Mounted skeleton of Dimetrodon mileri, Harvard Museum of Natural History
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
Chordata
Superclass:
Tetrapoda
Clade:
Reptiliomorpha
Clade:
Amniota
Clade:
Synapsida
Informal group:
†Pelycosauria Cope, 1878
Groups included
†Caseidae
†Eothyrididae
†Varanopidae
†Ophiacodontidae
†Edaphosauridae
†Palaeohatteriidae
†Sphenacodontidae
Cladistically included but traditionally excluded taxa
Therapsida
Pelycosaur (/ˈpɛlɪkəˌsɔːr/PEL-ih-kə-sor)[1] is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants. Previously, the term mammal-like reptile had been used,[2] and pelycosaur was considered an order, but this is now thought to be incorrect, and seen as outdated.
Because it excludes the advanced synapsid group Therapsida, the term is paraphyletic and contrary to modern formal naming practice.[3][4] Thus the name pelycosaurs, similar to the term mammal-like reptiles, had fallen out of favor among scientists by the 21st century, and is only used informally, if at all, in the modern scientific literature.[5][6] The terms stem mammals, protomammals, and basal or primitive synapsids are instead used where needed.
^Cope, E. D. (1878). "Descriptions of extinct Batrachia and Reptilia from the Permian formation of Texas". Proceedings of the American Philosophical Society. 17 (101): 505–530. JSTOR 982652.
^Carroll, R.L. 1988. Vertebrate Paleontology and Evolution. WH Freeman and Company, New York ISBN 0-7167-1822-7
^Hennig, Willi (1981). Insect phylogeny. Chichester [England]: J. Wiley. pp. xi + 514. ISBN 0471278483.
^D. W. Dilkes, R. R. Reisz (1996). "First Record of a Basal Synapsid ('Mammal-Like Reptile') in Gondwana". Proceedings of the Royal Society B. 263 (1374): 1165–1170. doi:10.1098/rspb.1996.0170.
^Botha-Brink, J.; Modesto, S.P. (2007). "A mixed-age classed 'pelycosaur' aggregation from South Africa: Earliest evidence of parental care in amniotes?". Proceedings of the Royal Society B. 274 (1627): 2829–2834. doi:10.1098/rspb.2007.0803. PMC 2288685. PMID 17848370.
^Cite error: The named reference La10 was invoked but never defined (see the help page).
Pelycosaur (/ˈpɛlɪkəˌsɔːr/ PEL-ih-kə-sor) is an older term for basal or primitive Late Paleozoic synapsids, excluding the therapsids and their descendants...
This list of pelycosaurs is an attempt to create a comprehensive listing of all genera that have ever been included in the synapsida excluding therapsida...
systematics, and non-therapsid synapsids were also referred to as pelycosaurs, or pelycosaur-grade synapsids. These paraphyletic terms have now fallen out...
glaciation. Hot and dry climate. A possible drop in oxygen levels. Synapsids (pelycosaurs and therapsids) become widespread and dominant, while parareptiles and...
evolved from "pelycosaurs", specifically within the Sphenacodontia, more than 279.5 million years ago. They replaced the "pelycosaurs" as the dominant...
(Cisuralian) saw a major faunal turnover, with most lineages of primitive "pelycosaur" synapsids becoming extinct, being replaced by more advanced therapsids...
constitutes the larger Amniota clade. Early synapsids are referred to as "pelycosaurs". The more advanced therapsids became dominant during the Middle Permian...
diversified into a number of groups, including several families of synapsid pelycosaurs, protorothyridids, captorhinids, saurians and araeoscelids. The amphibian-like...
from a "pelycosaur" ancestor (a poorly defined group including all synapsids which are not therapsids). The therapsid takeover from pelycosaurs took place...
(reptiles, including dinosaurs and therefore birds) and synapsids (extinct pelycosaurs, therapsids and all extant mammals). Some tetrapods such as snakes, legless...
birds) and synapsids (including mammals and extinct ancestors like "pelycosaurs" and therapsids). They are distinguished from the other living tetrapod...
Early Permian terrestrial faunas were dominated by pelycosaurs, diadectids, and amphibians, The pelycosaurs appeared during the Late Carboniferous, and reached...
evidence for soft tissues. Skin impression of the belly and lower tail of a pelycosaur, possibly Haptodus shows the basal synapsid stock bore transverse rows...
Comparison of cheek teeth in various taxa: 1, a single-cusped pelycosaur; 2, Dromatherium (a Triassic cynodont); 3, Microconodon (a Triassic eucynodont);...
body temperature of the animal, in a similar way to the sails of the pelycosaurs Dimetrodon and Edaphosaurus (and modern elephant and rabbit ears). The...
originally considered a suborder of pelycosaurs or "mammal like reptiles", but it was redefined in 1997, and the term pelycosaur itself has fallen into disfavor...
temnospondyl amphibians and pelycosaurs (e.g. Dimetrodon) diversify in species. 275 Ma Therapsid synapsids separate from pelycosaur synapsids. 265 Ma Gorgonopsians...
groups, synapsids and sauropsids, date from around 313 Ma. The synapsid pelycosaurs and their descendants the therapsids are the most common land vertebrates...
Assemblage Zone is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. No known varanopids developed a sail like Dimetrodon...
and chelonia (turtles and relatives) Synapsida – one low fenestra – pelycosaurs and therapsids (the 'mammal-like reptiles') Euryapsida – one high fenestra...
37 (13): 385–401. Sternberg, C.W. (1942). "The skeleton of an immature pelycosaur, Dimetrodon cf. grandis, from the Permian of Texas". Journal of Paleontology...
many respects, the pelycosaurs are intermediate between the reptiles and mammals" http://www.ucmp.berkeley.edu/synapsids/pelycosaurs.html Berkeley University...
at the base than higher up, and were unlike the thin rods seen in the pelycosaur finbacks Edaphosaurus and Dimetrodon, contrasting also with the thicker...
borealis, formerly known as Bathygnathus borealis, is an extinct species of pelycosaur-grade synapsid that lived about 270 million years ago (Ma) in the Early...
caseid pelycosaurs and, before them, the diadectid reptiliomorphs. They are much larger than the diadectids, more similar to the giant caseid pelycosaur Cotylorhynchus...
publication of two of the best-known fossil taxa described by Cope: the pelycosaur Edaphosaurus in 1882 and the early dinosaur Coelophysis in 1889. In 1889...
characteristics (e.g. no secondary palate, small dentary) shared with their pelycosaur ancestors, although they are also more advanced in possessing therapsid...
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