When I was a young dinosaur fan, Spinosaurus was one of my most favorite dinosaurs. What could be more fantastic than a giant predatory dinosaur equipped with a bizarre sail? But Spinosaurus as I knew it during the 1980s—imagine a fin-backed Allosaurus—looked significantly different from the dinosaur as we know it today. The reason for the big change is largely attributable to the discovery of a different, related dinosaur in England.
In 1986, Alan Charig and Angela Milner described a very strange, crocodile-snouted dinosaur they called Baryonyx. The Cretaceous creature turned out to be the key to identifying what is now one of the most famous dinosaur groups, the spinosaurs. Paleontologists had been finding pieces of spinosaurs for over a century, but often the teeth of these dinosaurs were confused for those of crocodiles, and the original Spinosaurus fossils were destroyed during Allied bombing of Germany in WWII. When Baryonyx was discovered, however, paleontologists began to recognize the similarities between it, older discoveries and similar dinosaurs that were soon found in South America, Africa, Asia and Australia. Some, such as Suchomimus and Spinosaurus from Africa, had sails, while others—including Baryonyx—did not, but the initial discovery formed the basis for the great spinosaur makeover. (Even before new Spinosaurus material was found, the relationship between it and other spinosaurs like Baryonyx was used to restore the predator with heavy-clawed hands and an elongated snout.) In the above video, created by London’s Natural History Museum, paleontologist Angela Milner explains how the dinosaur was discovered and why Baryonyx is so peculiar compared to other predatory dinosaurs.