Name: Seymouria
(From
Seymour).
Phonetic: See-more-ee-ah.
Named By: Broili - 1904.
Synonyms: Conodectes, Desmospondylus.
Classification: Chordata, Tetrapoda, Amphibia,
Labyrinthodontia, Reptiliomorpha, Seymouriamorpha, Seymouriidae.
Species: S. baylorensis (type),
S.
sanjuanensis,
S. graandis.
Diet: Carnivore.
Size: 60 centimetres long.
Known locations: USA - Colorado, Oklahoma, Texas,
Utah. Germany.
Time period: Early Permian.
Fossil representation: Numerous well preserved
specimens, including two laying side by side.
Although it had several reptilian features, Seymouria was actually an amphibian. This creature displays a strong backbone and muscle growth for movement on land, and hearing adapted for use out of water. It’s possible that its preferred form of locomotion would have been a side to side undulating motion like modern lizards, this action would increase the reach of the limbs. Despite these adaptations it has been hypothesised that Seymouria still had to return to the water for spawning. There appears to be some sexual dimorphism in that males had thicker skulls.
Further reading
- Restoration of Seymouria baylorensis Broili, an
American Cotylosaur.
- The Journal of Geology. 19 (3): 232–237. - S. W. Williston - 1911.
- On Seymouria, the most primitive known reptile. -
Proceedings of the
Zoological Society of London. 88 (3–4): 267–301 - D. M. S. Watson -
1918.
- A Skeletal Model of the Primitive Reptile Seymouria,
and the
Phylogenetic Position of that type. - The Journal of Geology. 36 (3) -
Alfred S. Romer - 1928.
- Osteology of Seymouria baylorensis Broili. -
Bulletin of the Museum
of Comparative Zoology. 85 (5). - T. E. White - 1939.
- Seymouria from the Lower Permian of Southeastern
Utah, and Possible
Sexual Dimorphism in That Genus. - Journal of Paleontology. 40 (3):
603–612. - Peter Paul Vaughn - 1966.
- Seymouria grandis n. sp. (Batrachosauria:
Amphibia) from the Middle
Clear Fork (Permian) of Oklahoma and Texas. - Journal of Paleontology
53(3):720-728. - E. C. Olsen - 1979.
- Seymouria sanjuanensis (Amphibia, Batrachosauria)
from the Lower
Permian Cutler Formation of north-central New Mexico and the occurrence
of sexual dimorphism in that genus questioned. - Canadian Journal of
Earth Sciences. 24 (9): 1769–1784. - David S. Berman, Robert R. Reisz
& David A. Eberth - 1987.
- Seymouria from the Lower Permian of Southeastern
Utah, and Possible
Sexual Dimorphism in That Genus. - Journal of Paleontology. 40 (3):
603–612. - Laurin Michel - 1996.
- First record of Seymouria (Vertebrata:
Seymouriamorpha) from Early
Permian fissure fills at Richards Spur, Oklahoma. - Canadian Journal of
Earth Sciences. 36 (8). - Corwin Sullivan & Robert R. Reisz -
1999.
- Redescription of Seymouria sanjuanensis
(Seymouriamorpha) from the
Lower Permian of Germany based on complete, mature specimens with a
discussion of paleoecology of the Bromacker locality assemblage. -
Journal of Vertebrate Paleontology. 20 (2). - Davis S. Berman, Amy C.
Henrici, Stuart S. Sumida & Thomas Martens - 2000.
- New structures and reconstructions of the skull of the Seymouriamorph
Seymouria sanjuanensis Vaughn. - Annals of Carnegie
Museum. 74 (4):
217–225. - Jozef Klembara, David S. Berman, Amy C. Henrici, Andrej
Cernansky - 2005
- First description of skull of Lower Permian Seymouria
sanjuanensis
(Seymouriamorpha: Seymouriidae) at an early juvenile growth stage. -
Annals of Carnegie Museum. 76 (1). - Jozef Klembara, David S. Berman,
Amy C. Henrici, Andrej Cernansky, Ralf Werneberg & Thomas
Martens - 2007.
- Postcranial anatomy and histology of Seymouria, and the
terrestriality of seymouriamorphs. - PeerJ. 8: e8698. - Kayla D.
Bazzana, Bryan M. Gee, Joseph J. Bevitt & Robert R. Reisz -
2020.