TC-660 (Cambrian of the United States)

Where: Mason County, Texas (30.5° N, 99.1° W: paleocoordinates 16.2° S, 98.2° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Cedaria - Crepicephalus trilobite zone, Cap Mountain Member (Riley Formation), Guzhangian (500.5 - 497.0 Ma)

• local Coosella zone spans Cedaria and Crepicephalus Laurentian trilobite zones

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, fine-grained, medium, glauconitic, brown, gray, silty limestone and lithified siltstone

• brown to gray, fine to medium granular, glauconitic and occasionally oolitic sandy or silty limestone...it can be subdivided into a lower limestone unit [ending at 600 feet in Threadgill Creek section], a middle siltstone and silty limestone unit [ending at 667 feet in Threadgill Creek section], and an upper limestone unit [ending at 792 feet in Threadgill Creek section].

Size class: macrofossils

Collected by A. R. Palmer in the 1940s; reposited in the USNM

Collection methods: mechanical,

Primary reference: A. R. Palmer. 1954. The Faunas of the Riley Formation in Central Texas. Journal of Paleontology 28(6):709-786 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 208759: authorized by Melanie Hopkins, entered by Melanie Hopkins on 10.04.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Trilobita
 Ptychopariida - Tricrepicephalidae
Tricrepicephalus coria
Artiopoda
 Agnostida - Agnostidae
"Kormagnostus simplex" = Kormagnostus seclusus
"Kormagnostus simplex" = Kormagnostus seclusus Walcott 1884
Lingulata
 Acrotretida - Acrotretidae
Opisthotreta depressa n. sp.
Opisthotreta depressa n. sp. Palmer 1954
Kinsabia variegata
  -
Kinsabia variegata
Kinsabia variegata Lochman 1940
unclassified
  -
Porifera indet.
Porifera indet. Grant 1836