Discovery of small armoured dinosaur in Argentina is first of its kind

Palaeontologists have announced the discovery of a previously unknown small armoured dinosaur in southern Argentina, a creature that probably walked upright on its back legs roaming a then-steamy landscape about 100m years ago.

The Cretaceous period dinosaur, named Jakapil kaniukura, would have been well-protected with rows of bony disc-shaped armour along its neck and back and down to its tail, they said. It measured about 5ft (1.5 meters) long and weighed only 9-15lb (4-7kg), similar to an average house cat.

Its fossilized remains were dug up over the past decade near a dam in Patagonia in Río Negro province’s La Buitrera palaeontological zone. The scientists described jakapil in a study published on Thursday in the journal Scientific Reports.

The scientists said jakapil marked a first-of-its-kind discovery of an armoured dinosaur from the Cretaceous in South America. It is part of the thyreophoran dinosaur group that includes the likes of stegosaurus, known for its bony back plates and spiky tail, and tank-like ankylosaurus, covered in armour and wielding a club-like tail.

Lead palaeontologist Sebastián Apesteguía and his colleagues found a partial skeleton of jakapil along with 15 tooth fragments featuring a leaf-like shape, similar to iguana teeth.

Jakapil resembles a primitive form of thyreophoran that lived much earlier, making it a surprise that it dated from the Cretaceous. Apesteguía said never before had such a thyreophoran been dug up anywhere in the southern hemisphere.