PBDB Taxon

Basic info	Taxonomic history	Classification	Included Taxa
Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Secodontosaurus obtusidens

Osteichthyes - Sphenacodontidae

Taxonomy

Theropleura obtusidens was named by Cope (1880). Its type specimen is AMNH 4007, a partial skeleton (fragments of skull and postcrania), and it is a 3D body fossil. Its type locality is Mount Barry, 12 (Admiral Formation), which is in an Artinskian terrestrial shale in the Admiral Formation of Texas.

It was recombined as Dimetrodon obtusidens by Case (1907), Hay (1930); it was recombined as Secodontosaurus obtusidens by Romer (1936), Reisz (1986).

Synonyms

Secodontosaurus willistoni was named by Romer (1936). Its type specimen is FMNH (WM) 573, a partial skull (one maxilla and one dentary), and it is a 3D body fossil. Its type locality is Craddock Bonebed, Brush Creek, 38 (Arroyo Formation), which is in a Kungurian terrestrial claystone/sandstone in the Arroyo Formation of Texas.

It was synonymized subjectively with Secodontosaurus obtusidens by Reisz et al. (1992).
Dimetrodon longiramus was named by Case (1907). Its type specimen is AMNH 4091, a partial skeleton (partial mandible, scapula, vertebrae), and it is a 3D body fossil. Its type locality is Tit Mountain, 21 (Belle Plains Formation), which is in an Artinskian terrestrial claystone/limestone in the Belle Plains Formation of Texas.

It was recombined as Secodontosaurus longiramus by Romer (1936); it was synonymized subjectively with Secodontosaurus obtusidens by Reisz (1986).

Synonymy list

Year	Name and author
1880	Theropleura obtusidens Cope p. 41
1888	Theropleura obtusidens Cope p. 287
1902	Theropleura obtusidens Hay p. 433
1907	Dimetrodon longiramus Case
1907	Dimetrodon obtusidens Case p. 54
1907	Dimetrodon longiramus Case p. 57
1930	Dimetrodon longiramus Hay p. 56
1930	Dimetrodon obtusidens Hay p. 56
1936	Secodontosaurus obtusidens Romer
1936	Secodontosaurus longiramus Romer p. 91
1936	Secodontosaurus willistoni Romer p. 91
1986	Secodontosaurus obtusidens Reisz
1986	Secodontosaurus willistoni Reisz

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
class	Osteichthyes
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha

Rank	Name	Author
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
subclass	Synapsida
suborder	Eupelycosauria
—	Sphenacomorpha	Ivakhnenko 2003
suborder	Sphenacodontia
—	Sphenacodontoidea
family	Sphenacodontidae	Marsh 1878
subfamily	Secodontosaurinae
genus	Secodontosaurus
species	obtusidens	()

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

†Secodontosaurus obtusidens Cope 1880

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Invalid names: Dimetrodon longiramus Case 1907 [synonym], Secodontosaurus willistoni Romer 1936 [synonym]

Diagnosis

No diagnoses are available

Measurements

No measurements are available

Composition:

phosphaticsubp

Environment:

terrestrialuc

Locomotion:

actively mobilec

Created:

2017-04-17 15:15:35

Modified:

2017-04-17 15:15:35

Source: c = class, subp = subphylum, uc = unranked clade

References: Carroll 1988, Kiessling 2004, Hendy et al. 2009

Age range: base of the Artinskian to the top of the Kungurian or 290.10000 to 274.40000 Ma

Collections (5 total)

Time interval	Ma	Country or state	Original ID and collection number
Artinskian	290.1 - 283.3	USA (Texas)	Dimetrodon longiramus (28238) Dimetrodon obtusidens (28149) Theropleura obtusidens (type locality: 28142)
Artinskian - Kungurian	290.1 - 274.4	USA (Texas)	Dimetrodon obtusidens (28253)
Kungurian	283.3 - 274.4	USA (Texas)	Secodontosaurus willistoni (28267)