Also known as Residual concretions of calcareous sandstone in a field just south of Chatfield, Navarro County; from upper part of formation.

Where: Navarro County, Texas (32.1° N, 96.5° W: paleocoordinates 36.9° N, 68.8° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Nostoceras hyatti ammonoid zone, Nacatoch Sand Formation, Late/Upper Campanian (83.5 - 70.6 Ma)

• Stephenson (1941) had this unit as Maastrichtian, Cobban and Kennedy (1995) have updated it to uppermost Campanian via ammonite zonation.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; concretionary, calcareous sandstone

Size class: mesofossils

Reposited in the USGS

• L. W. Stephenson 1911

Primary reference: L. W. Stephenson. 1941. The larger invertebrate fossils of the Navarro group of Texas. The University of Texas Publication 4101:1-625 [M. Kosnik/M. Kosnik]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 7500: authorized by Matt Kosnik, entered by Matt Kosnik on 18.07.2000

Creative Commons license: CC BY (attribution)