Also known as CO-58, DMDQ, DMQ

Where: Montrose County, Colorado (38.6° N, 108.4° W: paleocoordinates 34.7° N, 55.4° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Brushy Basin Member (Morrison Formation), Late/Upper Kimmeridgian to Late/Upper Kimmeridgian (155.7 - 145.0 Ma)

• upper part of Morrison, near base of member; 30-45 m below base of overlying Cedar Mountain Fm.

•The base of the quarry is about 1 metre above the "clay change". "Sediments near the clay change were dated at 150.3 +/- 0.26 Ma based on Ar40/Ar39 data from plagioclase crystals. Therefore the quarry must be younger than that, close to 150.2 +/- 0.5 Ma. More recent U-Pb dates from this part of the Morrison resulted in 151.2 +/- 1.2 Ma" (Smith et al. 2010. JVP 30:1466). These radiometric dates bracket the Kimmeridgian/Tithonian boundary, and so a late Kimmeridgian-early Tithonian age is entered.

•

• bed-level stratigraphic resolution

Environment/lithology: "channel"; medium-grained, coarse, conglomeratic sandstone

Size classes: macrofossils, mesofossils

Collected by E. Jones, V. Jones, J. Jensen in 1971–1990

Collection methods: quarrying, surface (float), surface (in situ), mechanical,

• discovered summer, 1971 by Eddie & Vivian Jones

Primary reference: Anonymous. 1973. The Great Dinosaur DIscovery. 1-8 [M. Carrano/M. Carrano/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 45975: authorized by Matthew Carrano, entered by Matthew Carrano on 16.12.2004, edited by Richard Butler, Roger Benson and Jonathan Tennant

Creative Commons license: CC BY (attribution)