Gordon Valley (Triassic of Antarctica)

Where: Antarctica (84.3° S, 164.1° E: paleocoordinates 76.9° S, 79.5° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Upper Member (Fremouw Formation), Anisian (247.2 - 242.0 Ma)

• Correlated to the Cynognathus Assemblage Zone Subzone C of southern Africa, and thus Anisian in age. Fauna occurs at the base of the "upper" member of the Fremouw Formation

• member-level stratigraphic resolution

Environment/lithology: "channel"; lithified, quartzose, intraclastic, silty conglomerate

• Hammer 1995 says "8 meter thick quartzose sandstone containing sizeable logs and siltstone clasts"

•Sidor et al. 2008 says "Most of the clasts in the conglomerate are rounded and are made up of greenish-gray siltstone that is lithologically the same as a siltstone that underlies the bone bed. The elongate clasts in the conglomerate exhibit no preferred orientation; however, the underlying sandstones indicate a general northwest paleocurrent. The clasts range in diameter from 5 mm to about 60 cm, with an average size of 5–10 cm. The conglomerate has a matrix of medium-grained, quartz-rich sand, similar to un- derlying channel sands. The fact that the conglomerate is domi- nated by intraclasts that were derived from underlying siltstones indicates that the transporting flow was carrying locally eroded material that was transported a relatively short distance. The nature of the unit suggests rapid deposition from a large flow of relatively high viscosity and moderate to lower velocity (Krissek et al., 1991). "

Size class: macrofossils

Collected by Hammer in 1985-86; reposited in the AMNH

Collection methods: surface (in situ),

Primary reference: C. A. Sidor, R. Damiani, and W. R. Hammer. 2008. A new Triassic temnospondyl from Antarctica and a review of Fremouw Formation biostratigraphy. Journal of Vertebrate Paleontology 28(3):656-663 [C. Sidor/B. Peecook]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 105296: authorized by Richard Butler, entered by Richard Butler on 18.02.2011, edited by Chris Sidor

Creative Commons license: CC BY (attribution)

Taxonomic list

Osteichthyes
 Temnospondyli -
Antarctosuchus polyodon4 Sidor et al. 2014 tetrapod
AMNH 24411
Kryostega collinsoni Sidor et al. 2008 tetrapod
AMNH 24419, skull fragment
 Therapsida - Cynognathidae
Cynognathidae indet.2 therapsid
AMNH 24407, partial dentary; AMNH 24406, jaw fragment; AMNH 24423, partial right mandible
 Therapsida -
Cynognathus sp.2 Seeley 1895 therapsid
AMNH 24422, left mandible
Diademodon sp.3 Seeley 1895 therapsid
AMNH 24421, skull fragment
 Dicynodontia -
Kannemeyeriiformes indet.1 Huene 1948 dicynodont
AMNH 24403, right maxillary fragment
 Stegocephali - Benthosuchidae
Benthosuchidae indet.5 Efremov 1940 lobe-finned fish
AMNH 24415