USGS 22191, W of courthouse, Weatherford [Walnut Clay] (Cretaceous of the United States)

Where: Parker County, Texas (32.8° N, 97.8° W: paleocoordinates 30.4° N, 55.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Walnut Clay Formation (Fredericksburg Group), Early/Lower Albian (112.0 - 109.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Walnut Clay Fm, which overlies the Paluxy Fm, and is overlain by the Goodland Fm of the Fredricksburg Gp. AGE: early Middle Albian; early Comanchean, on the basis of ammonite biostratigraphy. STRATIGRAPHIC POSITION: From unknown position in formation.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified claystone

• ENVIRONMENT: Offshore siliciclastic marine setting.
• SPECIFIC LITHOLOGY: LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: Not stated, but presumably the authors. REPOSITORY: USNM, Washington.

Primary reference: W. J. Kennedy, N. H. Landman, and W. A. Cobban. 1998. Engonoceratid ammonites from the Glen Rose Limestone, Walnut Clay, Goodland Limestone, and Comanche Peak Limestone (Albian) in Texas. American Museum Novitates 3221:1-40 [A. Hendy/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 82413: authorized by Austin Hendy, entered by Austin Hendy on 27.07.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited to ammonoidea, although other faunal groups are known to co-occur (though not listed). NOMENCLATURE: Authoritative publication, with modern nomenclature and species-resolution identifications.
Show authors, comments, and common names
Cephalopoda
 Ammonitida - Engonoceratidae
Metengonoceras ambiguum
Metengonoceras ambiguum Hyatt 1903 ammonite