An artist's impression of two glyptodonts, giant extinct cousins of modern armadillos

Tank-like armour-plated beasts that roamed South America thousands of years ago were exactly what they looked like - giant armadillos, research has confirmed.

Glyptodonts included one species, Doedicurus, which was the size of a VW Beetle car, weighed around a tonne, and was armed with fearsome spiked tail resembling a medieval mace.

They have been dubbed "giant armadillos", but only now have scientists established that they really were ancient cousins of the creatures.

Experts found the connection after piecing together DNA extracted from fragments of glyptodont protective shell and reconstructing the animals' family tree.

Unlike modern armadillos, glyptodonts did not possess flexible bands in their armour that would have allowed them to curl their bodies up.

Dr Frederic Delsuc, a member of the international team from the CNRS research institute in France, said: "Glyptodonts should probably be considered a sub-family of gigantic armadillos.

"We speculate that the peculiar structure of their unarticulated carapace might have evolved as a response to the functional constraint imposed by the size increase they experienced over time."

Glyptodonts are thought to have evolved from an extinct armadillo lineage that emerged around 35 million years ago.

They lived alongside early modern humans, who may have hunted them, and vanished at the end of the last ice age about 10,000 years ago.

The new findings, published in the journal Current Biology, highlight the animals' spectacular growth in size to become a formidable member of the ice age megafauna.

The last common ancestor of glyptodonts and living armadillos is thought to have weighed in at a mere six kilograms (13lbs).

PA Media