Antrodemus
an-TROH-deh-mus /ænˈtroʊdəməs/
Synonym of Allosaurus
cavity body
- antron · Greek · cavity, cave
- demas · Greek · body
The name combines the Greek words for "cavity" and "body". Leidy chose it because the vertebra he described had hollow cavities in its sides. These are now known to be air-sac spaces, called pleurocoels. The name refers to the hollowed-out look of the bone.
- Named by
- Leidy
- Year named
- 1870
- Period
- Late Jurassic
- Found in
- Morrison Formation, Colorado, USA
Antrodemus (type species A. valens) was based on a single tail vertebra. It was long used as the name for the large Morrison Formation theropod now called Allosaurus, until Gilmore (1920) showed the two names covered the same animal. Antrodemus is older than Allosaurus (Marsh, 1877). Its type material is not distinctive enough to identify a genus, so Allosaurus is the name in use. Some authors treat Antrodemus valens as a nomen dubium.