Muttaburrasaurus Click to enlarge image
Illustration of Muttaburrasaurus. Image: Dr Anne Musser
© Australian Museum

Fast Facts

  • Classification
    Species
    langdoni
    Genus
    Muttaburrasaurus
    Suborder
    Cerapoda
    Infraorder
    Ornithopoda
    Order
    Ornithischia
    Superorder
    Dinosauria
    Subdivision
    Avemetatarsalia
    Division
    Archosauria
    Infraclass
    Archosauromorpha
    Subclass
    Diapsida
    Class
    Sauropsida
    Series
    Amniota
    Super Class
    Tetrapoda
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    7 m long
  • View Fossil Record
    Fossil Record
    Cretaceous Period
    (141 million years ago - 65 million years ago)

Introduction

Muttaburrasaurus was a large, plant-eating ornithopod from the Early Cretaceous of eastern Australia. It is one of the most complete dinosaurs from Australia - only Minmiis more complete - and the first to be cast and mounted for display. Muttaburrasaurushad an unusual skull with a long, rounded snout that had a hollow internal chamber, perhaps to increase the volume of its calls or enhance its sense of smell.

Identification

Muttaburrasaurus was a large ornithopod that had an unusual, rounded bony snout with a hollow internal chamber. This may have enhanced the volume of its calls or its sense of smell.

Muttaburrasaurus had many other features seen in other basal ornithopods, including reduced forelimbs and a long, stiffened tail. Based on the length and strength of its limbs, Muttaburrasaurus may have been able to move on either its two back legs or on all four legs.

Habitat

Muttaburrasaurus would have lived in araucarian conifer forests near the edge of the inland Eromanga Sea that covered vast areas of central Australia 110 million years ago. The forest understorey would have included ferns and cycads, possibly part of the diet of Muttaburrasaurus. In the more southerly part of its range (Lightning Ridge), there would have been extremes of daylight during winter and summer months, although the climate was much milder then than it is today.

Distribution

Muttaburrasaurus is Australia's most widely distributed dinosaur, known from both Queensland and New South Wales. It was discovered near the town of Muttaburra in central Queensland (on the Thomson River in the marine Mackunda Formation). Other Queensland Muttaburrasaurus material comes from Dunluce Station near Hughenden in the north-central part of the state, and from Iona Station southeast of Hughenden. A possible second species of Muttaburrasaurus has been found at Lightning Ridge in north central New South Wales.

Feeding and diet

There is no direct fossil evidence for the diet of Muttaburrasaurus although it probably included ferns, cycads, club-mosses and podocarps - all known from the area - in its diet. Although it was mainly (if not fully) a plant-eater, some scientists have suggested that, based on the shape of its teeth, Muttaburrasaurus may have occasionally eaten some meat.

Fossils description

The holotype of Muttaburrasaurus is a partial skeleton found near the town of Muttaburra in central Queensland. This skeleton (about 60% complete) was most likely a carcass that had floated out to sea from nearby land before sinking and fossilising. Other Queensland Muttaburrasaurus material includes a second skull from Hughenden in the north-central part of the state (older and more primitive than the Muttaburra skull) and isolated teeth and bones collected from Iona Station southeast of Hughenden. Opalised teeth and a scapula (shoulder blade) of what may be a different species of Muttaburrasaurus have been found at Lightning Ridge in north central New South Wales (held by the Australian Museum). There are therefore at least two (and possibly three) species of Muttaburrasaurus although this has not been confirmed by formal description.

Evolutionary relationships

The evolutionary relaltionships of Muttaburrasaurus are uncertain. It may be closely related to the Tenontosauridae , a group of basal ornithopods with few specializations that evolved from an early ornithopod group in the latter part of the Jurassic. Tenontosauridae includes Tenontosaurus, a large ornithopod similar to Muttaburrasaurus in shape and form (except for the distinctive snout of Muttaburrasaurus). It also resembles the small Australian ornithopod Atlascopcosaurus from Victoria, whose relationships are currently under study.

References

  • Bartholomai, A. and Molnar, R. E., 1981. Muttaburrasaurus, a new iguanodontid (Ornithischia: Ornithopoda) dinosaur from the Lower Cretaceous of Queensland. Memoirs of the Queensland Museum 20: 319-349.
  • Molnar, R. E., 1996. Observations on the Australian ornithopod dinosaur, Muttaburrasaurus. Memoirs of the Queensland Museum 39, 639-652.

Further reading

  • Long, J. A. et al. 2002. Dinosaurs of Australia and New Zealand and Other Animals of the Mesozoic Era. New South Wales University Press, Sydney.
  • Cannon, L., 2006. The Muttaburra Lizard. Australian Age of Dinosaurs 4, 16-31.