Young locality, Delta (MWC–122.1): Late/Upper Kimmeridgian - Early/Lower Tithonian, Colorado
collected by Young 1986

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Heterodontosauridae
cf. Echinodon sp. Owen 1861
Young 1991 1 specimen
tooth fragment
Reptilia
? Coelurosauria indet. (Huene 1914)
Young 1991
tooth fragments
? Aves indet. Linnaeus 1758
Young 1991 1 individual
Reptilia - Prismatoolithidae
Dinosauria indet. Owen 1842
Kirkland 1994
includes eggshell
    = Prismatoolithus coloradensis n. gen., n. sp. Hirsch 1994
Hirsch 1994
recombined as Preprismatoolithus coloradensis
Reptilia - Crocodylia
Crocodylia indet. (Owen 1842)
Young 1991
tooth, scutes, possible egg fragments
Reptilia
Platyognathus sp. Young 1944
Kirkland 1994 1 individual
? Lepidosauria indet. Haeckel 1866
Young 1991
rib and tooth fragments
Reptilia - Sphenodontidae
Young 1991 1 specimen
tooth
Reptilia - Testudines
Testudines indet. Batsch 1788
Kirkland 1994 1 individual
Mammalia - Triconodonta
? Triconodonta indet. Osborn 1888
Young 1991 2 specimens
tooth fragments
Gastropoda - Heterostropha - Valvatidae
Valvata sp. Müller 1774
Young 1991
Bivalvia - Unionida - Unionidae
Unio sp. Philipsson 1788
Young 1991
Ostracoda - Palaeocopida - Amphissitidae
cf. Glyptopleura sp. Girty 1910
Young 1991
Coniferales
Coniferales indet.
Young 1991
"conifer wood"
Polypodiopsida - Equisetales - Equisetaceae
? Equisetum sp. Linnaeus 1753
Young 1991
unclassified
Aclistochara latitruncata Peck 1937
Young 1991
recombined as Latochara latitruncata
see common names

Geography
Country:United States State/province:Colorado County:Delta
Coordinates: 38.8° North, 108.3° West (view map)
Paleocoordinates:34.9° North, 55.3° West
Basis of coordinate:stated in text
Altitude:1561 meters
Geographic resolution:small collection
Time
Period:Jurassic Epoch:Late/Upper Jurassic
Key time interval:Late/Upper Kimmeridgian - Early/Lower Tithonian
Age range of interval:152.20000 - 146.30000 m.y. ago
Stratigraphy
Formation:Morrison Member:Salt Wash
Local section:N-Thoroughfare Local bed:260 ft
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: Approx. 38 m below the top of the Salt Wash Member
Lithology and environment
Primary lithology:brown,red mudstone
Secondary lithology:gray sandstone
Includes fossils?Y
Environment:dry floodplain
Geology comments: "deposited near the distal margin of a riverine fan-like channel system", in a well-drained floodplain
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils
Spatial orientation:life position
Abundance in sediment:abundant
Articulated whole bodies:some
Disassociated major elements:some
Disassociated minor elements:some
Fragmentation:frequent
Temporal resolution:snapshot
Spatial resolution:autochthonous
Collection methods and comments
Collection methods:selective quarrying,surface (float),surface (in situ),field collection
Reason for describing collection:general faunal/floral analysis
Collectors:Young Collection dates:1986
Metadata
Also known as:Wells Gulch, Young egg site
Database number:53021
Authorizer:M. Carrano Enterer:K. Maguire, M. Carrano
Modifier:M. Carrano Research group:vertebrate
Created:2005-08-31 11:56:53 Last modified:2022-04-26 09:20:34
Access level:the public Released:2005-08-31 11:56:53
Creative Commons license:CC BY
Reference information

Primary reference:
15259.ETE K. F. Hirsch, R. G. Young, and H. J. Armstrong. 1987. Eggshell fragments from the Jurassic Morrison Formation of Colorado. In W. R. Averett (ed.), Paleontology and Geology of the Dinosaur Triangle: Guidebook for 1987 Field Trip. Museum of Western Colorado, Grand Junction 79-84 [M. Carrano/M. Carrano]

Secondary references:

15268ETE H. J. Armstrong and E. S. McReynolds. 1987. Stratigraphic correlation of dinosaur quarries near Grand Junction, Colorado. In W. R. Averett (ed.), Paleontology and Geology of the Dinosaur Triangle: Guidebook for 1987 Field Trip. Museum of Western Colorado, Grand Junction 103-106 [M. Carrano/M. Carrano]
15174ETE E. S. Bray and K. F. Hirsch. 1998. Eggshell from the Upper Jurassic Morrison Formation. Modern Geology 23(1-4):219-240 [M. Carrano/M. Carrano]
81461 E. S. Bray and S. G. Lucas. 1997. Theropod dinosaur eggshell from the Upper Jurassic of New Mexico. In S. G. Lucas, J. W. Estep. T. E. Williamson, & G. S. Morgan (eds.), New Mexico’s Fossil Record 1. Bulletin of the New Mexico Museum of Natural History and Science 11:41-43 [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]
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]
14216ETE K. F. Hirsch. 1994. Upper Jurassic eggshells from the Western Interior of North America. In K. Carpenter, K. F. Hirsch, and J. R. Horner (eds.), Dinosaur Eggs and Babies, Cambridge University Press, Cambridge 137-150 [M. Carrano/M. Carrano/M. Carrano]
14332ETE J. I. Kirkland. 1994. Predation of dinosaur nests by terrestrial crocodilians. K. Carpenter, K.F. Hirsch & J.R. Horner (eds.) Dinosaur Eggs and Babies. Cambridge University Press, Cambridge 124-133 [M. Carrano/K. Maguire/M. Carrano]
59745% 15020J. J. Moratalla and J. E. Powell. 1994. Dinosaur nesting patterns. In K. Carpenter, K. F. Hirsch & J. R. Horner (eds.), Dinosaur Eggs and Babies 37-46 [M. Carrano/M. Carrano/M. Carrano]
63745 R. G. Young. 1991. A dinosaur nest in the Jurassic Morrison Formation, western Colorado. In W. R. Averett (ed.), Guidebook for Dinosaur Quarries and Tracksites Tour, Western Colorado and Eastern Utah 1-15 [M. Carrano/M. Carrano/M. Carrano]