Queensland Museum Network paleontologists have excavated Australia’s first head and associated body of a 100-million-year-old long-necked marine reptile. Paleontologists are calling the fossil found the Rosetta Stone of marine reptile palaeontology. This new fossil find could hold the key to unlocking the mystery around Australian plesiosaurs. The rare fossil was discovered by a Western Queensland station owner Cassandra, who, alongside two friends, Sally and Cynthia, formed a fossil- hunting trio called the ‘Rock Chicks’.Along with the new skeleton, the discoverers found several other plesiosaurs and ichthyosaurs on the field trip. They will be transported to Townsville for preparation and further research. 

Each year, the Rock Chicks meet to search for fossils on the property. During this time have walked hundreds of kilometers on their quest to uncover fossils. They include a plesiosaur each a kronosaurus, an ichthyosaur and several fish and turtles. 

Cassandra said they are looking forward to their 2023 hunt. They have a motto of “let’s keep the paleos busy”. 

“There are so many people who have helped get these amazing fossils to Queensland Museum including our friends, Tom and Sharon who helped us start digging two of the plesiosaurs,” Cassandra said. 

Plesiosaurs in Cretaceous Australia

The team of museum paleontologists recently traveled to the remote site to collect the fossil of the elasmosaur, which is a plesiosaur that co-existed with dinosaurs. 

Queensland Museum Network Senior Scientist and Curator of Palaeontology, Dr Espen Knutsen, who led the field trip said this would be the first known head and body of an Australian elasmosaur to be held in a museum collection. 

“We were extremely excited when we saw this fossil – it is like the Rosetta Stone of marine paleontology as it may hold the key to unraveling the diversity and evolution of long-necked plesiosaurs in Cretaceous Australia,” Dr. Knutsen said. 

“We have never found a body and a head together and this could hold the key to future research in this field. 

“Because these plesiosaurs were two-thirds neck, often the head would be separated from the body after death, which makes it very hard to find a fossil preserving both together, so we are using CT scanning to give us an insight into these magnificent animals.” 


Helping lift the veil on their prehistoric lives

During the early Cretaceous period (between 145.5 and 65.5 mya), much of Queensland was covered in a vast, shallow sea (the Eromanga Sea) and fossil remains of the ocean’s inhabitants, including marine reptiles, such as plesiosaurs and ichthyosaurs are commonly found across the state. 

To help answer questions about their origins and ecologies, these new specimens along with modern analytical methodologies will help lift the veil on their prehistoric lives. 

CT scans and 3D models

Queensland Museum Network CEO Dr Jim Thompson said this find would assist Dr. Knutsen and his team to paint a comprehensive picture of Queensland’s Cretaceous marine reptiles. 

“We now hold the only head and body of an Australian elasmosaur in the world, and this significant find will contribute greatly to vital research into Queensland’s Cretaceous past,” Dr. Thompson said. 

“Queensland Museum Network holds one of Australia’s most complete plesiosaur specimens, nicknamed ‘Dave the Plesiosaur’, which was discovered in 1999, however despite having 80 per cent of its bones, it was missing a head, fins and tail tips. 

“Through Project DIG, CT scans and 3D models will help us interpret data and potentially describe a new species.”