Dry Mesa Quarry [BYU]: Late/Upper Kimmeridgian - Early/Lower Tithonian, Colorado
collected by E. Jones, V. Jones, J. Jensen 1971–1990

List of taxa
Where & when
Taphonomy & methods
Metadata & references
Taxonomic list
Actinopteri - Palaeonisciformes - Palaeoniscidae
? Palaeoniscidae indet. Vogt 1852
Jensen and Padian 1989 2 elements
Dipnoi indet. (Müller 1884)
Jensen 1984 1 element
    = Ceratodus sp. Agassiz 1838
Britt 1991
Reptilia - Testudines - Pleurosternidae
Dinochelys whitei Gaffney 1979
Brinkman et al. 2000 1 specimen
BYU 13099, skeleton exposed in dorsal and ventral views
Chelonia indet. (Latreille 1800)
Jensen 1984 1 individual
    = Glyptops sp. Marsh 1890
Britt 1991
Reptilia - Archosauria
Archosauria indet. Cope 1869
Jensen and Padian 1989 3 specimens
BYU 9514-9516
Sauropoda indet. (Marsh 1878)
4 specimens
(2 measurements)
    = "Supersaurus" sp. Jensen 1985
Anonymous 1979
    = Supersaurus vivianae n. gen., n. sp. Jensen 1985
Jensen 1985
BYU 5500 (type), plus BYU 5501, 5502, 5503, and 5504
Dystylosaurus edwini n. gen., n. sp. Jensen 1985
Jensen 1985 1 specimen
synonym of Supersaurus vivianae
BYU 5750
"Ultrasaurus" sp. Jensen 1985
Anonymous 1979 1 specimen
BYU 5000 (type) plus BYU 5001, 5002, and 5003 (1 measurement)
    = Ultrasaurus macintoshi n. gen., n. sp. Jensen 1985
Jensen 1985
synonym of Supersaurus vivianae
Barosaurus sp. Marsh 1890
Britt 1991
Diplodocoidea indet. Upchurch 1995
Jensen 1985 1 specimen
    = Diplodocus sp. Marsh 1878
Britt 1991
Apatosaurus sp. Marsh 1877
Britt 1991 2 individuals
Reptilia - Camarasauridae
Camarasaurus sp. Cope 1877
Britt 1991 5 individuals
BYU VP 8967, 13007, 16953, 17465
Reptilia - Avetheropoda
Carnosauria indet. Huene 1920
Jensen and Padian 1989 1 specimen
Reptilia - Avetheropoda - Allosauridae
Allosaurus fragilis Marsh 1877
Britt 1991 200 specimens
MNI = 4
Reptilia - Avetheropoda
Archaeopteryx sp. Meyer 1861
Jensen 1981 1 specimen
BYU 2023, right femur
    = Maniraptora indet. Gauthier 1986
Jensen and Padian 1989
Palaeopteryx thomsoni n. gen., n. sp.
