Automatic taxobox help
Thanks for creating an automatic taxobox. We don't know the taxonomy of "Caseasauria".
  • Is "Caseasauria" the scientific name of your taxon? If you were editing the page "Animal", you'd need to specify |taxon=Animalia. If you've changed this, press "Preview" to update this message.
  • Click here to enter the taxonomic details for "Caseasauria".
Common parameters
  • |authority= Who described the taxon
  • |parent authority= Who described the next taxon up the list
  • |display parents=4 force the display of (e.g.) 4 parent taxa
  • |display children= Display any subdivisions already in Wikipedia's database (e.g. genera within a family)
Helpful links
Temporal range: Early Permian - Middle Permian
Fossil skeleton of Cotylorhynchus romeri
Scientific classification
Unrecognized taxon (fix): Caseasauria
Genera and Families


Caseasauria is one of the two main clades of early synapsids, the other being the Eupelycosauria. Caseasaurs are currently known only from the Permian, and include two superficially different families, the small insectivorous or carnivorous Eothyrididae, and the large herbivorous Caseidae. These two groups share a number of specialised features associated with the morphology of the snout and external naris.

The ancestor of caseasaurs can be traced back to an insect eating or an omnivorous reptile-like synapsid from the Pennsylvanian time of the Carboniferous, possibly resembling Archaeothyris, the earliest known synapsid. The caseasaurs were abundant during the later part of the Early Permian, but by the Middle Permian caseasaur diversity declined because the group was outcompeted by the more successful therapsids. The last caseasaurs became extinct at the end of the Guadelupian (Middle Permian).[1]


Most uncertainty in the phylogeny of synapsids lies among the earliest members of the group, including forms traditionally placed within Pelycosauria. As one of the earliest phylogenetic analyses, Brinkman & Eberth (1983) placed the family Varanopidae with Caseasauria as the most basal ofshoot of the synapsid lineage. Reisz (1986) removed Varanopidae from Caseasauria, placing it in a more derived position on the stem. While most analyses find Caseasauria to be the most basal synapsid clade, the analysis of Benson (2012) placed a clade containing Ophiacodontidae and Varanopidae as the most basal synapsids, with Caseasauria occupying a more derived position. Benson attributed this revised phylogeny to the inclusion of postcranial characteristics, or features of the skeleton other than the skull, in his analysis. When only cranial or skull features were included, Caseasauria remained the most basal synapsid clade. Below is a cladogram modified from the analysis of Benson (2012):[2]

Tseajaia campi

Limnoscelis paludis


Captorhinus spp.

Protorothyris archeri





Ianthodon schultzei



Haptodus garnettensis

Pantelosaurus saxonicus





Eothyris parkeyi

Oedaleops campi


Oromycter dolesorum

Casea broilii

Trichasaurus texensis

Euromycter rutenus (="Casea" rutena)

Ennatosaurus tecton

Angelosaurus romeri

Cotylorhynchus romeri

Cotylorhynchus bransoni

Cotylorhynchus hancocki

See also


  1. ^ Maddin, H.C., Sidor, C.A. & Reisz, R.R. 2008. Cranial anatomy of Ennatosaurus tecton (Synapsida: Caseidae) from the Middle Permian of Russia and the evolutionary relationships of Caseidae. Journal of Vertebrate Paleontology (28): 160-180
  2. ^ Benson, R.J. (2012). "Interrelationships of basal synapsids: cranial and postcranial morphological partitions suggest different topologies". Journal of Systematic Paleontology. in press. doi:10.1080/14772019.2011.631042. 

External links

Template:Basal synapsidsTemplate:Project Synapsid Taxonomy
Community content is available under CC-BY-SA unless otherwise noted.