Dvinosauria

Not to be confused with Dinosaur.

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.

Dvinosauria Temporal range: Late Carboniferous - Early Triassic, 279.5–251.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Dvinosaurus primus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Dvinosauria Yates and Warren, 2000
Subgroups
†Trimerorhachidae †Perryella †Timonya †Trypanognathus †Dvinosauroidea †Acroplous †Bermanerpeton[1] †Dvinosaurus †Erpetosaurus? †Isodectes †Kourerpeton †Tupilakosauridae

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):^[2]

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

References

1. Werneburg, R.; Schneider, J. W.; Lucas, S. G. (2021). "The new dvinosaurian Bermanerpeton kinneyi (Temnospondyli), with "branchiosaurid" characters, from the Late Pennsylvanian Kinney Brick Quarry in New Mexico". New Mexico Museum of Natural History and Science Bulletin. 84: 433–451.
2. Englehorn, J.; Small, B.J.; Huttenlocker, A. (2008). "A redescription of Acroplous vorax (Temnospondyli: Dvinosauria) based on new specimens from the Early Permian of Nebraska and Kansas, U.S.A.". Journal of Vertebrate Paleontology. 28 (2): 291–305. doi:10.1671/0272-4634(2008)28[291:AROAVT]2.0.CO;2.

• Laurin, M. and Steyer, J-S (2000) Phylogeny and Apomorphies of Temnospondyls. Archived 2005-04-14 at the Wayback Machine, 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