Antarctica's first found dinosaur fossil confirmed nearly 40 years after discovery

A dinosaur bone discovered in Antarctica in 1985 has been confirmed as the first dinosaur fossil ever found on the continent, providing new insights into how dinosaurs spread across the southern continents millions of years ago.

Researchers at the British Antarctic Survey (BAS) identified the fossil as a vertebra from a young titanosaur, a group of long-necked herbivorous dinosaurs that included the largest land animals to have ever lived, ABC.Net writes. 

The 10-centimetre-wide bone was uncovered by geologist Dr. Mike Thomson while mapping rock layers on James Ross Island in December 1985. At the time, Thomson recorded in his field diary: "Vertebra of large reptile."

Dr. Neil Evans, a paleontologist at BAS, said the fossil's distinctive shape prompted a closer examination.

"When I first spotted this bone in our collections a few years ago, I suspected it was a dinosaur," Dr. Evans said.

He added: "Looking back at Mike's notebooks, he knew it was a large reptile so it's very special to confirm his find 40 years later."

The fossil is believed to have belonged to a juvenile titanosaur measuring about six to seven metres long. Adult titanosaurs could exceed 35 metres in length and weigh more than 15 tonnes.

The vertebra was recovered from marine rocks dating back about 82 million years, when Antarctica had a warm, forested climate rather than its present-day ice-covered landscape. Scientists believe the animal's carcass drifted into the sea after its death before being buried and fossilized.

Paul Barrett, a researcher at London's Natural History Museum, said the discovery helps explain dinosaur migration across the ancient southern landmasses.

"To date, no titanosaurs have been found in Australia, and there is only limited evidence of them in New Zealand," Professor Barrett said.

Only about a dozen dinosaur fossils have been discovered in Antarctica, making such finds exceptionally rare due to the continent's extensive ice cover.

Steven Salisbury, who was not involved in the study, described the confirmation as an important addition to the continent's limited fossil record.

"Not only has it extended our timing of recognition of dinosaurs in Antarctica, but it's added to the very sparse record that we do have," he said.

By Sabina Mammadli