tracksite, north of Golden: Late/Upper Albian - Early/Lower Cenomanian, Colorado
collected by M. G. Mehl

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia
Walteria jeffersoni n. gen., n. sp.
Lockley et al. 2001
replaced by Mehliella
Reptilia - Iguanodontipodidae
Ornithopoda indet. (Marsh 1881)
Lockley et al. 2009 8 specimens
tracks
    = Caririchnium leonardii Lockley 1987
Matsukawa et al. 1999
recombined as Hadrosauropodus leonardii
Reptilia - Ornithomimipodidae
Magnoavipes sp. Lee 1997
Lockley et al. 2006 1 specimen
Reptilia - Ignotornidae
Ignotornis mcconnelli n. gen., n. sp. Mehl 1931
U. Colo. 17614
see common names

Geography
Country:United States State/province:Colorado County:Jefferson
Coordinates: 39.8° North, 105.2° West (view map)
Paleocoordinates:38.9° North, 66.4° West
Basis of coordinate:based on nearby landmark
Time
Period:Cretaceous
Key time interval:Late/Upper Albian - Early/Lower Cenomanian
Age range of interval:106.20000 - 93.90000 m.y. ago
Stratigraphy
Geological group:Dakota Formation:Muddy Sandstone
Local section:"Upper sandstone" Local bed:5
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: Late Albian-Early Cenomanian; footprints from the very base as the lowest member of the "Upper sandstone". 1 bed, lower stratigraphic level (Lockley et al. 2009)
Lithology and environment
Primary lithology:massive sandstone
Secondary lithology:current ripples,tool marks muddy "shale"
Includes fossils?Y
Lithology description: Buff-colored massive crossbedded sandstone with several shale partings in lower part. Footprints preserved on bottom suface.
Environment:levee
Geology comments: "Ignotornis bird tracks are associated with purported levee deposits"... "the track bearing facies, including parts of the Van Bibber Shale and the J Sandstone, represent a mosaic of coastal plain facies ranging from tidal flats to coal-bearing swamp and levee deposits associated with river systems."
Taphonomy
Modes of preservation:mold/impression,trace
Size of fossils:macrofossils
Temporal resolution:snapshot
Spatial resolution:autochthonous
Collection methods and comments
Collection methods:surface (in situ),field collection,survey of museum collection,observed (not collected)
Reason for describing collection:taxonomic analysis
Museum repositories:UCM
Collectors:M. G. Mehl
Metadata
Also known as:Mehl's bird track locality
Database number:60595
Authorizer:J. Alroy, M. Carrano Enterer:S. Kuemmell, M. Carrano
Modifier:M. Carrano Research group:vertebrate
Created:2006-05-18 07:02:15 Last modified:2019-06-26 15:36:08
Access level:the public Released:2006-05-18 07:02:15
Creative Commons license:CC BY
Reference information

Primary reference:
17712. M. G. Mehl. 1931. Additions to the vertebrate record of the Dakota sandstone. American Journal of Science 21(125):441-452 [J. Alroy/S. Kuemmell/S. Kuemmell]

Secondary references:

69250 P. Brodkorb. 1971. Origin and evolution of birds. In D. S. Farner & J. R. King (ed.), Avian Biology 1:19-55 [M. Carrano/M. Carrano]
64006 P. Brodkorb. 1978. Catalogue of fossil birds. Part 5 (Passeriformes). Bulletin of the Florida State Museum 23(3):139-228 [M. Carrano/M. Carrano/M. Carrano]
69095 J. Y. Kim, M. G. Lockley, S. J. Seo, K. S. Kim, S. H. Kim and K. S. Baek. 2012. A paradise of Mesozoic birds: the world's richest and most diverse Cretaceous bird track assemblage from the Early Cretaceous Haman Formation of the Gajin Tracksite, Jinju, Korea. Ichnos 19:28-42 [M. Carrano/M. Carrano/M. Carrano]
32742ETE M. Lockley, K. Chin, K. Houck, M. Matsukawa, and R. Kukihara. 2009. New interpretations of Ignotornis, the first-reported Mesozoic avian footprints: implications for the paleoecology and behavior of an enigmatic Cretaceous bird. Cretaceous Research 30:1041-1061 [M. Carrano/M. Carrano/M. Carrano]
63566 M. G. Lockley. 1986. A Guide to Dinosaur Tracksites of the Colorado Plateau and American Southwest. University of Colorado at Denver Geology Department Magazine, Special Issue 1:1-56 [M. Carrano/M. Carrano/M. Carrano]
19038ETE M. G. Lockley. 1987. Dinosaur footprints from the Dakota Group of eastern Colorado. The Mountain Geologist 24(4):107-122 [M. Carrano/M. Carrano]
25992ETE M. G. Lockley, J. Holbrook, R. Kukihara and M. Matsukawa. 2006. An ankylosaur-dominated dinosaur tracksite in the Cretaceous Dakota Group of Colorado: paleoenvironmental and sequence stratigraphic context. In S. G. Lucas and R. M. Sullivan (eds.), Late Cretaceous Vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35:95-104 [M. Carrano/M. Carrano]
19046ETE,5% 53960M. G. Lockley, N. Hook, and A. Taylor. 2001. A brief history of paleontological research and public education on Dinosaur Ridge. The Mountain Geologist 38(3):87-95 [M. Carrano/M. Carrano/J. Alroy]
61886 M. G. Lockley and A. P. Hunt. 1995. Dinosaur Tracks and Other Fossil Footprints of the Western United States xxi-338 [M. Carrano/M. Carrano]
174155% 6460M. G. Lockley, S.Y. Yang, M. Matsukawa, F. Fleming, and S.K. Lim. 1992. The track record of Mesozoic birds: evidence and implications. Philosophical Transactions of the Royal Society of London, Series B: Biological Sciences 336:113-134 [J. Alroy/S. Kuemmell/S. Kuemmell]
14666ETE M. Matsukawa, M. G. Lockley, and A. P. Hunt. 1999. Three age groups of ornithopods inferred from footprints in the mid-Cretaceous Dakota Group, eastern Colorado, North America. Palaeogeography, Palaeoclimatology, Palaeoecology 147:39-51 [M. Carrano/K. Maguire/M. Carrano]