After Carroll, 1988, with species from “The Paleobiology Database”
<==o †Ophiacodontidae Nopska, 1923 |-- †Archaeothyris florensis Reisz, 1972 `--+--o †Baldwinonus Romer & Price, 1940 | |-- †B. trux Romer & Price, 1940 [AMNH-4780] | `-- †B. dunkardensis Romer, 1952 |--o †Clepsydrops Cope, 1875 [Archaeobelus] | |?- †C. sp. [AMNH-4600] | |-- †C. collettii Cope, 1875 | |-- †C. limbatus Cope, 1877 | |-- †C. natalis Cope, 1878 | `-- †C. vinslovii Cope, 1877 |--o †Ophiacodon Marsh, 1878 [Arribasaurus, Theropleura, Poliosaurus, Winfieldia, Therosaurus, Diopeus] [6 valid species??] | |?- †O. triangulata [AMNH-4167] | |?- †O. watsoni [Therosaurus watsoni [AMNH-4604]] | |?- †O. sp. [AMNH-24800] | |-- †O. major Romer & Price, 1940 [AMNH-21047] | |-- †O. uniformis (Cope, 1878) Romer & Price, 1940 [Poliosaurus] | |-- †O. mirus Marsh, 1878 [AMNH-2900] | |-- †O. navajovicus Romer & Price, 1940 [AMNH-4776] | |-- †O. retroversus Romer & Price, 1940 [AMNH-21063] | `-- †O. hilli Romer & Price 1940 |?- †Protoclepsydrops haplous Carroll, 1964 [P. haplodus?] |-- †Stereophallodon ciscoensis Romer, 1937 [AMNH-4768] |-- †Stereorhachis dominans Gaudry, 1880 `--o †Varanosaurus Broili, 1904 [Poecilospondylus Case, 1910] [jr. syn. to Varanops??; listed as Varanopid by Carroll (1988)] |?- †V. sp. [AMNH-24582] |?- †V.? sp. [AMNH-24583] `-- †V. agutirostris Broili, 1904 [Poecilospondylus francisi Case, 1910; Varanosaurus wichitaensis Romer, 1937]
Reference(s):
- Berman, D. S., Henrici, A. C., Sumida, S. S. & Martens, T., 2000: Redescription of Seymouria sanjuanensis (Seymouriamorpha) from the Lower Permian of Germany based on complete, mature specimens with a discussion of paleoecology of the Bromacker locality assemblage.
–Journal of Vertebrate Paleontology: Vol. 20, #2, pp. 253-268 - Berman, D. S., Reisz, R. R., Bolt, J. R. & Scott, D., 1995: The cranial anatomy and relationships of the synapsid Varanosaurus (Eupelycosauria: Ophiacodontidae) from the Early Permian of Texas and Oklahoma.
–Annals of Carnegie Museum: Vol. 64, #2, pp. 99-133 - Carroll, R. L., 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698 - Carroll, R. L., 1988: Appendix. 594-648.
in Carroll, R. L. 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698 - Laurin, M. & Reisz, R. R., 1997-1998: Synapsida – Mammals and their extinct relatives.
–iNet: The Tree of Life: http://tolweb.org/tree/eukaryotes/animals/chordata/synapsida.html - Laurin , M. & Reisz, R. R., 1997: Autapomorphies of the main clades of synapsids.
–iNet: The Tree of Life: http://tolweb.org/tree/eukaryotes/animals/chordata/synapsidlichen/synapsidasynapomorphies.html
Special thanks to:
Jos H. M. Dols, for gathering additional information and species of these animals.