretaceous (late 
Maastrichtian) Miria Formation in the Giralia 
Range, south of Exmouth Gulf (Long 1992). In July 
1992 a University of Western Australia Geology 
Department second year field excusion to the 
Molecap Quarry, at Gingin, discovered the third 
dinosaur bone from the state. The specimen, a 
small pedal phalanx, was found by student Michael 
Green and donated to the Western Australian 
Museum. The bone (WAM 92.7.1, Figure 1, 2 E-H) 
was found in situ in the Molecap Greensand at a 
height of about 2 metres above the quarry floor in 
the western face of the quarry. The age of the 
Molecap Greensand has been assessed as ranging 
from from Cenomanian to lower Turonian (Shafik 
1990) to possibly Santonian (McWhae et al. 1958). 
To date the only other vertebrate remains 
recovered from the Molecap Greensand are 
chondrichthyan and teleost teeth, three mosasaur 
paddle bones (Lundelius and Warne 1960), and 
isolated plesiosaur and ichthyosaur bones and 
teeth (McNamara et al. 1993; Long 1993). 
The only other bones of theropod dinosaurs 
described from Australia are all of Early 
Cretaceous age. An isolated theropod claw from 
Cape Patterson, southern Victoria, was described 
by Woodward (1906), and a caudal vertebra from 
Lightning Ridge was named as Walgettosuchus 
woodwardi by Von Huene (1932), although it is now 
regarded as a nomen dubium (Molnar 1991). A 
partial tibia and an isolated phalanx from 
Andamooka, South Australia, were identified as 
belonging to a new slender theropod called Kakuru 
kujani (Molnar and Pledge 1980). The Victorian 
outcrops of the Strzelecki and Otway Groups 
include an astragalus of Allosaurus sp. (Molnar et 
al. 1981), and undescribed vertebrae, jaw and limb 
bones from theropods, including 
omithomimosaurs and a possible oviraptorid (Rich 
1993; Rich et al. 1991, Rich and Vickers-Rich 1994). 
The comparison made between the Gingin 
theropod and Allosaurus fragilis shown in Figure 2 
is not to suggest that the Gingin specimen is here 
identified as Allosaurus, only to make the point that 
the specimen is a theropod with very close 
resemblances to Allosaurus. It is beyond the scope 
of this paper to compare phalangeal proportions of 
the known theropod dinosaurs with the Gingin 
specimen, only to record the specimen and make 
some general observations and comparisons. 
DESCRIPTION OF THE SPECIMEN 
The Gingin phalanx (WAM 92.7.1, Figure 1) is 
40.8 mm in length, 25.7 mm proximal depth, 26.2 
mm proximal width, 20.8 mm distal depth and 24.4 
mm in distal width. The asymmetry of the distal 
articular condyles indicates it is from the left pes. 
The ventral surface shows the presence of a 
thickened platform of rugose bone close to the 
posteromedial corner (the flexor tubercle, shown 
arrowed in Figure 2 B, F) and the posterolateral 
corner has a slightly concave area of bone. The 
proximal face is relatively flat with only weak 
development of the articular ridges which received 
the distal face of the fourth metatarsal. In lateral 
view the ventral margin of the shaft of the bone is 
strongly concave, and the articular condyles of the 
distal end are well rounded and stand out 
prominantly from the neck of the shaft. The distal 
end of the phalange has well-defined, quite large 
collateral ligament fossae on each side. 
The bone is well preserved and its characteristic 
proportions indicate that it is a pedal phalanx of a 
