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The 'pelycosaurs' (from Greek ''pelyx'' meaning 'bowl' and ''sauros'' meaning 'lizard') were primitive Late Paleozoic synapsid amniotes. Some species were quite large and could grow up to 3 meters or more, although most species were much smaller. They appeared during the Late Carboniferous and reached their acme in the early part of the Permian Period, remaining the dominant land animals for many millions of years. A few continued into the late Permian.
At least two pelycosaur clades independently evolved a tall sail, consisting of elongated vertebral spines: the edaphosaurids and the sphenacodontids. In life, this would have been covered by skin, and possibly functioned as a thermoregulatory device or for mating display. Pelycosaur fossils have been found mainly in Europe and North America, although some small, late-surviving forms are known from Russia and South Africa.
Well-known pelycosaurs include the genera ''Dimetrodon'', ''Sphenacodon'', ''Edaphosaurus'', and ''Ophiacodon''.
In 1940 the group was reviewed in detail and every species known at the time described (and many illustrated) in an important monograph by Alfred Sherwood Romer and Llewellyn Price.
Pelycosauria is a paraphyletic taxon because it excludes the therapsids. For that reason the term is not used in some modern books. Eupelycosauria is used to designate the clade that includes most Pelycosaurs along with the Therapsida and the Mammals. In contrast to "Pelycosaurs", this is monophyletic group. Caseasauria refers to a pelycosaur side-branch or clade that did not leave any descendants.
The pelycosaurs appear to have been a group of synapsids that had direct ancestral links with the mammalia, having differentiated teeth and a developing hard palate.

Contents

Taxonomy and Phylogeny

See also

References

External links

Taxonomy and Phylogeny

★ 'Class Synapsida'

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★ 'ORDER PELYCOSAURIA'
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★ 'Suborder Caseasauria'

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★ Family Eothyrididae

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★ ''Eothyris''

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★ ''Oedaleops''

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★ Family Caseidae

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★ ''Angelosaurus''

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★ ''Casea''

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★ ''Caseopsis''

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★ ''Cotylorhynchus''

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★ ''Ennatosaurus''

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★ ''Knoxosaurus''

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★ ''Caseoides''

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★ 'Suborder Eupelycosauria'

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★ Family Varanopseidae

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★ ''Varanosaurus''

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★ ''Archaeovenator''

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★ ''Pyozia''

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★ ''Mycterosaurus''

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★ ''Mesenosaurus''

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★ ''Elliotsmithia''

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★ ''Ruthiromia''

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★ ''Aerosaurus''

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★ ''Varanodon''

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★ ''Varanops''

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★ Family Ophiacodontidae

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★ ''Archaeothyris''

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★ ''Baldwinonus''

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★ ''Clepsydrops''

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★ ''Limnostygis''

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★ ''Ophiacodon''

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★ ''Stereophallodon''

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★ ''Stereorhachis''

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★ Family Edaphosauridae

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★ ''Edaphosaurus''

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★ ''Ianthasaurus''

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★ ''Glaucosaurus''

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★ Family Lupeosauridae

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★ ''Lupeosaurus''

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★ Sphenacodontia

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★ ?''Watongia''

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★ ''Haptodus''

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★ ''Palaeohatteria''

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★ ''Pantelosaurus''

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★ ''Cutleria''

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★ Sphenacodontoidea

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★ Family Sphenacodontidae

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★ ''Ctenorhachis''

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★ ''Steppesaurus''

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★ ''Bathygnathus''

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★ ''Ctenospondylus''

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★ ''Dimetrodon''

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★ ''Neosaurus''

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★ ''Secodontosaurus''

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★ ''Sphenacodon''

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★ 'ORDER THERAPSIDA
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See also

★ Mammal-like reptiles

References

★ Reisz, R. R., 1986, ''Handbuch der Paläoherpetologie – Encyclopedia of Paleoherpetology, Part 17A Pelycosauria'' Verlag Dr. Friedrich Pfeil, ISBN 3-89937-032-5

★ Romer, AS & Price L.I (1940), Review of the Pelycosauria. ''Geol. Soc. Amer. Spec. Papers'' 28: 1-538.

External links

★ Introduction to the Pelycosaurs - at UCMP

★ Synapsida - Pelycosauria - at Palaeos