Isla Grande de Tierra del Fuego (Early Oligocene) (Oligocene of Argentina)

Where: Argentina (50.2° S, 72.9° W: paleocoordinates 52.1° S, 63.9° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Early/Lower Oligocene (33.9 - 28.4 Ma)

• STRATIGRAPHIC RELATIONS: Lithostratigraphy not stated. AGE: Paleontological evidence suggests an Eocene to Early Oligocene age for this fauna. Strong faunal similarity to San Julian (Eocene-Oligocene), Monte Leon (Oligocene) and Loreto Formations (Oligocene-Miocene). Several taxa also recorded in the Millongue and Boqueron Formations of Chile. An Oligocene age is assigned here on the basis of commonality in age between correlated formations. STRATIGRAPHIC POSITION: Composite collection from unit within local area.

• formation-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, shelly/skeletal, conglomeratic sandstone

• ENVIRONMENT: No environmental data reported in text. Faunal composition suggests an inner shelf siliciclastic environment, though not very shallow.
• SPECIFIC LITHOLOGY: Conglomeratic sandstone containing many skeletal elements. LITHIFICATION: Poorly lithified on the basis of figured specimens (gastropods with sediment filled apertures, sediment adhearing to external surfaces),

Size class: macrofossils

Preservation: original aragonite, original calcite

Collection methods: quarrying,

• COLLECTOR: M. Doello-Jurado, N. Malumian and H. H. Camacho, possibly R. Gorrono, plus existing collections in the Museo Argentino de Ciencias Naturales and Servico Geologico Nacional. REPOSITORY: Museo Argentino de Ciencias Naturales and Servico Geologico Nacional.

Primary reference: N. Malumian, H. H. Camacho, and R. Gorrono. 1978. Molluscos del Terciario Inferior ("Magallanense") de la Isla Grande de Tierra del Fuego (Republica Argentina). Ameghiniana 15(3-4):265-284 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 66146: authorized by Austin Hendy, entered by Austin Hendy on 02.10.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for bivalvia and gastropoda. Corals, brachiopods, foraminifera and palynomorhs apparently also present. NOMENCLATURE: Authoritative publication that appears to use fairly modern nomenclature, and subgeneric and species-level resolution.
unclassified
  -
Anthozoa
 Scleractinia - Flabellidae
Flabellum cf. cuneiforme Lonsdale 1845 stony coral
Subspecies: F. cf. cuneiforme wailesi
Gastropoda
 Neotaenioglossa - Calyptraeidae
Calyptraea sp. Lamarck 1799 slipper shell
 Cerithioidea - Turritellidae
Turritella ambulacrum Sowerby 1846 turret shell
Subspecies: T. ambulacrum sylva
 Sorbeoconcha - Aporrhaidae
 Sorbeoconcha - Struthiolariidae
Struthiolarella densestriata Ihering 1897 snail
 Neogastropoda - Buccinidae
"Nassa" fueguina Steinmann and Wilckens 1908 true whelk
Austrocominella fueguensis Ihering 1907 true whelk
 Neogastropoda - Muricidae
Trophon sp. Montfort 1810 murex snail
 Neogastropoda - Volutidae
Miomelon becki, "Miomelon cf. gracilior" = Miomelon gracilis
Miomelon becki volute
Subspecies: M. becki cannada
"Miomelon cf. gracilior" = Miomelon gracilis Philippi 1887 volute
 Sorbeoconcha - Naticidae
"Polinices (Euspira) santacruzensis" = Euspira, "Polinices (Euspira) sp." = Euspira
"Polinices (Euspira) santacruzensis" = Euspira moon snail
"Polinices (Euspira) sp." = Euspira Agassiz 1837 moon snail
 Heterostropha - Acteonidae
""Actaeon" chilensis" = Acteon
""Actaeon" chilensis" = Acteon snail
Bivalvia
 Arcida - Cucullaeidae
Cucullaea (Cucullona) alta Sowerby 1846 clam
 Arcida - Glycymerididae
 Mytilida - Mytilidae
Modiolus ameghinoi Ihering 1907 mussel
 Lucinida - Lucinidae
"Miltha promaucana" = Lucinoma promaucana
"Miltha promaucana" = Lucinoma promaucana Philippi 1877 clam
Subspecies: M. promaucana crucialis
 Cardiida - Veneridae
Eurhomalea cf. fuenzalidai Philippi 1887 venus clam
 Carditida - Carditidae
Cardiocardita inaequalis Philippi 1887 clam
Pleuromeris elegantoides Ortman 1902 clam
 Nuculida - Nuculidae
Nucula (Leionucula) grandis n. sp. Malumian et al. 1978 nut clam