Biology:Dvinosauria

Short description: Extinct suborder of temnospondyls

Not to be confused with Dinosauria.

Dvinosauria Temporal range: Late Carboniferous - Early Triassic, 279.5–251.3 Ma PreЄ Є O S D C P T J K Pg N
Dvinosaurus primus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	†Temnospondyli
Suborder:	†Dvinosauria Yates and Warren, 2000
Subgroups
†Trimerorhachidae †Perryella †Timonya †Trypanognathus †Dvinosauroidea †Acroplous †Bermanerpeton †Dvinosaurus †Erpetosaurus? †Isodectes †Kourerpeton †Tupilakosauridae

Dvinosaurs are one of several new clades of temnospondyls named in the phylogenetic review of the group by Yates and Warren 2000. They represent a group of primitive semi-aquatic to completely aquatic temnospondyls, and are known from the Late Carboniferous to the Early Triassic, being most common in the Permian period. Their distinguishing characteristics are a reduction of the otic notch; the loss of a flange on the rear side of the pterygoid; and 28 or more presacral vertebrae.

Trimerorhachidae is the most basal family of dvinosaurs. Most other dvinosaurs are placed in the superfamily Dvinosauroidea. Within Dvinosauroidea are two families, Eobrachyopidae and Tupilakosauridae, as well as dvinosaurs that cannot be placed in either family, such as Dvinosaurus and Kourerpeton. A 2008 phylogenetic analysis found Eobrachyopidae to be paraphyletic, representing a grade of basal dvinosauroids. Below is a cladogram showing the phylogenetic relationships of dvinosaurs from Englehorn et al. (2008):

Dvinosauria	Trimerorhachidae   Trimerorhachis     Neldasaurus         Perryella   Dvinosauroidea   Isodectes (Eobrachyopidae)       Acroplous (Eobrachyopidae)       Dvinosauridae     Kourerpetidae   Tupilakosauridae   Slaugenhopia     Tupilakosaurus     Thabanchuia

References

• Laurin, M. and Steyer, J-S (2000) Phylogeny and Apomorphies of Temnospondyls. , The Tree of Life Web Project
• Yates, Adam M.; Warren, A. Anne (2000). "The phylogeny of the ‘higher’ temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of the Stereospondyli". Zoological Journal of the Linnean Society 128 (1): 77–121. doi:10.1111/j.1096-3642.2000.tb00650.x. 

External links

• Temnospondyli: Limnarchia at Palaeos
• Dvinosauria at Mikko's Phylogeny Archive (cladogram based on Yates and Warren 2000)
• Suborder †Dvinosauria - Scientific Hierarchy at the Taxonomicon

Template:Temnospondyli Wikidata ☰ Q3716788 entry