SS-24, Simpson Spring Mountains (Cambrian of the United States)

Also known as Marathon Basin, Woods Hollow Boulders Fm., Cedaria Zone, Texas

Where: Texas (30.0° N, 103.3° W: paleocoordinates 12.1° S, 101.2° W)

• coordinate based on political unit

When: Cedaria trilobite zone, Lower Member (Woods Hollow Boulders Formation), Marjumian (513.0 - 498.5 Ma)

• "Cedaria zone."

• member-level stratigraphic resolution

Environment/lithology: offshore shelf; green limestone and shale

• "ls. boulders in dark green shale. outer shelf (BA5)"
• Dark yellowish brown to moderate yellowish brown medium-grain mottled limestone, weathers with orange ferruginous spots and contains lenses of trilobite coquina.

Size classes: macrofossils, mesofossils

Primary reference: J.L. Wilson. 1954. Late Cambrian and Early Ordovician Trilobites from the Marathon Uplift, Texas. Journal of Paleontology 28(3):249-285 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 228: authorized by Jack Sepkoski, entered by Mike Sommers on 20.11.1998, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• "J.L.Wilson 1954. Late Camb. and early Ord. trilobites from the Marathon Uplift, Texas. J. Paleo 28:249-285."
Trilobita
 Agnostida - Agnostidae
Kormagnostus sp. Resser 1938 trilobite
 Aulacopleurida - Marjumiidae
 Aulacopleurida - Crepicephalidae
Coosia pernamagna Wilson 1954 trilobite
 Olenida - Cedariidae
Cedaria sp. Walcott 1924 trilobite
 Olenida - Asaphiscidae
 Ptychopariida - Kingstoniidae
Blountia sp. Walcott 1916 trilobite
2 species
Blountia ovata trilobite