For four decades a little piece of fossilised bone sat in the dusty drawer of the British Antarctic Survey (BAS) collection in Cambridge, its true nature a mystery.

Scrutinised in 1985 by a BAS field team on James Ross Island, the bone was mislabelled as “vertebra of large reptile” in a field notebook. Only in 2024 did palaeontologists recognise its distinctive ball‑and‑socket joints as characteristic of a Titanosaur – the gigantic, plant‑eating dinosaurs that once roamed the planet.

The verest bone, now formally documented, is the first dinosaur fossil proven recovered on Antarctica. A 10‑centimetre crusted tail vertebra, paired with the work of Prof Paul Barrett from the Natural History Museum, confirms the specimen as a juvenile or smaller type of Titanosaur.

Scientists estimate the Antarctic Titanosaur measured about 7 metres (23 feet) long, giving new clues about the size range of these giants. The continental environment of the Late Cretaceous was a green, forested world, contrasting sharply with today’s icy expanse.

“This find shows that an area we now consider uninhabitable once supported a diverse ecosystem,” said Barrett. The bone adds a missing piece to the puzzle of how dinosaurs survived in the southernmost regions of Earth 82 million years ago.

Learn more in the peer‑reviewed paper published in Acta Palaeontologica Polonica.