ammonites
Riggs Quarry 12, Fruita (FMNH) (Jurassic to of the United States)

Also known as Redlands

Where: Mesa County, Colorado (39.2° N, 108.7° W: paleocoordinates 35.2° N, 55.4° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Brushy Basin Member (Morrison Formation), Kimmeridgian to Kimmeridgian (155.7 - 145.5 Ma)

• described as "lower Como Beds"

• bed-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; green claystone and sandstone

• "variegated clays...alternation between green and purplish bands does not mark andy variation in the nature of hardness of these massive joint clays. There are frequent layers of clay nodules, sometimes calcareous, and a few ledges of nodular gray sandstone which are confined to limited areas. Occasional thick ledges of cross-bedded sandstone and lenticular masses of greenish sand occur at almost all levels, but these are likewise of limited extent. Near the top...the clays take on a more sandy nature." (Riggs 1901)

Size class: macrofossils

Collected by E. S. Riggs, H. W. Mencke, & V. H. Barnett in 1900; reposited in the FMNH

Collection methods: quarrying, mechanical,

• discovered by E. S. Riggs, H. W. Mencke, and V. H. Barnett

Primary reference: E. S. Riggs. 1901. The fore leg and pectoral girdle of Morosaurus, with a note on the genus Camarosaurus. Field Columbian Museum Publication 63, Geological Series 1(10):275-281 [M. Carrano/M. Carrano/J. Alroy] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 11924: authorized by Matt Carrano, entered by Matt Carrano on 19.09.2001

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)