tracksite, north of Golden (Cretaceous to of the United States)

Also known as Mehl's bird track locality

Where: Jefferson County, Colorado (39.8° N, 105.2° W: paleocoordinates 38.9° N, 66.4° W)

• coordinate based on nearby landmark

When: Muddy Sandstone Formation (Dakota Group), Late/Upper Albian to Late/Upper Albian (105.3 - 93.5 Ma)

• 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)

• bed-level stratigraphic resolution

Environment/lithology: levee; massive sandstone and muddy shale

• "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."
• Buff-colored massive crossbedded sandstone with several shale partings in lower part. Footprints preserved on bottom suface.

Size class: macrofossils

Preservation: mold/impression, trace

Collected by M. G. Mehl; reposited in the UCM

Collection methods: surface (in situ), ,

Primary reference: 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]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 60595: authorized by John Alroy, entered by Susanna Kümmell on 18.05.2006, edited by Matthew Carrano

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Crocodylia -
"Walteria jeffersoni n. gen. n. sp." = Mehliella2
"Walteria jeffersoni n. gen. n. sp." = Mehliella2 crocodilian
 Ornithischia - Iguanodontipodidae
"Caririchnium leonardii" = Hadrosauropodus leonardii3
"Caririchnium leonardii" = Hadrosauropodus leonardii3 Lockley 1987 ornithopod
tracks
Aves
  - Ignotornidae
Ignotornis mcconnelli n. gen. n. sp.
Ignotornis mcconnelli n. gen. n. sp. Mehl 1931 bird
U. Colo. 17614
Reptilia
 Theropoda - Ornithomimipodidae
Magnoavipes sp.1 Lee 1997 coelurosaur