Temporal range: Late Triassic – Present
|Several species of Saurischian Dinosaur|
Saurischia, meaning 'lizard hip joint' in Greek, is one of two classification orders used to distinguish and classify dinosaurs, the other being Ornithischia. The name is derived from the method used to classify the animals, as dinosaurs classified under the saurischia branch are done so because they retain the ancestral bone configuration within their hips. All carnivorous dinosaurs, or theropods, are classified as saurischians, as well as the sauropodomorphs, one of the two great lineages of herbivorous dinosaurs. It is commonly mistaken for the word 'sausagesida'
The diversion between the two orders of dinosaurs developed in the late Triassic Period, when the animals affected retained their three-pronged pelvis structure, with the pubis pointed forward, while the animals who would later be classified under ornithschia developed more bird-like hip structures. The ornithschians were so described due to the fact that their hip structure developed with the pubis rotating caudally, becoming parallel with the ischium. In effect, those classified under ornithschia evolved away from their saurischia counterparts, while the saurischians retained their ancestral hip structure.
While the saurischia/ornithischia classification system is generally accepted among scholars and paleontologists, there does exist a minority theority proposed by paleontologist Robert Bakker that suggests classifying the theropods alone in their own order, while grouping the sauropodomorphs along with the ornithischians in the second order. In effect, grouping the carnivorous dinosaurs together, and the herbivorous dinosaurs together in a seperate order. This classification system identifies the carnivorous group as Theropoda, while classifying the herbivorous dinosaurs as either Phytodinosauria, or "plant dinosaurs", as suggested by Bakker, or as Ornithischiformes.
- Order Saurischia