Barrett #1 (Cretaceous of the United States)

Also known as Black Hills

Where: Wyoming (44.7° N, 104.2° W: paleocoordinates 43.4° N, 53.0° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Cretaceous Formation, Early/Lower Cretaceous (145.0 - 100.5 Ma)

• Due to its 19th century date of publication, the "Cretaceous Formation" is the highest stratigraphic resolution for this collection.

• formation-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; shale

• "Gray and drab-colored clay shales, with local coal seams, [overlying] gray clay shales and sandy shales with plant remains."

Size classes: macrofossils, mesofossils

Preservation: mold/impression, adpression, original carbon

Collection methods: bulk,

Primary reference: L.F. Ward. 1899. The Cretaceous formation of the Black Hills as as indicated by the fossil plants. Cretaceous Formation of the Black Hills [B. Tiffney/J. Fosdick/B. Tiffney]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 32033: authorized by Bruce Tiffney, entered by Julia Fosdick on 01.06.2003

Creative Commons license: CC BY (attribution)

Taxonomic list

Polypodiopsida
  - Polypodiaceae
"Thyrsopteris dentifolia n. sp." = Onychiopsis psilotoides, "Thyrsopteris pecopteroides" = Onychiopsis nervosa, "Thyrsopteris brevifolia" = Onychiopsis brevifolia
"Thyrsopteris dentifolia n. sp." = Onychiopsis psilotoides Stokes and Webb 1824
"Thyrsopteris pecopteroides" = Onychiopsis nervosa Fontaine 1889
"Thyrsopteris brevifolia" = Onychiopsis brevifolia Fontaine 1889