USGS M8697 (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; carbonate

• lithology described as a chalk

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 3608: authorized by Mark Patzkowsky, entered by Karen Layou on 05.08.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Cephalopoda
 Ammonitida - Scaphitidae
Trachyscaphites porchi ammonite
Trachyscaphites spiniger porchi
 Ammonitida - Baculitidae
Baculites taylorensis Adkins 1929 ammonite
 Ammonitida - Nostoceratidae
Gastropoda
 Neogastropoda - Turbinellidae
? Napulus sp. Stephenson 1941 snail
originally entered as "Napulus? sp."
Bivalvia
 Arcida - Glycymerididae
? Trigonarca sp. Conrad 1862 clam
originally entered as "?Trigonarca sp."
 Arcida - Cucullaeidae
Cucullaea sp. Lamarck 1801 clam
 Arcida - Arcidae
? Barbatia sp. Gray 1842 clam
originally entered as "?Barbatia sp."
 Myalinida - Inoceramidae
Inoceramus balticus Bohm 1907 clam
 Pectinida - Limidae
 Pectinida - Pectinoidae
cf. Camptonectes bellisculptus scallop
originally entered as "Camptonectes cf. bellisculptus"
Spondylus sp. Linnaeus 1758 scallop
 Pectinida - Neitheoidae
Neithea quinquecostata Sowerby 1814 scallop
 Ostreida - Gryphaeidae
Exogyra erraticostata oyster
Exogyra ponderosa erraticostata
 Ostreida - Pinnidae
cf. Pinna laqueata Conrad 1858 oyster
originally entered as "Pinna cf. laqueata"
 Trigoniida - Megatrigonioidae
Pterotrigonia sp. van Hoepen 1929 clam
 Cardiida - Cardiidae