Dry Mesa Quarry [BYU] (Jurassic to of the United States)

Also known as CO-58, DMDQ

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

• "a shallow but wide braided stream"
• "a fine to coarse grained lenticular 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]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)

Taxonomic list

Actinopteri
 Palaeonisciformes - Palaeoniscidae
Osteichthyes
 Dipnoi - Ceratodontidae
Ceratodus sp.2 Agassiz 1838 lungfish
Reptilia
 Testudines - Pleurosternidae
Dinochelys whitei1 Gaffney 1979 turtle
BYU 13099, skeleton exposed in dorsal and ventral views
Glyptops sp.2 Marsh 1890 turtle
 Archosauria -
Archosauria indet.8 archosaur
BYU 9514-9516
 Saurischia - Diplodocidae
"Supersaurus vivianae n. gen. n. sp." = Supersaurus vivianae7, "Dystylosaurus edwini n. gen. n. sp." = Supersaurus vivianae7, "Ultrasaurus macintoshi n. gen. n. sp." = Supersaurus vivianae7, Barosaurus sp.2, Diplodocus sp.2, Apatosaurus sp.2
"Supersaurus vivianae n. gen. n. sp." = Supersaurus vivianae7 Jensen 1985 diplodocine
"Dystylosaurus edwini n. gen. n. sp." = Supersaurus vivianae7 Jensen 1985 diplodocine
BYU 5750
"Ultrasaurus macintoshi n. gen. n. sp." = Supersaurus vivianae7 Jensen 1985 diplodocine
BYU 5000 (type) plus BYU 5001, 5002, and 5003
Barosaurus sp.2 Marsh 1890 diplodocine
Diplodocus sp.2 Marsh 1878 diplodocine
Apatosaurus sp.2 Marsh 1877 diplodocid
 Saurischia - Camarasauridae
Camarasaurus sp.2 Cope 1877 camarasaurid
BYU VP 8967, 13007, 16953, 17465
 Avetheropoda -
 Avetheropoda - Allosauridae
Allosaurus fragilis2 Marsh 1877 allosaurid
MNI = 4
 Avetheropoda -
Maniraptora indet.8 Gauthier 1986 coelurosaur
BYU 2023, right femur
Palaeopteryx thomsoni n. gen. n. sp.5 coelurosaur
BYU 2022 (holotype), identified as proximal left tibiotarsus
 Avetheropoda - Dromaeosauridae
? Dromaeosauridae indet.2 Colbert and Russell 1969 coelurosaur
 Avetheropoda -
cf. Coelurus sp.10 Marsh 1879 coelurosaur
 Avetheropoda - Compsognathidae
? Ornitholestes sp.2 Osborn 1903 compsognathid
 Avetheropoda -
Stokesosaurus sp.10 Madsen 1974 coelurosaur
 Saurischia - Megalosauridae
Torvosaurus tanneri n. gen. n. sp.3
Torvosaurus tanneri n. gen. n. sp.3 Galton and Jensen 1979 tetanuran
67 specimens
 Saurischia - Piatnitzkysauridae
Marshosaurus sp.10 Madsen 1976 tetanuran
 Saurischia -
Ceratosaurus sp.10 Marsh 1884 ceratosaur
 Ornithischia -
Ankylosauria indet.9 ornithischian
 Ornithischia - Stegosauridae
Stegosaurus sp.2 Marsh 1877 ornithischian
 Neornithischia - Dryosauridae
Dryosaurus altus4 Marsh 1878 bird foot dinosaur
MOR-90-03-Jr-H; BYU 13050, 725/13252, 883
 Neornithischia -
Camptosaurus sp.2 Marsh 1885 bird foot dinosaur
MNI = 1
? Othnielia sp.2 Galton 1977 bird foot dinosaur
 Pterosauria -
? Pterodactyloidea indet.8 Plieninger 1901 pterosaur
BYU 9509, 9510, femora
Mesadactylus ornithosphyos n. gen. n. sp.8 Jensen and Padian 1989 pterosaur
BYU 2024, synsacrum. BYU 2025, left femur
? Dsungaripteroidea indet.13 pterosaur
BYU 2500, first left wing-phalanx
 Crocodylia - Crocodylidae
Crocodylidae indet.6 Cuvier 1807 crocodile
 Loricata - Goniopholididae
Eutretauranosuchus delfsi12 Mook 1967 crocodilian
BYU 17628, complete skull and mandibles
 Eosuchia -
Mammalia
  -
Mammalia indet.11 Linnaeus 1758 mammal
BYU 2026, distal end of a right humerus
 Prototheria -
Prototheria indet.2 Gill 1872 mammal
 Allotheria -
Multituberculata indet.6 Cope 1884 multituberculate
Amphibia
  -
? Amphibia indet.8 tetrapod
BYU 9513, vertebral centrum