They were the biggest animals ever to walk the Earth – now a new fossil suggests the largest sauropod dinosaurs were even bigger than we thought.

Sauropods were enormous plant-eating beasts with long necks and tails. The biggest are aptly named titanosaurs, and could reach 30 metres long and weigh 80 tonnes.

But some titanosaurs may have been even bigger than that, says Rodolfo García at the National University of Río Negro in Argentina. He has found a 7.5-centimetre-long titanosaur tooth at Salitral de Santa Rosa in Río Negro – that makes it 32 per cent longer than the previous record holder.

Did it belong to a titanosaur even bigger than any found so far? García says it is possible: the tooth probably came from an enormous skull, he says, which suggests a monumental body.


Philip Mannion of Imperial College London points out that we do not yet have good fossil skulls of the largest titanosaurs, so the tooth might simply belong to one of them. We’ll need to find more of the dinosaur from which the tooth came to convince him that it was an even bigger beast.

If more evidence was found to suggest its existence, the next task would be to name it. Palaeontologists would need to go one better than Ultrasaurus, Supersaurus and Megalosaurus but Colossasaurus is still up for grabs.

Journal reference: Cretaceous Research, doi.org/j2w

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