A fossil kept for four decades in a British Antarctic Survey collection has been identified as the first dinosaur bone ever collected in Antarctica. Palaeontologists concluded that the specimen, recovered from James Ross Island in 1985, is a tail vertebra from a titanosaur.
The original field team did not know the fossil’s identity. Geologist Mike Thomson recorded the find in a notebook on December 9, 1985, adding a small drawing and describing it as the vertebra of a large reptile about 10 centimetres wide. The discoverers may have believed it came from a marine reptile, and it subsequently remained among thousands of geological specimens in Cambridge.
Mark Evans, collections manager at the British Antarctic Survey, noticed the fossil while reviewing the holdings. Its appearance suggested a dinosaur vertebra, and the collection date meant that a confirmed identification could predate Antarctica’s other known dinosaur finds. Evans asked Paul Barrett of the Natural History Museum to assess it.
Barrett identified a distinctive combination of structures: a hollow at one end and a rounded projection at the other. Such vertebrae connect as ball-and-socket joints along the spine. He concluded that the features were unique to titanosaurs, a widespread group of four-legged, long-necked herbivorous dinosaurs with balancing tails.
More than 100 titanosaur species have been identified worldwide. The largest members exceeded 35 metres in length and weighed about 60 tonnes, but the Antarctic animal represented by this bone was estimated at roughly seven metres long. Researchers could not determine from the single specimen whether it was a juvenile or an unusually small adult.
The animal lived about 82 million years ago during the Late Cretaceous Period. Antarctica then had a forested environment capable of supporting plant-eating dinosaurs, in sharp contrast with the continent’s modern ice-covered landscape. The vertebra adds evidence about that ancient ecosystem in a region where dinosaur fossils remain scarce.
Antarctic palaeontology presents unusual obstacles. Ice hides much of the relevant rock, while the continent’s remoteness makes fieldwork difficult. Those constraints increase the value of existing collections: material gathered on earlier expeditions can acquire new scientific importance when specialists revisit uncertain specimens with different expertise.
The identification also changes the historical record. Dinosaur fossils were found elsewhere in Antarctica after 1985, but the date attached to Thomson’s documented specimen establishes it as the earliest known dinosaur bone collected on the continent. A paper describing the finding was published in Acta Palaeontologica Polonica.
What appeared to be an unremarkable object in a drawer now connects the history of Antarctic exploration with a clearer picture of life near the bottom of the world roughly 80 million years ago.
