Archaeothyris
| Archaeothyris Temporal range: Late Carboniferous |
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| Life restoration of Archaeothyris | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Superclass: | Tetrapoda |
| Class: | Synapsida |
| Order: | Pelycosauria |
| Family: | Ophiacodontidae |
| Genus: | Archaeothyris |
| Species: | A. florensis |
| Binomial name | |
| Archaeothyris florensis Reisz, 1972 |
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Archaeothyris was a very early mammal-like reptile, which lived in the late Carboniferous period. Dated to 306 million years ago, it is the oldest undisputed synapsid known.[1] (Protoclepsydrops is slightly older, but its status as a synapsid is unclear as the remains are more fragmentary). It was found in Nova Scotia, at the same locality as Hylonomus, and Petrolacosaurus, all of which resemble Archaeothyris.
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[edit] Systematics
Archaeothyris belonged to the family Ophiacodontidae, a group of early pelycosaurs that evolved early in the Late Carboniferous. It is thus seen as the precursor of all synapsids (which include mammals).
[edit] Appearance and lifestyle
Unlike Hylonomus and its kin, Archaeothyris was relatively large, measuring 50 centimetres (20 in) head to tail. It was also more advanced than the early sauropsids, having strong jaws that could open wider than those of the early reptiles. While its sharp teeth were all of the same shape, it did possess a pair of enlarged canines, suggesting that it was a carnivore.[2]
Archaeothyris lived in what is now Nova Scotia, about 306 million years ago in the Carboniferous Period (Pennsylvanian).[3] Nova Scotia at this time was a swamp, similar to today's Everglades in Florida. The "trees" (actually giant club mosses) were very tall, some, such as Lepidodendron, up to 50 metres (164 ft) tall. Archaeothyris and the other early amniotes dwelled on the forest ground.
[edit] See also
[edit] References
- ^ Falcon-Lang, H.J., Benton, M.J. & Stimson, M. (2007): Ecology of early reptiles inferred from Lower Pennsylvanian trackways. Journal of the Geological Society, London, 164; no. 6; pp 1113-1118. article
- ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 186. ISBN 1-84028-152-9.
- ^ Hess J.C., Lippolt H.J. (1986): 40Ar/39Ar ages of tonstein and tuff sanidines: new calibration points for the improvement of the Upper Carboniferous time scale. Chem Geol no 59: pp 143–154
- Kemp, T. S. (2005). The Origin & Evolution of Mammals. Oxford: Oxford University Press. ISBN 0198507615.
[edit] External links
- Transitional Vertebrate Fossils - includes description of important transitional genera from reptile to mammal (includes a little information about Archaeothyris)