Jensen 1981 1 specimen
nomen dubium belonging to Maniraptora
BYU 2022 (holotype), identified as proximal left tibiotarsus
Reptilia - Avetheropoda - Dromaeosauridae
? Dromaeosauridae indet. Colbert and Russell 1969
Britt 1991 4 specimens
Reptilia - Avetheropoda
? Coelurus sp. Marsh 1879
Britt 1991
    = cf. Coelurus sp. Marsh 1879
Miller et al. 1991
Reptilia - Avetheropoda - Compsognathidae
? Ornitholestes sp. Osborn 1903
Britt 1991 1 specimen
Reptilia - Avetheropoda
Stokesosaurus clevelandi Madsen 1974
Jensen 1984 3 specimens
    = cf. Stokesosaurus sp. Madsen 1974
Britt 1991
    = Stokesosaurus sp. Madsen 1974
Miller et al. 1991
Reptilia - Megalosauridae
Theropoda indet. (Marsh 1881)
3 individuals
67 specimens
    = Torvosaurus tanneri n. gen., n. sp. Galton and Jensen 1979
Galton and Jensen 1979
Reptilia - Piatnitzkysauridae
Marshosaurus bicentesimus Madsen 1976
Jensen 1984 1 specimen
    = cf. Marshosaurus sp. Madsen 1976
Britt 1991
    = Marshosaurus sp. Madsen 1976
Miller et al. 1991
Ceratosaurus nasicornis Marsh 1884
Jensen 1984 25 specimens
    = Ceratosaurus ? nasicornis Marsh 1884
Britt 1991
    = Ceratosaurus sp. Marsh 1884
Miller et al. 1991
Ankylosauria indet. Osborn 1923
Kirkland et al. 1998 1 specimen
Reptilia - Stegosauridae
Stegosaurus sp. Marsh 1877
Britt 1991 1 specimen
Reptilia - Dryosauridae
Dryosaurus sp. Marsh 1894
Jensen 1984 4 individuals
MOR-90-03-Jr-H; BYU 13050, 725/13252, 883
    = Dryosaurus altus Marsh 1878
Horner et al. 2009
Camptosaurus sp. Marsh 1885
Britt 1991 4 specimens
MNI = 1
? Othnielia sp. Galton 1977
Britt 1991 1 specimen
nomen dubium belonging to Ornithopoda
? Pterodactyloidea indet. Plieninger 1901
Jensen and Padian 1989 2 specimens
BYU 9509, 9510, femora
Aves indet. Linnaeus 1758
Jensen 1981 45 specimens
BYU 2024, synsacrum. BYU 2025, left femur
    = Mesadactylus ornithosphyos n. gen., n. sp. Jensen and Padian 1989
Jensen and Padian 1989
BYU 2025, 2500-2501, 9126, 9483-9489, 9490-9499, 9500-9508, 9511, 10023-10025, 10033, 11463, 13033, 13595, 13618, 17206, 17207, 17214, isolated cranial and postcranial elements
Pterodactyloidea indet. Plieninger 1901
Jensen and Ostrom 1977 1 specimen
BYU 2500, first left wing-phalanx
    = ? Dsungaripteroidea indet. Young 1964
Unwin and Heinrich 1999
Reptilia - Crocodylidae
Crocodylidae indet. Cuvier 1807
Jensen 1984
Reptilia - Goniopholididae
Eutretauranosuchus delfsi Mook 1967
Smith et al. 2010 1 individual
BYU 17628, complete skull and mandibles
? Squamata indet. Oppel 1811
Jensen 1984 1 specimen
    = ? Lepidosauria indet. Haeckel 1866
Jensen and Padian 1989
BYU 9524, femur
Mammalia indet. Linnaeus 1758
Prothero and Jensen 1983
BYU 2026, distal end of a right humerus
Prototheria indet. Gill 1872
Britt 1991
Mammalia - Multituberculata
Multituberculata indet. Cope 1884
Jensen 1984
? Amphibia indet. Linnaeus 1758
Jensen and Padian 1989 1 specimen
BYU 9513, vertebral centrum
see common names

Country:United States State/province:Colorado County:Montrose
Coordinates: 38.6° North, 108.4° West (view map)
Paleocoordinates:34.7° North, 55.4° West
Basis of coordinate:stated in text
Altitude:2212 meters
Geographic resolution:outcrop
Period:Jurassic Epoch:Late/Upper Jurassic
Key time interval:Late/Upper Kimmeridgian - Early/Lower Tithonian
Age range of interval:155.70000 - 145.00000 m.y. ago
Age estimate:150.2 ± 0.5 Ma (Ar/Ar)
Formation:Morrison Member:Brushy Basin
Stratigraphic resolution:bed
Stratigraphy comments: 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.
