Australia: The Land Where Time Began

A biography of the Australian continent 

It was found in the Mackunda Formation, Thompson River near Muttaburra, and Allaru Mudstone, at Dundee near Hughenden, central Queensland. Also in the Griman Creek Formation, Lightning Ridge, New South Wales.

Muttaburrasaurus langdoni is one of the most complete dinosaur skeletons found in Australia. The well preserved skull from the Allaru Mudstone, Dundee, is slightly older than the type specimen and is regarded as being a bit more primitive (Molnar, 1996a). It is believed to have walked mostly quadrupedally, but probably stood on its hind legs to feed on high vegetation, more than 5 m above the ground, the overall length being about 10 m. A characteristic of Muttaburrasaurus was the nasal bulla (large bump) on the snout that is believed to have possibly connected with vocalisation.

Isolated Muttaburrasaurus bones and teeth have been found at Lightning Ridge, New South Wales, the form of the teeth being intermediate between those from Muttaburra and Atlascopco, a hyspilophodont, from Victoria, though still referrable to Muttaburrasaurus, form 2 (Molnar, 1996a).

A characteristic of Muttaburrasaurus is the jaw structure and teeth that differ from those of closely related dinosaurs. Unlike the situation in the other related dinosaurs, the crowns of the teeth have all erupted by the same amount, suggesting that all the teeth erupted together. In other dinosaurs the eruption of the teeth is more spasmodic. Food could be sheared by the jaws rather than ground. Their bite was apparently very powerful, judging by the large attachment areas of the jaw muscles. It has been suggested that this animal might have been an occasional carnivore (Bartholomai & Molnar, 1981). Camptosaurus from the Upper Jurassic of Europe and North America is believed to be the most closely related dinosaur.

It is defined as a large basal ornithopod. There is a broad, low postorbital region on the skull, on the snout the nasal bulla is prominent, the quadrate is posteriorly inclined, lateral processes on the frontal, and the maxillary crowns are all erupted to the same degree. There are about 11 low ridges on the maxillary teeth, but no central carinae. The dorsal centra is keeled, ventral pits are present on the anterior caudal centra. It has 4 metatarsals. The pelvis is deep, with a long, slender ischium (Long, 1998).

Sources & Further reading

1. Long, John A, 1998, Dinosaurs of Australia and New Zealand, University of New South Wales Press.

Links

1. The Age of Reptiles
2. Flinders Discovery Centre
3. Australian Age of  Dinosaurs
4. Australian Age of Dinosaur Online Shop

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6. New Australian dinosaur shows that Tyrannosaur' range was global