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
cf. Coelurus sp.10 Marsh 1879 coelurosaur
 Avetheropoda - Compsognathidae
? Ornitholestes sp.2 Osborn 1903 compsognathid
 Avetheropoda -
Stokesosaurus sp.10 Madsen 1974 coelurosaur
 Avetheropoda - Dromaeosauridae
? Dromaeosauridae indet.2 Colbert and Russell 1969 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, "? Othnielia sp." = Ornithopoda2
Camptosaurus sp.2 Marsh 1885 bird foot dinosaur
MNI = 1
"? Othnielia sp." = Ornithopoda2 Marsh 1881 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
 Loricata - Goniopholididae
Eutretauranosuchus delfsi12 Mook 1967 crocodilian
BYU 17628, complete skull and mandibles
 Crocodylia - Crocodylidae
Crocodylidae indet.6 Cuvier 1807 crocodile
 Eosuchia -
Mammalia
  -
Mammalia indet.11 Linnaeus 1758 mammal
BYU 2026, distal end of a right humerus
 Theriiformes -
 Allotheria -
Multituberculata indet.6 Cope 1884 multituberculate
Amphibia
  -
? Amphibia indet.8 tetrapod
BYU 9513, vertebral centrum