Lithology and environment
Primary lithology:medium,coarse conglomeratic sandstone
Includes fossils?Y
Lithology description: "a fine to coarse grained lenticular sandstone"
Geology comments: "a shallow but wide braided stream"
Modes of preservation:body
Lagerst�tten type:concentrate
Degree of concentration:concentrated
Size of fossils:macrofossils,mesofossils
Preservation of anatomical detail:good
Abundance in sediment:abundant
Articulated whole bodies:none
Associated major elements:some
Disassociated major elements:many
Disassociated minor elements:many
Size sorting:well
Temporal resolution:time-averaged
Spatial resolution:parautochthonous
Collection methods and comments
Collection methods:selective quarrying,surface (float),surface (in situ),mechanical,field collection
Collection size:4000 specimens
Reason for describing collection:taxonomic analysis
Collectors:E. Jones, V. Jones, J. Jensen Collection dates:1971–1990
Collection method comments: discovered summer, 1971 by Eddie & Vivian Jones
Also known as:CO-58, DMDQ
Database number:45975
Authorizer:M. Carrano, R. Butler, P. Mannion, R. Benson Enterer:M. Carrano, R. Butler, J. Tennant, R. Benson
Modifier:M. Carrano Research group:vertebrate
Created:2004-12-16 11:43:48 Last modified:2019-09-25 13:38:21
Access level:the public Released:2004-12-16 11:43:48
Creative Commons license:CC BY
Reference information

Primary reference:

65448. Anonymous. 1973. The Great Dinosaur DIscovery 1-8 [M. Carrano/M. Carrano]

Secondary references:

63779 Anonymous. 1977. The Fruita Paleontological Report 1-82 [M. Carrano/M. Carrano]
63736 Anonymous. 1979. Ultrasaurus. Science News 116(5):84 [M. Carrano/M. Carrano]
65427 R. T. Bakker. 1996. The real Jurassic park: dinosaurs and habitats at Como Bluff, Wyoming. In M. Morales (ed.), The Continental Jurassic. Museum of Northern Arizona Bulletin 60:35-49 [M. Carrano/M. Carrano]
44040 D. B. Brinkman, K. Stadtman, and D. Smith. 2000. New material of Dinochelys whitei Gaffney, 1979, from the Dry Mesa Quarry (Morrison Formation, Jurassic) of Colorado. Journal of Vertebrate Paleontology 20(2):269-274 [R. Benson/R. Benson]
13255ETE B. Britt. 1991. Theropods of Dry Mesa Quarry (Morrison Formation, Late Jurassic), Colorado, with emphasis on the osteology of Torvosaurus tanneri. BYU Geology Studies 37:1-72 [M. Carrano/M. Carrano/M. Carrano]
58722 B. B. Britt and B. D. Curtice. 1997. Dry Mesa Quarry. In P. J. Currie & K. Padian (ed.), Encyclopedia of Dinosaurs 196-197 [M. Carrano/M. Carrano/M. Carrano]
13979ETE B. B. Britt and B. G. Naylor. 1994. An embryonic Camarasaurus (Dinosauria, Sauropoda) from the Upper Jurassic Morrison Formation (Dry Mesa Quarry, Colorado). In K. Carpenter, K. F. Hirsch, and J. R. Horner (eds.), Dinosaur Eggs and Babies 256-264 [M. Carrano/K. Maguire/M. Carrano]
15267ETE W. L. Chenoweth. 1987. The great dinosaur discoveries, Dry Mesa, Colorado. In W. R. Averett (ed.), Paleontology and Geology of the Dinosaur Triangle: Guidebook for 1987 Field Trip. Museum of Western Colorado, Grand Junction 101-102 [M. Carrano/M. Carrano]
14744ETE B. D. Curtice and L. J. Curtice. 1996. Death of a dinosaur: a reevaluation of Ultrasauros macintoshi. Journal of Vertebrate Paleontology 16(3, suppl.):29A [M. Carrano/M. Carrano]
9730 B. D. Curtice, K. L. Stadtman, and L. J. Curtice. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). In M. Morales (ed.), The Continental Jurassic. Museum of Northern Arizona Bulletin 60:87-95 [M. Carrano/M. Carrano/M. Carrano]
