Collinson Ridge (Fremouw Fm., 85 m above base) (Triassic of Antarctica)

Also known as Cumulus Hills; Halfmoon Bluff; Sentinel Hill

Where: Antarctica (85.2° S, 175.5° W: paleocoordinates 81.8° S, 69.3° E)

• coordinate estimated from map

• small collection-level geographic resolution

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

• "lower portion of the Fremouw Formation, of Early Triassic age" (Colbert & Kitching, 1975);

•According to fig. 10 in Collinson et al. (2006, GSA Bull. 118(5/6)) Procolophon and associate vertebrate remains come from about 85 m above the base of the Fremouw Fm.

• bed-level stratigraphic resolution

Environment/lithology: fluvial; gray, green mudstone

• "Late Permian and Triassic rocks in the central Transantarctic Mountains were deposited in a retroarc foreland basin (Dalziel and Elliot, 1982; Collinson, 1990, 1991; Isbell, 1991; Collinson et al., 1994)." (Collinson et al., 2006 p. 749); "The entire Upper Permian and Lower to Middle Triassic fluvial sequence in the central Transantarctic Mountains was deposited by low-sinuosity braided streams (Barrett et al., 1986)." (Collinson et al., 2006 p. 757)
• lithology is inferred from fig. 10 in Collinson et al. (2006, GSA Bull. 118(5/6))

Size class: macrofossils

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

• "All specimens were collected by J. W. Kitching, except AMNH 9509, collected by Thomas Rich, and AMNH 9510, collected by John Ruben." (Colbert & Kitching, 1975)

Primary reference: E. H. Colbert and J. W. Kitching. 1975. The Triassic Reptile Procolophon in Antarctica. American Museum Novitates 2566:1-23 [J. Mueller/T. Liebrecht]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 87414: authorized by Johannes Mueller, entered by Torsten Liebrecht on 17.03.2009, edited by Richard Butler and Bethany Allen

Creative Commons license: CC BY (attribution)

Taxonomic list

Osteichthyes
 Temnospondyli -
Cryobatrachus kitchingi2 Colbert and Cosgriff 1974 tetrapod
AMNH 9541
Reptilia
 Procolophonia - Procolophonidae
Procolophon trigoniceps Owen 1876 parareptile
AMNH 9518 (two partial skulls), 9533 (badly crushed skull)
 Eosuchia - Prolacertidae
Prolacerta broomi1 Parrington 1935 archosauromorph
AMNH 9520, 9521, 9522, 9526, 9551, 9574
Osteichthyes
 Therapsida - Lystrosauridae
Lystrosaurus curvatus5 Owen 1876 dicynodont
AMNH 9515, partial skull
 Therocephalia - Akidnognathidae
Akidnognathidae indet.4 Nopcsa 1923 therapsid
AMNH FARB 9527, partial skull
 Tetrapoda -
? Austrobrachyops jenseni3 Colbert and Cosgriff 1974 tetrapod
USUOM 31404, 31430