Nearly four decades after its discovery, a fossilised vertebra unearthed by a British scientific expedition has been officially identified as the first dinosaur bone ever found in Antarctica. The specimen, a caudal vertebra from a titanosaur, offers fresh evidence about how these colossal reptiles dispersed across the southern hemisphere during the Late Cretaceous.
The fossil was collected in 1985 by Mike Thomson, a geologist with the British Antarctic Survey (BAS), during fieldwork on James Ross Island, part of the Antarctic Peninsula. At the time, Thomson was mapping rock strata to help future palaeontological research and recorded the bone as belonging to a large reptile. It was only recently that palaeontologists confirmed its true identity.
Mark Evans, curator of the BAS geological collections, noticed the specimen while reviewing the organisation's holdings a few years ago. “When I first saw this bone in our collections a few years ago, I suspected it was a dinosaur. After examining it more closely, I thought it was probably a caudal vertebra from a titanosaur. When we went back to Mike’s field notebooks, we found he already knew it belonged to a large reptile, so it is very special to be able to confirm his discovery 40 years later,” Evans said in a BAS press release.
A Titanosaur from 82 Million Years Ago
The vertebra belongs to Titanosauria, a group of sauropod dinosaurs that includes some of the largest land animals ever to have lived, typically weighing over 15 tonnes. However, the Antarctic specimen would have measured between six and seven metres in length, relatively modest by titanosaur standards.
The bone was found in the Santa Marta Formation, a marine sedimentary layer from the Late Cretaceous, approximately 82 million years old. It is the only dinosaur fossil discovered in Antarctica from this particular geological formation. Scientists believe that after the animal died, its carcass was carried out to sea, where it settled on the seabed and eventually became fossilised.
Professor Paul Barrett, a researcher at London’s Natural History Museum and co-author of the study, said the discovery provides new clues about dinosaur biogeography. “This discovery sheds more light on how dinosaurs spread across the southern continents. Until now, no titanosaurs had been found in Australia and the evidence from New Zealand is very limited. Confirming their presence in Antarctica suggests these animals continued their expansion into those regions, which were then connected,” Barrett explained.
When this dinosaur lived, Antarctica was radically different from today. According to BAS, the continent was covered in lush temperate forests and enjoyed a much warmer climate, driven by intense volcanic activity that released large amounts of carbon dioxide into the atmosphere. This ancient greenhouse world allowed dinosaurs to thrive near the South Pole.
Antarctica remains the continent with the scarcest dinosaur fossil record, largely due to the vast ice sheet that covers most of its surface. However, researchers believe many fossils remain hidden beneath the ice, and that its retreat could reveal new evidence of the continent's ancient biodiversity. The study, titled A titanosaurian sauropod dinosaur from the Late Cretaceous of Antarctica, has been published in the journal Acta Palaeontologica Polonica.
The confirmation of this fossil underscores the importance of long-term curation and re-examination of museum collections. It also highlights how European-led research continues to shape our understanding of Earth's deep past, even in the most remote regions of the planet.
