Theropoda Conservation status: Fossil
T. Rex skull Picture taken at Field Museum of Natural History, Chicago
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Archosauria Superorder: Dinosauria Order: Saurischia Suborder: Theropoda
Families
See text

Theropods ("beast foot") are a group of bipedal, primarily carnivorous dinosaurs, belonging to the saurischian ("lizard-hip") family. They flourished from the Late Triassic (~220 million years ago) until the close of the Cretaceous(65 million years ago), yet are today represented by the 8600 living species of birds.

Some kinds of theropods are: tyrannosaurs, including the famous Tyrannosaurus rex, the dromaeosaurs, including Velociraptor and Deinonychus, the herbivorous ornithomimids and oviraptorosaurs, and the birds. A number of features link them to birds, including a three-toed foot, a wishbone, air-filled bones, and (in some cases) feathers and brooding of the eggs.

Theropod classification is an area of research in a state of flux, but broadly speaking, there are three main groups recoginised. The Ceratosauria are a diverse group which includes animals with odd cranial morhpology. Examples include the twin-crested Dilophosaurus of Jurassic Park fame and Ceratosaurus which had bony nodules on its nose and over each eye. The other two groups are more closely related and are referred to as the Tetanurae. This includes many of the most famous Theropods and is subdivided into the Spinosauroidea and the Avetheropoda. The latter group is again divided into the Carnosauria (which includes Allosaurus) and the Coelurosauria, which includes animals as well known and diverse as Velociraptor and Tyrannosaurus rex. It is from this last sub-group that birds are thought to be descended.

Known theropod species include:

• Allosaurus
• Deinonychus
• Tyrannosaurus rex
• Velociraptor
• Ornithomimus

T.rex foot, picture taken at Field Museum of Natural History