Okay Quarry [Phosphate bed, Annona Fm] (Cretaceous of the United States)

Where: Howard County, Arkansas (33.8° N, 93.9° W: paleocoordinates 37.9° N, 65.7° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Annona Formation (Taylor Group), Late/Upper Campanian (83.5 - 70.6 Ma)

• STRATIGRAPHIC RELATIONS: From the Annona Fm, which regionally overlies the Ozan Fm, and is overlain by the Marlbrook Fm, all of the Taylor Gp. AGE: Late Campanian on the basis of ammonite biostratigraphy; Baculites gregoryensis/B. reduncus zone. STRATIGRAPHIC POSITION: From phosphate bed at very base of Annona Fm.

• bed-level stratigraphic resolution

Environment/lithology: lithified, concretionary, phosphatic, black, brown, yellow, conglomeratic lime mudstone

• ENVIRONMENT: Shallow marine cabonate setting.
• SPECIFIC LITHOLOGY: Grey weathering chalky marl, with phosphatic nodules, sometimes welded into a phosphatic conglomerate. The phosphates are black, pale brown, and cream coloured. LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression, original calcite

Collected by Kennedy et al. in 1973-1974; reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: W.J. Kennedy, W.A. Cobban, R.E. Burkholder, and B.F. Clardy, 1974-1974. REPOSITORY: USNM, Washington DC.

Primary reference: W. J. Kennedy and W. A. Cobban. 1993. Upper Campanian ammonites from the Ozan-Annona Formation boundary in Southwestern Arkansas. Bulletin of the Geological Society of Denmark 40:115-148 [A. Hendy/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 83054: authorized by Austin Hendy, entered by Austin Hendy on 06.08.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for ammonoids, and including informally listed bivalves and gastropods. NOMENCLATURE: An authoritative publication, with modern nomenclature and species-resolution identifications.
unclassified
  -
Avellanidae indet.
LISTED as "avellanid"
Bivalvia
 Pectinida - Dimyidae
Atreta sp. Etallon 1862 scallop
 Pectinida - Pectinoidae
Spondylus sp. Linnaeus 1758 scallop
 Ostreida - Gryphaeidae
Pycnodonte sp. Fischer von Waldheim 1835 oyster
 Myalinida - Inoceramidae
Inoceramus sp. Sowerby 1814 clam
Cephalopoda
 Nautilida - Nautilidae
Eutrephoceras sp. Hyatt 1894 nautiloid
 Ammonitida - Scaphitidae
 Ammonitida - Diplomoceratidae
Oxybeloceras crassum Whitfield 1877 ammonite
 Ammonitida - Baculitidae
Baculites sp. Lamarck 1799 ammonite
Baculites taylorensis Adkins 1929 ammonite
 Ammonitida - Nostoceratidae
Didymoceras sp. Hyatt 1900 ammonite
"Nostoceras (Nostoceras) platycostatum" = Didymoceras platycostatum Kennedy and Cobban 1993 ammonite
 Ammonitida - Tetragonitidae
Pseudophyllites sp. Kossmat 1895 ammonite
 Ammonitida - Pachydiscidae
Pachydiscus (Pachydiscus) sp. Zittel 1884 ammonite
Menuites cf. portlocki Sharp 1855 ammonite
 Ammonitida - Desmoceratidae
Desmophyllites diphylloides Forbes 1846 ammonite
 Ammonitida - Placenticeratidae
Placenticeras sp. Meek 1876 ammonite
Gastropoda
 Trochoidea - Trochidae
Trochidae indet. Rafinesque 1815 top snail
LISTED as "trochid"
 Pleurotomarioidea - Pleurotomariidae
Pleurotomariidae indet. Swainson 1840 snail
LISTED as "pleurotomariid"