Scientists classify dinosaurs into two major groups: Saurischia (lizard-hipped) and Ornithischia (bird-hipped), based on the shape of their pelvises (hip bones). The dinosaur hip consists of three bones: ilium, ischium, and pubis. The ilium is the large bone that connects the pelvis to the backbone, while the ischium and pubis serve as attachment points for powerful leg muscles. In Saurischian dinosaurs, the ischium points backward and the pubis points downward, forming a three-pronged shape similar to that of reptiles. In contrast, Ornithischian dinosaurs have both the ischium and pubis pointing backward and paralleling each other, resembling the pelvic structure of birds.
Saurischian dinosaurs can be further divided into Sauropodomorphs and Theropods. Sauropodomorphs are plant-eaters characterised by their long necks and massive bodies, including species like Brachiosaurus and Diplodocus. Theropods, primarily meat-eaters, are known for their bipedal stance and agility, with notable examples such as Tyrannosaurus and Velociraptor. On the other hand, all Ornithischian dinosaurs are plant-eaters, including Cerapods like Triceratops and Iguanodon, as well as Thyreophorans such as Ankylosaurus and Stegosaurus.
Classifying dinosaurs is a complex task, and finding large, intact dinosaur fossils is like searching for a needle in a haystack. For instance, the dinosaur fossils found in Port Island are just fragments, making it difficult to determine their exact type. Based on current findings, experts speculate that the fossils may belong to either the Sauropod or the Ornithischian group of dinosaurs. We look forward to uncovering more details with the latest batch of rocks containing dinosaur bone fossils that have been evacuated from Port Island.
In addition to viewing Hong Kong’s first dinosaur fossil at the Hong Kong Heritage Discovery Centre, you can explore the Palaeontology Gallery at Hong Kong Science Museum. There, you can learn about the formation and discovery of fossils, interact with the life-like animatronic dinosaurs, and delve into the stories of dinosaurs and other prehistoric creatures through interactive exhibits.
