tracksite, 2 miles northwest of Golden (Cretaceous to of the United States)

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)

• Mehl 1931: footprints from the "base of the upper massive sandstone of the "Dakota". It is thought that the specimens here described are definitely Dakota in age, coming as they did from the base of the upper massive sandstone of the series. The impressions were formed in the very top of the immediately underlying shales and it might therefore be argued that they are "pre-Dakota", providing the underlying shale is interpreted as Comanchean as outlined in earlier paragraphs."

• bed-level stratigraphic resolution

Environment/lithology: coastal; sandstone and shale

• The trace fossil evidence suggests a mosaic of coastal plain depositional environments.

Size class: macrofossils

Preservation: mold/impression, trace

Collection methods: Museum: University of Missouri collections.

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 61429: authorized by John Alroy, entered by Susanna Kümmell on 11.06.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Crocodylia -
"Walteria jeffersonensis n. gen. n. sp." = Mehliella jeffersonensis
"Walteria jeffersonensis n. gen. n. sp." = Mehliella jeffersonensis Mehl 1931 crocodilian
regarded as dubious by Lockley et al. 1992