Toas Island [Apón Fm] (Cretaceous of Venezuela)

Where: Venezuela (11.0° N, 71.7° W: paleocoordinates 7.7° N, 41.1° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Late/Upper Aptian (122.5 - 112.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Apón Fm, whcih is conformable and gradational with the underlying Río Negro Fm, overlies in other places Triassic-pre-Cambrian beds, overlain by the Aguadiente Fm. AGE: Late Aptian-Middle Albian; placed by enterer in the Late Aptian on the basis of mention of key ammonite horizon dated as such. STRATIGRAPHIC POSITION: From multiple beds in the formation.

• formation-level stratigraphic resolution

Environment/lithology: lithified limestone and lithified, gray, calcareous shale

• ENVIRONMENT: Shallow marine, occasionally deeper as indicated by development of shale.
• SPECIFIC LITHOLOGY: Thick-bedded limestone interbedded with subordinate amounts of dark gray calcareous shale and sandy shale. LITHIFICATION: Lithified, on the basis of facies description.

Size classes: macrofossils, microfossils

Preservation: original calcite

Collected by Dusenbury

Collection methods: surface (in situ),

• COLLECTOR: A. N. Dusenbury (unpublished). REPOSITORY: Not stated in text.

Primary reference: F. A. Sutton. 1946. Geology of Maracaibo Basin, Venezuela: part 1. American Association of Petroleum Geologists Bulletin 30(10):1621-1738 [A. Hendy/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 94208: authorized by Austin Hendy, entered by Austin Hendy on 11.02.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Assumed to be characteristic, but not necessarily exhaustive. NOMENCLATURE: Somewhat antiquated nomenclature, but with some species-resolution assignments.
 Orbitolinacea - Orbitolinidae
Orbitolina concava Lamarck 1816
SUBSPECIES: Orbitolina concava taxana
 Ostreida - Gryphaeidae
"Ostrea (Gryphaeostrea) sp." = Gryphaeostrea, "Exogyra boussingaulti" = Amphidonte (Ceratostreon) boussingaulti
"Ostrea (Gryphaeostrea) sp." = Gryphaeostrea Conrad 1865 oyster
"Exogyra boussingaulti" = Amphidonte (Ceratostreon) boussingaulti d'Orbigny 1842 oyster
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Hippuritida - Caprinuloideidae
Amphitriscoelus waringi Harris and Hodson 1922 rudist
 Hippuritida - Requieniidae
Requienia sp. Matheron 1842 rudist
 Ammonitida - Parahoplitidae
Parahoplites sp. Anthula 1899 ammonite
 Ammonitida - Douvilleiceratidae
Cheloniceras sp. Hyatt 1903 ammonite
 Miliolida - Miliolidae
Quinqueloculina sp. d'Orbigny 1826
 Miliolida - Hauerinidae
Triloculina sp. d'Orbigny 1826