Ludlow (Point Pleasant Tongue) (Ordovician of the United States)

Where: Kenton County, Kentucky (39.1° N, 84.5° W: paleocoordinates 26.6° S, 62.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Clays Ferry Formation, Shermanian (457.3 - 449.6 Ma)

• "base of the Hudson River Group"; Hudson River Group is an old name that is no longer used for the beds of the Upper Ordovician;

•Point Pleasant Tongue of Clays Ferry Fm.

• member-level stratigraphic resolution

Environment/lithology: deep subtidal shelf; shelly/skeletal limestone and shale

• " [...] deposited at the northward-sloping northern edge of the platform in deeper water, low-energy, mud-bottom environments. Water depths in these environments were estimated by Cressman (1973) to have exceeded 80 ft (24 m), below fair-weather wave base, but within the zone of storm-current reworking."
• "The Point Pleasant Tongue consists of 100 ft of interbedded fossiliferous

•limestone and shale [...] "

Size class: macrofossils

Primary reference: R. C. Frey. 1995. Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati Arch region of Kentucky, Indiana, and Ohio. U.S. Geological Survey Professional Paper 1066P:1-126 [S. Holland/S. Holland]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 87974: authorized by Björn Kröger, entered by Torsten Liebrecht on 29.03.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Cephalopoda
 Orthocerida - Proteoceratidae
"Orthoceras albersi n. sp." = Isorthoceras albersi
"Orthoceras albersi n. sp." = Isorthoceras albersi Miller and Faber 1894
UC 360 (lectotype), 361 (paralectotype)
 Dissidocerida - Geisonoceratidae
"Orthoceras ludlowense n. sp." = Ordogeisonoceras amplicameratum
"Orthoceras ludlowense n. sp." = Ordogeisonoceras amplicameratum Hall 1847
UC 357 (2 individuals), 6457; both specimens are syntypes