?Allosauroid

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Information
PRONOUNCED	Al-low-saw-roid
MEANING	Strange Reptile
CLASSIFICATION	Allosauroidea, Tetanurae, Theropoda
AGE	Early Cretaceous (Aptian) 115 MYA
FORMATION	Wanthaggi Formation (Strzelecki Group)
SIZE	?6 metres (19 feet) long
LOCATION	Cape Patterson, Victoria

A possible Allosauroid dinosaur is known from Australia by a single nearly complete astragalus (ankle bone) found at Cape Patterson below the Strzelecki ranges in Victoria, Australia, by Tim Flannery in 1979. This is the same area in which the first dinosaur bone from Victoria was found, a toe claw of a small theropod dinosaur found by William Ferguson in 1903, that was taken to England and described by A.S.Woodward in 1906.

The astragalus is distinctive of different theropod genera, and is the smallest bone for which Allosaurus species can be so precisely identified. It was taken to the United States and compared with 55 other North American Allosaur specimens, and found to be more robust than any of them. If this bone was from an adult then it would have belonged to an individual much smaller than most Allosaur species, around 6 metres (19 feet) long and 2 metres (6.5 feet) tall, as compared to average lengths of between 9 and 11 metres (29.5 to 36 feet) for adult Allosaurs from other parts of the world. A partial manual (hand) claw from the same area of south eastern Australia has since been found that would have measured about 15cm (6 inches) in length, indicating that there were also Allosaurus sized species living along side the smaller varieties.

Other allosaur-like material has been recovered from Western Australia. A theropod mid caudal vertebra from the Early Cretaceous was found in 1993/94, that compares closely with the caudal vertebrae of allosaurs. A theropod toe bone from the Late Cretaceous found in 1992 also shows some similarities with Allosaurus. These creatures have been estimated as having been 5 and 4 metres long respectively, assuming allosaur-like body plans.

In 1998 the astragalus was re-examined by Dan Chure, who concluded that it was probably not from an Allosaurus, although it could well be Allosauroid. This material may be properly described sometime soon, perhaps even getting its own offical name. The recently described Allosauroid from Japan, Fukuiraptor kitadaniensis, is said to have an astragalus that closely resembles the Victorian specimen. The Japanese theropod is also much smaller than an adult Allosaurus, at just over 4 metres long, and seems to be related to Sinraptor dongi from China.

This reconstruction is another based on a single bone (see Kakuru). I have based it on a generalized allosaur body plan, with the distinctive pre-orbital ("before the eyes") horns and paired nasal ridges. The head is relatively larger and the limbs somewhat more robust than in the North American Allosaurus fragilus, reflecting its "dwarf" nature.