Английская Википедия:Archaeothyris

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Шаблон:Short description Шаблон:Automatic taxobox

Archaeothyris is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, Archaeothyris, along with a more poorly known synapsid called Echinerpeton, are the oldest undisputed synapsids known.[1] The name means ancient window (Greek), and refers to the opening in the skull, the temporal fenestra, which indicates this is an early synapsid. Protoclepsydrops also from Nova Scotia is slightly older but is known by very fragmentary materials.[2]

Файл:Archaeothyris NT small.jpg
Archaeothyris florensis

Description

Файл:Archaeothyris.svg
Skull reconstruction of A. florensis

Archaeothyris was 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 size & shape, it did possess a pair of enlarged canines, suggesting that it was a carnivore.[3]

Archaeothyris' legs were articulated laterally at its pelvis and shoulders, which gave it a sprawling stance.Шаблон:Citation needed The first toe is smaller than the second.Шаблон:Citation needed

Classification

Archaeothyris belonged to the family Ophiacodontidae, a group of early pelycosaurs that evolved early in the Late Carboniferous. It was one of the earliest and most basal synapsids (the group which includes mammals).

Below is a cladogram modified from the analysis of Benson (2012):[4]

Шаблон:Clade

Discovery and paleoecology

Fossils of Archaeothyris were first described in 1972 from the Joggins fossil cliffs, the same locality in which the early reptiles Hylonomus and Petrolacosaurus (both of which resemble Archaeothyris) were found.

Archaeothyris lived in what is now Nova Scotia, about 306 million years ago in the Carboniferous Period (Pennsylvanian).[5] 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 Шаблон:Convert tall. Archaeothyris and the other early amniotes lived in the moist vegetation on the forest ground, together with the more terrestrially adapted labyrinthodont amphibians.

See also

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References

Шаблон:Reflist

Further reading

External links

Шаблон:Basal synapsids Шаблон:Taxonbar

  1. 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
  2. Шаблон:Cite web
  3. Шаблон:Cite book
  4. Шаблон:Cite journal
  5. 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