| Dissorophoidea | |
|---|---|
 | |
| Skeleton ofCacops aspidephorus (Dissorophidae) in theField Museum | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Order: | †Temnospondyli |
| Suborder: | †Euskelia |
| Superfamily: | †Dissorophoidea Bolt, 1969 |
| Subgroups | |
See text. | |
Dissorophoidea is aclade of medium-sized,temnospondylamphibians that appeared during theMoscovian inEuramerica, and continued through to theLate Permian and theEarly Triassic ofGondwana. They are distinguished by various details of the skull,[2] and many species seem to have been well adapted for life on land.
Dissorophoid diversity was highest in the Permian; some of the more diverse families within the group includeDissorophidae (toad-like amphibians with armored scutes along their backbone),Trematopidae (terrestrial predators with large triangular skulls), andBranchiosauridae (smallneotenic amphibians with large external gills). The small Permo-CarboniferousMicromelerpetontidae are another example of neotenic dissorophoids. Many small dissorophoids with short rounded skulls were historically known as "amphibamids"; in 2018, the nameAmphibamiformes was erected for a clade equivalent to the broad historical definition of "Amphibamidae".[3]
Since 2008, a consensus of early amphibian researchers considerLissamphibia (modern amphibians) to be part of this clade. There is a large degree of similarity between lissamphibians (for which the oldest known fossils are Early Triassic) and certain Early Permianamphibamiforms, such asGerobatrachus andDoleserpeton.[1][4][3][5] A few authors still dispute affinities between dissorophoids and lissamphibians.[6][7]
An extensive phylogenetic analysis of dissorophoids conducted in 2016 and 2018 found that the familiesDissorophidae andTrematopidae are more closely related to each other than either is to the familyAmphibamidae. Following a 2008 study, the Dissorophidae-Trematopidae clade was calledOlsoniformes. Below is thecladogram from the 2018 analysis:[3]
| Dissorophoidea | |
