Lower Coal Sequence (Unit 3, 160 - 199 meters) North Horn Mountain (Cretaceous of the United States)

Also known as KT Boundary Interval (North Horn Formation)

Where: Emery County, Utah (39.3° N, 111.3° W: paleocoordinates 47.1° N, 88.2° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: North Horn Formation, Late/Upper Maastrichtian (70.6 - 66.0 Ma)

• This fossil assemblage consists of collections from different stratigraphic levels; fossils are collected from between 160 and 199 meters (Lower Coal Sequence, Unit 3 from the base of the North Horn Formation at North Horn Mountain.

• group of beds-level stratigraphic resolution

Environment/lithology: fluvial-lacustrine; sandstone

• "represents a paleoenvironment of shallow ephemeral lakes and streams dissecting swampy wetlands...in a tectonically subsiding basin"
• "The lower coal sequence chiefly consists of thinly bedded, high-organic rocks and carbonate rocks interbedded with sandstones and thin coals."

Size classes: macrofossils, microfossils

Collection methods: surface (in situ), chemical, mechanical, sieve,

Primary reference: R. Difley and A. A. Ekdale. 1999. Biostratigraphic aspects of the Cretaceous-Tertiary (KT) boundary interval at North Horn Mountain, Emery County, Utah. Utah Geological Survey Miscellaneous Publication 99-(1):389-398 [J. Alroy/R. Whatley/P. Holroyd]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 13294: authorized by John Alroy, entered by Robin Whatley on 16.02.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• Palynomorphs are present in this assemblage, but no distinctly Cretaceous species.
Show authors, comments, and common names
unclassified
  -
Strobilochara sp., Retusochara sp., Bisulcocypridea ? nyensis
 Charales - Porocharaceae
Porochara sp.
Porochara sp. Maedler 1955
 Charales - Characea
Platychara compressa
Platychara compressa Knowlton 1888
Reptilia
 Dinosauria -
Dinosauria indet.
Dinosauria indet. dinosaur
three forms known from three eggshell types, plus dinosaur bone fragments
Ostracoda
 Podocopida - Cyprididae
Pseudocypridina cf. longa
Gastropoda
 Heterostropha - Physidae
Physa sp.
Physa sp. Draparnaud 1801 snail
 Architaenioglossa - Viviparidae
Lioplacodes sp.
Lioplacodes sp. Meek and Hayden 1864 snail