"Elliot" the Sauropod

Elliot

Information
CLASSIFICATION
    Sauropodomorpha incertae sedis (titanosauriform?)
AGE
    Earliest Late Cretaceous (Aptian/Cenomanian) 95-97 MYA
FORMATION
    Winton Formation
SIZE
    16-21 metres (52-69 feet) long,
    3.5-4 metres at the hip, 22-28 tonnes
LOCATION

See Elliot's World for a description of the type of environment that "Elliot" lived in.

The remains of a sauropod were discovered in 1999 on a remote sheep station near Winton, Queensland. A farmer collected a half metre length of the right femur, several partial tail vertebrae, rib fragments, part of a metacarpal or metatarsal (either a wrist or ankle bone), and lots of smaller fragments. These first specimens were collected from a 250 by 50 metre area.

The animal was dubbed "Elliot" after the surname of the sheep station owners. With the femur estimated at between 1.5 and 1.7 metres in length (5 to 5.5 feet), it was for a while the largest dinosaur discovered in Australia (now surpassed by 'Cooper' and 'George'). Estimates suggest it may have been 16 to 21 metres in length - longer than the known Austrosaurus specimens, and potentially bigger than Rhoetosaurus at about 18 metres.

Preliminary reports called it either a "brachiosaurid" or a "titanosaurid" (brachiosaurs are considered basal titanosauriforms). Elliot's remains were found in a layer of sediments known as the Winton Formation, which dates to between 97 and 95 million years ago. This is the same formation where the fragmentary remains of five Austrosaurus sp were found in 1959, near the town of Maxwelton. The original specimen of Austrosaurus, A.mckillopi, is from the Allaru Mudstone Formation that dates to around 98-99 MYA, making it slightly older than Elliot or the other five individuals known. Elliot's vertebrae are similar to those known for Austrosaurus sp, but there are slight differences in the shape of the femur. This new sauropod may be a third species of Austrosaurus, or a closely related animal. It is currently thought that Austrosaurus may be related to the titanosaurs, however these sauropods may turn out to be a uniquely Australian group not closely related to sauropods from other parts of the world.

In early September 2001 volunteers and staff from the Queensland Museum Palaeontology and Geology lab began excavating the site. The team included Dr Steven Salisbury, "Young Australian of the Year" Scott Hocknull and Alex Cook. The site was pegged out with a grid that covered all of the visible bone fragments on the surface. The area which encompasses the surface fragments is about seven times the size of the average playing field. making it one of the biggest ever dinosaur excavations in Australia, and one of the largest in the world for a single animal. The 2001 excavation mapped out a 350 by 110 metre grid, divided into 10 by 10 metre quadrats. Finds were mapped into a GIS (Geographic Information System) to allow the site to be reconstructed in a computer at a later date. From the digital map, it will be possible to isolate the areas with the highest concentrations of bone fragments, to begin digging below the surface in earnest. At first only small fragments were found scattered about the surface, but on the final day of the expedition the well preserved head of Elliot's right femur was found while excavating a 5 by 5 metre test pit with a tractor. The femoral head alone was so large that the tractor lurched noticably when it hit it. The rest of the femur, complimenting the piece found in 1999, was found in the same place, around 1.5 metres below the surface. It was badly fragmented, but it appears that the right femur is now complete. More tail vertebrae were also recovered during this excavation.

A second excavation was conducted during July 2002, during which another 20 complete bones and around 400 fragments were discovered, mostly from the tail region. Parts of a front foot, radius (a bone in the forearm), ischium (part of the pelvis) and hind foot were also found. With 80 people working on the site, around 400 tonnes (440 tons) of rock and soil were moved to extract the fossils.

In 2003, the scattered remains of small theropods were recovered from the site, along with parts of a second sauropod (dubbed 'Mary').

Only a small portion of the Elliot site has been excavated so far, and it may turn out to be Australia's most complete dinosaur. The excavators are hoping for a near-complete skeleton. Excavations were planned to continue until 2004.

For more information see the Queensland Museum site at www.qmuseum.qld.gov.au/features/dinosaurs/elliot.

Australian Geographic magazine, Issue 65, December 2001


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