Dissorophoidea

Dissorophoidea Temporal range: Late Carboniferous - Early Triassic, 310–249 Ma Possible descendant taxon Lissamphibia survives to present. PreЄ Є O S D C P T J K Pg N
Skeleton of Cacops aspidephorus in the Field Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Euskelia
Superfamily:	†Dissorophoidea Bolt, 1969
Clades
Dissorophidae Amphibamidae Trematopidae Micromelerpetontidae Branchiosauridae Melosauridae

Dissorophoideans are a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and even possibly the Early Triassic of Gondwana (if Micropholis belongs here). They are distinguished by various details of the skull,^[1] and many forms seem to have been well adapted for life on land.

It has been suggested that they may be ancestral to the Frogs (Reisz, no date) or even the Lissamphibia as a whole, in which case the latter would be included in this clade.

It is possible that the small Permo-Carboniferous Micromelerpetontidae and the large Late Permian Melosauridae may also belong in this clade.

Phylogeny

An extensive phylogenetic analysis of dissorophoids conducted in 2012 found that the families Dissorophidae and Trematopidae are more closely related to each other than either is to the family Amphibamidae. Following a 2008 study, the Dissorophidae-Trematopidae clade was called Olsoniformes. Below is the cladogram from the 2012 analysis:^[2]

Dissorophoidea

Micromelerpetontidae Micromelerpeton Amphibamidae Platyrhinops Doleserpeton Olsoniformes Trematopidae Ecolsonia Fedexia Tambachia Anconastes Phonerpeton Acheloma Dissorophidae Platyhystrix Aspidosaurus Conjunctio Dissorophinae Dissorophus Broiliellus texensis Broiliellus brevis Broiliellus olsoni Eucacopinae Brevidorsum Admiral taxon Rio Arriba taxon Cacops morrisi Cacops aspidephorus Kamacops Zygosaurus

References and Reliable Link References

• Huttenlocker, Adam. 2007. Dissorophoidea Tree of Life Web Project
• Laurin, M. and Steyer, J-S, 2000, Phylogeny and Apomorphies of Temnospondyls Tree of Life Web Project (reviewed)
• Reisz, Robert, (no date), Biology 356 - Major Features of Vertebrate Evolution - The Origin of Tetrapods and Temnospondyls

External links

• Dissorophoidea - Palaeos
• Dissorophoidea - Mikko's Phylogeny Archive

References

1. (see Laurin & Steyer, 2000, for list of apomorphies)
2. Schoch, Rainer R. (2012). "Character distribution and phylogeny of the dissorophid temnospondyls" (PDF). Fossil Record 15 (2): 121–137. doi:10.5194/fr-15-121-2012. ISSN 1435-1943.