USGS M8694 (Cretaceous of the United States)

Where: Medina County, Texas (29.3° N, 99.1° W: paleocoordinates 34.9° N, 72.5° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Baculites maclearni ammonoid zone, Anacacho Limestone Formation, Middle Campanian (83.5 - 70.6 Ma)

• Swezey and Sullivan (2004) correlate this bed to the Baculites maclearni zone., which is middle Campanian in Gradstein et al., 2004.

• bed-level stratigraphic resolution

Environment/lithology: marine; limestone

• lithology described as a chalky limestone

Size class: mesofossils

Reposited in the USGS

Primary reference: W. P. Elder. 1996. Bivalves and Gastropods from the Middle Campanian Anacacho Limestone, south central Texas. Journal of Paleontology 70(2):247-271 [M. Patzkowsky/K. Layou/J. Alroy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 3605: authorized by Mark Patzkowsky, entered by Karen Layou on 05.08.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Bivalvia
 Arcida - Parallelodontidae
? Nemodon sp. Conrad 1869 clam
originally entered as "?Nemodon sp."
 Pectinida - Pectinoidae
 Pectinida - Limidae
 Ostreida - Gryphaeidae
Gastropoda
 Neogastropoda - Fasciolariidae
aff. Euthriofusus convexus Wade 1926 snail
originally entered as "Euthriofusus? aff. convexus"
 Neogastropoda - Tudiclidae
? Pyropsis aff. proxima Wade 1926 snail
"n. sp. aff. proxima" - originally entered as "?Pyropsis n. sp. aff. proxima"
Cephalopoda
 Ammonitida - Scaphitidae
Trachyscaphites porchi ammonite
Trachyscaphites polyplocum porchi