The new species, Bashanosaurus primitivus, dates to the Middle Jurassic and could be a close relative of the ancestor of all stegosaurus that came after. All the stegosaurus found have been from Asia, with bashanosaurus being found in China.

With the description of bashanosaurus, it’s believed that they may have emerged in what was then the supercontinent of Laurasia over 165 million years ago. It’s believed that the dinosaur moved to large areas in the world, beginning the evolution of many other species including the stegosaurus.

Bashanosaurus makes itself known as the true oldest stegosaur, beating Adratiklit boulahfa, which was discovered in Morocco in 2019. 

Dr Susannah Maidment, a Principal Researcher at the Museum, was involved in the description of both these species. She stated, “The discovery of this stegosaur adds to an increasing body of evidence that the group evolved in the early Middle Jurassic, or perhaps even in the Early Jurassic, and as such represent some of the earliest known bird-hipped dinosaurs. China seems to have been a hotspot for stegosaur diversity, with numerous species now known from the Middle Jurassic right the way through until the end of the Early Cretaceous Period.”

Ethan Lebel gave his thoughts, stating that “The dinosaur is super cool! I didn’t really think that dinosaurs could get any older.”