ammonites
Ninemile Shale, Antelope Valley (Ordovician of the United States)

Where: Nevada (39.0° N, 116.0° W: paleocoordinates 5.4° S, 83.3° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Presbynileus ibexensis - Pseudocybele nasuta trilobite zone, Ninemile Shale Formation, Blackhillsian (478.6 - 471.8 Ma)

• Listed as Lower Arenig; local series zone I / zone J

• group of beds-level stratigraphic resolution

Environment/lithology: slope; poorly lithified, brown, green shale and poorly lithified, concretionary packstone

• "Slope-forming shale"; "Deeper water, outer shelf or uppermost slope"; zone 5
• Dark green to greenish-brown shale interbedded with thin, nodular, fossiliferous packstone or rare grainstone beds

Size classes: macrofossils, mesofossils

Preservation: trace, concretion

Primary reference: J. Sprinkle and T. E. Guensburg. 1995. Origin of echinoderms in the Paleozoic evolutionary fauna: the role of substrates. Palaios 10:437-453 [G. Webster/G. Webster] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 77185: authorized by Phil Novack-Gottshall, entered by Paul Hearn on 28.12.2007