Scelidosaurus: ready for its closeup at last

For various reasons, the research staff of the Natural History Museum in London, where the specimen is now stored, did not restudy Owen’s old dinosaur, even though the skeleton had undergone decades of preparation to clean up its bones.The rocks in which this dinosaur’s bones were fossilised, known as ‘Blue Lias’ on Dorset's Jurassic Coast, are around 193 million years old, close to the dawn of the Age of Dinosaurs, making it a potentially vital specimen to understanding how the major dinosaur groups evolved and how they relate to one another. The results of Norman’s work, published as four separate studies in the Zoological Journal of the Linnean Society of London, not only reconstruct what Scelidosaurus looked like in life, but reveal that it was an early ancestor of ankylosaurs, the armour-plated ‘tanks’ of the Late Cretaceous Period. In a study published in Nature, the researchers suggested that bird-hipped dinosaurs and lizard-hipped dinosaurs such as Tyrannosaurus evolved from a common ancestor, potentially overturning more than a century of theory about the evolutionary history of dinosaurs.Their new pattern of relationships looks like this: Another fact that emerged from their work on dinosaur relationships was that the earliest known ornithischians first appear in the Early Jurassic Period. "Scelidosaurus is just such an Early Jurassic dinosaur and therefore represents a species that appeared at, or close to, the evolutionary ‘birth’ of the Ornithischia," said Norman, who is a Fellow of Christ's College.