35044ETE J. Foster. 2005. New sauropod dinosaur specimens found near Moab, Utah, and the sauropod fauna of the Morrison Formation. Canyon Legacy 55:22-27 [M. Carrano/M. Carrano]
15179ETE J. R. Foster. 2003. Paleoecological analysis of the vertebrate fauna of the Morrison Formation (Upper Jurassic), Rocky Mountain region, U.S.A. New Mexico Museum of Natural History and Science Bulletin 23:1-95 [M. Carrano/M. Carrano]
19565ETE J. R. Foster. 2005. New juvenile sauropod material from western Colorado, and the record of juvenile sauropods from the Upper Jurassic Morrison Formation. In K. Carpenter and V. Tidwell (eds.), Thunder-Lizards: The Sauropodomorph Dinosaurs. Indiana University Press, Bloomington 141-153 [M. Carrano/M. Carrano/M. Carrano]
39692 J. R. Foster and D. J. Chure. 2006. Hindlimb allometry in the Late Jurassic theropod dinosaur Allosaurus, with comments on its abundance and distribution. In J. R. Foster & S. G. Lucas (ed.), Paleontology and Geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science Bulletin 36:119-122 [M. Carrano/M. Carrano/M. Carrano]
69484 J. R. Foster and J. E. Peterson. 2016. First report of Apatosaurus (Diplodocidae: Apatosaurinae) from the Cleveland-Lloyd Quarry in the Upper Jurassic Morrison Formation of Utah: abundance, distribution, paleoecology, and taphonomy of an endemic North American sauropod clade. Palaeoworld 25:431-443 [M. Carrano/M. Carrano]
12264ETE P. M. Galton and J. A. Jensen. 1979. A new large theropod dinosaur from the Upper Jurassic of Colorado. Brigham Young University Geology Studies 26(1):1-12 [M. Carrano/M. Carrano/M. Carrano]
63757 C. S. Goodknight, R. G. Young, and S. L. Knutson. 1991. Fourth day supplemental road log from Grand Junction to the Young dinosaur egg locality and the Dry Mesa dinosaur quarry via Sawmill Mesa and Dry Mesa roads. In W. R. Averett (ed.), Guidebook for Dinosaur Quarries and Tracksites Tour, Western Colorado and Eastern Utah 95-101 [M. Carrano/M. Carrano]
49550 M. Hanson and P. J. Makovicky. 2013. A new specimen of Torvoaurus tanneri originally collected by Elmer Riggs. Historical Biology 26(6):775-784 [P. Mannion/J. Tennant/M. Carrano]
14309ETE J. D. Harris and K. Carpenter. 1996. A large pterodactyloid from the Morrison Formation (Late Jurassic) of Garden Park, Colorado. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 1996(8):473-484 [M. Carrano/M. Carrano/M. Carrano]
31566ETE J. R. Horner, A. de Ricqlès, K. Padian and R. D. Scheetz. 2009. Comparative long bone histology and growth of the "hypsilophodontid" dinosaurs Orodromeus makelai, Dryosaurus altus, and Tenontosaurus tillettii (Ornithlschla: Euornithopoda). Journal of Vertebrate Paleontology 29(3):734-747 [M. Carrano/M. Carrano/M. Carrano]
12260ETE J. A. Jensen. 1981. Another look at Archaeopteryx as the world's "oldest" bird. Encyclia 58:109-128 [M. Carrano/M. Carrano/M. Carrano]
30651ETE J. A. Jensen. 1984. Continuing study of new Jurassic/Cretaceous vertebrate faunas from Colorado and Utah. National Geographic Society Research Reports (1975) 16:373-381 [M. Carrano/M. Carrano]
12261ETE J. A. Jensen. 1985. Uncompaghre dinosaur fauna: a preliminary report. The Great Basin Naturalist 45(4):710-720 [M. Carrano/M. Carrano/M. Carrano]
12262ETE J. A. Jensen. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. The Great Basin Naturalist 45(4):697-709 [M. Carrano/M. Carrano/M. Carrano]
