PTRM V95018 (Silty Mudstone) (Cretaceous of the United States)

Where: Slope County, North Dakota (46.5° N, 104.0° W: paleocoordinates 52.9° N, 77.0° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Hell Creek Formation, Maastrichtian (72.1 - 66.0 Ma)

• "200 cm thick" and "21.10 m below the pollen-defined K/T boundary"

• group of beds-level stratigraphic resolution

Environment/lithology: "floodplain"; silty mudstone

• "The presence of these mud balls indicates an incising current causing stream margin erosion of the flood plain and bank cave-off. This mudstone also represents the adjacent floodplain and preserves leaf impressions... within the silty laminae"
• "silty mudstone deposit with thin siltstone laminae representing the adjacent floodplain" relative to an underlying channel; "the lower part... is 65 cm thick and preserves mud balls along its contact with the sandstone deposit below"

Size class: macrofossils

Preservation: adpression

Collected in 1996 - 2000

• PTRM collection

Primary reference: G. E. Knauss, W. G. Joyce, T. R. Lyson and D. Pearson. 2011. A new kinosternoid from the Late Cretaceous Hell Creek Formation of North Dakota and Montana and the origin of the Dermatemys mawii lineage. Palaeontologische Zeitschrift 85:125-142 [J. Alroy/J. Alroy/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 99589: authorized by John Alroy, entered by John Alroy on 16.11.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

 Testudines - Kinosternoidea
Hoplochelys clark n. sp. Knauss et al. 2011 mud turtle
 Pinales - Taxodiaceae
Sequoia sp. Endlicher 1847 coast redwood
 Rhamnales - Rosidae
 Magnoliales - Lauraceae
 Fagales - Fagaceae