Dinosaur fossil discovery may be the oldest stegosaur ever found

Fossils have led researchers to a previously unknown species of armoured dinosaur that lived 168 million years ago, and it's unlike anything they've ever seen before.

The ancient fossil belongs to a stegosaur, an herbivorous dinosaur with a tiny head and bony plates marching down its back, ending in a spiked tail. The specimen also had some unique characteristics that can't be traced in other stegosaurs. It's the oldest one recovered from Asia and may belong to one of the earliest stegosaurs ever found, according to new research.

The study published Thursday in the Journal of Vertebrate Paleontology.

Stegosauria is one of a larger group of armored dinosaurs known as thyreophorans that lived during parts of the Jurassic period as well as the early Cretaceous period, between 100.5 million and 201 million years ago. Their fossils, belonging to 14 different species, have been found nearly everywhere except for Antarctica and Australia.

Researchers uncovered dinosaur fossils in 2016 at a well-known site called the Shaximiao Formation in the Chongqing municipality of China. Part of this site dates to the Middle Jurassic period, which lasted between 163.5 million and 174.1 million years ago.