33033ETE J. A. Jensen. 1987. New brachiosaur material from the Late Jurassic of Utah and Colorado. Great Britain Naturalist 47(4):592-608 [M. Carrano/M. Oreska]
12259ETE J. A. Jensen and J. H. Ostrom. 1977. A second Jurassic pterosaur from North America. Journal of Paleontology 51(4):867-870 [M. Carrano/M. Carrano/M. Carrano]
12263ETE J. A. Jensen and K. Padian. 1989. Small pterosaurs and dinosaurs from the Uncompahgre fauna (Brushy Basin Member, Morrison Formation; ?Tithonian), Late Jurassic, western Colorado. Journal of Paleontology 63(3):364-373 [M. Carrano/M. Carrano/M. Carrano]
12888ETE J. I. Kirkland, K. Carpenter, A. P. Hunt and R. D. Scheetz. 1998. Ankylosaur (Dinosauria) specimens from the Upper Jurassic Morrison Formation. Modern Geology 23:145-177 [M. Carrano/M. Carrano/M. Carrano]
63749 W. E. Miller, J. L. Baer, K. L. Stadtman and B. B. Britt. 1991. The Dry Mesa Dinosaur Quarry, Mesa County, Colorado. In W. R. Averett (ed.), Guidebook for Dinosaur Quarries and Tracksites Tour, Western Colorado and Eastern Utah 31-46 [M. Carrano/M. Carrano]
10350 G. S. Paul. 1988. Predatory Dinosaurs of the World. Simon & Schuster, New York 1-464 [M. Carrano/M. Carrano/M. Carrano]
14554ETE G. S. Paul. 1988. The brachiosaur giants of the Morrison and Tendaguru with a description of a new subgenus, Giraffatitan, and a comparison of the world's largest dinosaurs. Hunteria 2(3):1-14 [M. Carrano/M. Carrano/M. Carrano]
44681 D. R. Prothero and J. A. Jensen. 1983. A mammalian humerus from the Upper Jurassic of Colorado. Western North American Naturalist 43(4):551-553 [P. Mannion/J. Tennant]
62005 D. K. Smith. 1997. Museum of Earth Science, Brigham Young University. In P. J. Currie & K. Padian (ed.), Encyclopedia of Dinosaurs 457-458 [M. Carrano/M. Carrano]
34558 D. K. Smith, E. R. Allen, R. K. Sanders and K. L. Stadtman. 2010. A new specimen of Eutretauranosuchus (Crocodyliformes; Goniopholididae) from Dry Mesa, Colorado. Journal of Vertebrate Paleontology 30(5):1466-1477 [R. Butler/R. Butler]
12376ETE D. K. Smith, R. K. Sanders, and K. L. Stadtman. 2004. New material of Mesadactylus ornithosphyos, a primitive pterodactyloid pterosaur from the Upper Jurassic of Colorado. Journal of Vertebrate Paleontology 24(4):850-856 [M. Carrano/M. Carrano/M. Carrano]
31723ETE M. P. Taylor. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806 [M. Carrano/M. Carrano]
19567ETE V. Tidwell, K. Stadtman, and A. Shaw. 2005. Age-related characteristics found in a partial pelvis of a Camarasaurus. In K. Carpenter and V. Tidwell (eds.), Thunder-Lizards: The Sauropodomorph Dinosaurs. Indiana University Press, Bloomington 180-186 [M. Carrano/M. Carrano]
13281ETE C. E. Turner and F. Peterson. 1999. Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A. In D. D. Gillette (ed.), Vertebrate Paleontology in Utah, Utah Geological Survey Miscellaneous Publication 99-1:77-114 [M. Carrano/M. Carrano/M. Carrano]
30145 D. M. Unwin and W. D. Heinrich. 1999. On a pterosaur jaw from the Upper Jurassic of Tendaguru (Tanzania). Mitteilungen aus dem Museum für Naturkunde in Berlin, Geowissenschaftliche Reihe 2:121-134 [R. Butler/R. Butler]
55126 O. Wings. 2015. The rarity of gastroliths in sauropod dinosaurs – a case study in the Late Jurassic Morrison Formation, western USA. Fossil Record 18(1):1-16 [M. Carrano/M. Carrano]