Capitosauria

Capitosauria is an extinct group of large temnospondyl amphibians with simplified stereospondyl vertebrae. Mainly living as piscivores in lakes and rivers, the Capitosauria and its sister taxon Trematosauria were the only major labyrinthodonts that existed during the Mesozoic in ecological niches broadly similar to those of modern crocodiles, and some grew to very large sizes. At 6 meter in length, the Mid-Triassic Mastodonsaurus giganteus is not only thought to have been the largest capitosaur, but possibly also the largest amphibian to have lived.[1] The capitosaurs enjoyed a brief period of success in the Early Triassic, but the rise of phytosaurs and other aquatic archosauriforms in the Middle Triassic caused them to go into decline, and the capitosaur lineage is not known to survive beyond the Late Triassic.[1]

Capitosauria Temporal range: Triassic, 251.902–237 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Mastodonsaurus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Stereospondyli
Clade:	†Capitosauria Schoch and Milner, 2000
Clades
†Mastodonsauroidea

Capitosauria was first named by Schoch and Milner (2000) and further described by Yates and Warren (2000), who assigned Lydekkerina and Mastodonsauroidea to it.[2][3] It was described by Damiani (2001) under the name Mastodonsauroidea.[4] In their phylogenetic analysis of temnospondyls, Ruta et al. (2007) placed Lydekkerina and its relatives within the clade Rhytidostea, while placing only mastodonsauroid taxa within Capitosauria.[5]

Phylogeny

Below is a cladogram from Fortuny et al. (2011) showing the phylogenetic relationships of capitosaurs:[6]

Stereospondyli

Lydekkerina huxleyi   Rhinesuchidae   Rhineceps nyasaensis     Uranocentrodon senekalensis       Capitosauria   Wetlugasaurus angustifrons         Odenwaldia heidelbergensis     Vladlenosaurus alexeyevi             Edingerella madagascariensis     Watsonisuchus spp.         Xenotosuchus africanus       Cherninia denwai       Paracyclotosaurus crookshanki         Stanocephalosaurus pronus     Stanocephalosaurus birdi         Procyclotosaurus stantonensis       Eocyclotosaurus spp.     Quasicyclotosaurus campi                     Parotosuchus orenburgensis       Calmasuchus acri         Cyclotosaurus robustus     Tatrasuchus wildi         Eryosuchus garjainovi     Mastodonsaurus giganteus                 Trematosauria   Benthosuchus sushkini   Trematosauroidea   Thoosuchus yakovlevi       Angusaurus spp.     Trematosaurus brauni

References

1. "Capitosauria". Palaeos. Retrieved 18 June 2014.
2. Schoch, R. R.; Milner, A. R. (2000). "Stereospondyli". In P. Wellnhofer (ed.). Handbuch der Paläoherpetologie. 3B. Munich: Verlag Dr. Friedrich Pfeil. p. 203.
3. Yates, A. M.; Warren, A. A. (2000). "The phylogeny of the "higher" temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of Stereospondyli". Zoological Journal of the Linnean Society. 128: 77–121. doi:10.1111/j.1096-3642.2000.tb00650.x.
4. Damiani, R. J. (2001). "A systematic revision and phylogenetic analysis of Triassic mastodonsauroids (Temnospondyli: Stereospondyli)". Zoological Journal of the Linnean Society. 133 (4): 379–482. doi:10.1111/j.1096-3642.2001.tb00635.x.
5. Ruta, M.; Pisani, D.; Lloyd, G. T.; Benton, M. J. (2007). "A supertree of Temnospondyli: cladogenetic patterns in the most species-rich group of early tetrapods". Proceedings of the Royal Society B. 274 (1629): 3087–3095. doi:10.1098/rspb.2007.1250. PMC 2293949. PMID 17925278.
6. Fortuny, J.; Galobart, À.; Santisteban, C. D. (2011). "A New Capitosaur from the Middle Triassic of Spain and the Relationships within the Capitosauria". Acta Palaeontologica Polonica. 56 (3): 553. doi:10.4202/app.2010.0025.

External links

• Capitosauria in the Paleobiology Database