Riggs Quarry 15, Fruita (FMNH) (Jurassic to of the United States)

Also known as CO-36, Dinosaur Hill Quarry

Where: Mesa County, Colorado (39.1° N, 108.7° W: paleocoordinates 35.1° N, 55.4° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Brushy Basin Member (Morrison Formation), Kimmeridgian to Kimmeridgian (157.3 - 145.0 Ma)

• "probably equivalent to Como Beds of Wyoming"; 198 ft below top of member

• bed-level stratigraphic resolution

Environment/lithology: levee; concretionary, green, red, blue claystone and sandstone

• overbank-levee in a well-drained floodplain
• "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. Riggs in 1900-1901; reposited in the FMNH

Collection methods: quarrying, mechanical,

Primary reference: E. S. Riggs. 1903. The vertebral column of Brontosaurus. Science 17(427):393-394 [M. Carrano/M. Oreska]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 36576: authorized by Matthew Carrano, entered by Matthew Carrano on 05.02.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

 Saurischia - Diplodocidae
Diplodocus sp. Marsh 1878 diplodocine
femur, found by Al Look in 1930
Brontosaurus excelsus Marsh 1879 diplodocid
11 presacral, 5 sacral, 23 caudal vertebrae, pelvis, ribs, and chevrons