PBDB Collection

Thrinaxodon Col (Fremouw Formation) (Triassic of Antarctica)

Also known as Mount Kenyon; Cumulus Hills

Where: Antarctica (85.1° S, 174.8° W: paleocoordinates 81.8° S, 69.8° E)

• coordinate stated in text

• local area-level geographic resolution

When: Lystrosaurus zone, Fremouw Formation (Beacon Group), Early/Lower Triassic (252.2 - 247.2 Ma)

• "Thrinaxodon Col section in the Cumulus Hills" (Cosgriff et al., 1982);

•According to Collinson et al. (2006, GSA Bull. 118(5/6) fig. 6) Lystrosaurus occurs in three different levels within the Thrinaxodon Col section but no horizon is given for any particular specimen in Cosgriff et al. (1982) or elsewhere.

• member-level stratigraphic resolution

Environment/lithology: fluvial; medium-grained sandstone and gray, green mudstone

• Lithology and environmental data are from Collinson et al. (2006, GSA Bull. 118(5/6))

Size class: macrofossils

Preservation: mold/impression

Collected by J. W. Kitching in 1969-1970, 1970-1971; reposited in the AMNH

Primary reference: J. W. Cosgriff, W. R. Hammer, and W. J. Ryan. 1982. The Pangaean reptile, Lystrosaurus maccaigi, in the Lower Triassic of Antarctica. Journal of Paleontology 56(2):371-385 [J. Alroy/R. Whatley/R. Whatley]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 27266: authorized by John Alroy, entered by Robin Whatley on 26.11.2002, edited by Torsten Liebrecht, Richard Butler and Chris Sidor

Creative Commons license: CC BY (attribution)

Taxonomic list

• In their 1975 paper Colbert & Kitching give the same coordinates for the locality Procolophon was collected at ("Mount Kenyon") as they give in their 1977 paper for the Thrinaxodon Col locality (note that longitude in reality is W from GM and not E from GM as stated in the paper). Also, Collinson et al. (2006 fig. 6) list Procolophon among the genera found at the Thrinaxodon Col locality. Hence, the Procolophon specimen from "Mount Kenyon" is included here.

Show authors, comments, and common names

Reptilia
Diapsida - Prolacertidae	Prolacerta broomi¹ Prolacerta broomi¹ Parrington 1935 archosauromorph AMNH 9558, partially preserved skull and postcrania. AMNH 9552, postcranial bones. AMNH 9557, humerus, bone fragments
Parareptilia - Procolophonidae	Procolophon trigoniceps³ Procolophon trigoniceps³ Owen 1876 parareptile AMNH 9507
Osteichthyes
Therapsida -	Cynodontia indet.⁴, Thrinaxodon liorhinus⁴ Cynodontia indet.⁴ Owen 1861 cynodont AMNH 9523, 9554; possibly large representatives of the genus Thrinaxodon Thrinaxodon liorhinus⁴ Seeley 1894 cynodont AMNH 9500, 9516, 9517, 9524, 9528, 9529, 9534, 9553, 9555, 9563, 9570, 9571
Therocephalia -	Rhigosaurus glacialis⁵ Rhigosaurus glacialis⁵ therapsid AMNH 9525, partial skull
Dicynodontia - Lystrosauridae	Lystrosaurus maccaigi Lystrosaurus maccaigi Seeley 1898 dicynodont AMNH 9505; specimen listed as Lystrosaurus sp. in Colbert (1974 p. 5)
Amphibia
Temnospondyli -	Cryobatrachus kitchingi² Cryobatrachus kitchingi² Colbert and Cosgriff 1974 tetrapod AMNH 9556, impression of portion of skull roof (paratype)

¹Colbert 1987; ²Colbert and Cosgriff 1974; ³Colbert and Kitching 1975; ⁴Colbert and Kitching 1977; ⁵Colbert and Kitching 1981