The Plesiosaur Project - from discovery to display

an amazing discovery | the outback today | Coober Pedy - back to the Cretaceous |
The Addyman Plesiosaur - a national treasure | The Plesiosaur Puzzle |
Plesiosaur Birthing Ground | Skin Deep - making the plesiosaur model

Cooper Pedy—back to the Cretaceous

Australia during the Cretaceous period was a completely different world.

"You wouldn't have recognised the country. It was largely inundated by an inland sea," explained palaeontologist Mr Ben Kear.

Mr Kear's job at the South Australian Museum was to clean the opalised plesiosaur, reconstruct and study it.

"The southern section and east coast of Australia would have been attached to Antarctica. Most of the central part of the country and the north was covered by a large inland sea."

"It probably wasn't deep but there seems to have been a temperature difference, with cold polar waters in the south and slightly warmer waters in the north.''

There would have been freezing bottom waters and seasonal sea-ice covering the ocean over what is now South Australia.

Photograph by Leon Mead, The Advertiser Dr. Tim Flannery inspecting the fossilised skeleton of an ichthyosaur (Platypterygius longmani) found exposed in Bulldog Shale on Moon Pain north of Coober Pedy.

On land

At this time, many small herbivorous dinosaurs roamed on the land, along with larger two-legged herbivorous ornithopods, gigantic sauropods, carnivorous theropods and mammals. Palaeontologists have also discovered evidence of other dinosaurs that lived in Australia including armoured ankylosaurs and stegosaurs, and sickle-clawed dromaeosaurs.

In water

In the rivers, lakes and oceans lived an array of crocodiles, turtles, fish, sharks, ichthyosaurs, rare labyrinthodont amphibians, and a variety of the plesiosaurs.

120 million years ago, the Eromanga Sea covered much of what we today call South Australia.

The Addyman Plesiosaur - a national treasure

The study and preparation of the opalised Addyman plesiosaur skeleton began in December 2000 after The Advertiser purchased the fossils and donated them to the Museum. For twelve months visitors to the Museum were able to watch as Ben Kear, a Museum palaeontologist cleaned the opalised bones in a specially constructed workshop in the Museum's fossil gallery. Following its preparation, Jo Bain the Museum's taxidermist, carefully mounted the Addyman plesiosaur skeleton for display in the new Origin Energy Opal Fossil Gallery.

The Addyman plesiosaur belonged to a group of long-necked plesiosaurs known as elasmosaurs.

The Addyman plesiosaur is a priceless piece of our natural heritage. It provides vital evidence of the past life of an ancient, extinct marine predator.

Ben Kear cleaning a part of the opalised plesiosaur skeleton in the Origin Energy Fossil Gallery.	Work bench in the Origin Energy Fossil Gallery with plesiosaur fossils laid out ready for display.