Dr Mark Evans, the collections manager at BAS, recently spotted the fossil amongst thousands of specimens brought back from expeditions to Antarctica over the decades.
“It’s only when you start thinking ‘what’s in this drawer’, that sometimes you come across something and you think, ‘Ah, this looks interesting’,” he said.
The specimen was originally collected on James Ross Island and its discovery was recorded in a field notebook kept by geologist Dr Mike Thomson.
Alongside a tiny, neat sketch of the fossil dated 9 December 1985 he has written “vertebra of large reptile”, noting it was about 10cm wide.
Evans says the team that found it probably thought the fossil belonged to a marine reptile.
But as soon as he saw it, Evans realised the vertebra looked very dinosaur-like. And the date of its discovery meant it would have been the first dinosaur fossil found on the continent.