L-OB-LC - upper Monte Leon Fm (Miocene of Argentina)

Where: Argentina (50.2° S, 68.9° W: paleocoordinates 51.0° S, 62.3° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Monte Leon Fm Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• STRATIGRAPHIC RELATIONS: From upper beds of the Monte Leon Fm. THICKNESS: From multiple beds within part of formation of less than 60 m. AGE: Early Miocene according to molluscan biostratigraphy. Assigned to the Early Miocene based on the the recognition of the upper PA assemblage. STRATIGRAPHIC POSITION: From uppermost part of the formation.

• group of beds-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified sandstone

• ENVIRONMENT: Environmental data not reported in text. Siliciclastic shallow marine assemblage.
• SPECIFIC LITHOLOGY: Sandstone. LITHIFICATION: Poorly-lithified on the basis of figured specimens.

Size class: macrofossils

Collection methods: COLLECTOR: List includes both new collections by the author, and examination of museum and previously reported taxa. REPOSITORY: Museo Argentino de Ciencias Naturales Bernadino Rivadavia, Buenos Aires, Argentina.

Primary reference: C. J. del Rio. 2004. Tertiary Marine Molluscan Assemblages of Eastern Patagonia (Argentina): A Biostratigraphic Analysis. Journal of Paleontology 78(6):1097-1122 [L. Ivany/P. Wall/P. Wall]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 71539: authorized by Austin Hendy, entered by Austin Hendy on 28.04.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for bivalvia and gastropoda. NOMENCLATURE: Not an authoritaive publication, but providing revised generic placement for many previously reported antiquated names.
unclassified
  -
Bivalvia
 Nuculanida - Nuculanidae
Pseudoportlandia glabra pointed nut clam
 Nuculida - Nuculidae
"Lamellinucula lunulae" = Nucula (Lamellinucula)
"Lamellinucula lunulae" = Nucula (Lamellinucula) nut clam
 Mytilida - Mytilidae
Modiolus ameghinoi Ihering 1907 mussel
 Ostreida - Ostreidae
Crassostrea hatcheri Ihering 1899 oyster
 Ostreida - Malleidae
"Perna quadrisulcata" = Isognomon quadrisulcata
"Perna quadrisulcata" = Isognomon quadrisulcata Ihering 1897 oyster
 Pectinida - Pectinoidae
"Swiftopecten iheringi" = Chlamys (Swiftopecten)
"Swiftopecten iheringi" = Chlamys (Swiftopecten) scallop
 Arcida - Limopsidae
Limopsis insolita Sowerby 1846 clam
 Arcida - Glycymerididae
 Arcida - Cucullaeidae
 Arcida - Arcidae
"Arca patagonica" = Arca (Arca) patagonica
"Arca patagonica" = Arca (Arca) patagonica Ihering 1897 ark
 Carditida - Carditidae
Pleuromeris sp. Conrad 1867 clam
 Cardiida - Cardiidae
""Cardium" puelchum" = Trachycardium puelchum Sowerby 1846 cockle
Hedecardium philippi Ihering 1897 cockle
 Cardiida - Tellinidae
"? Tellinella patagonica" = Tellina (Tellinella) tellin clam
 Cardiida - Mactridae
 Cardiida - Veneridae
Ameghinomya argentina Ihering 1897 venus clam
Austrocallista iheringi Cossmann 1898 venus clam
 Pholadida - Pholadidae
Pholadidea patagonica Philippi 1887 clam
 Lucinida - Lucinidae
Gastropoda
 Heterostropha - Acteonidae
"Actaeon semilaevis" = Acteon
"Actaeon semilaevis" = Acteon snail
 Heterostropha - Pyramidellidae
 Neotaenioglossa - Calyptraeidae
Crepidula gregaria slipper shell
"Calyptraea" pileus Lamarck 1822 slipper shell
 Sorbeoconcha - Struthiolariidae
Struthiolarella cuevensis Camacho and Zinsmeister 1989 snail
Struthiolarella ameghinoi Ihering 1897 snail
 Neogastropoda - Muricidae
"Urosalpinx" archipatagonica Ihering 1907 murex snail
Trophon santacrucensis Ihering 1897 murex snail
Xymene dautzembergi murex snail
 Neogastropoda - Volutidae
Pachycymbiola ameghinoi Ihering 1896 volute
 Neogastropoda - Cancellariidae
 Neogastropoda - Terebridae
 Neogastropoda - Mitridae
Austroimbricaria quemadensis Ihering 1897 mitre shell
 Sorbeoconcha - Naticidae
""Polynices" sanatacrucensis" = Polinices, ""Polynices" secunda" = Polinices, "Polynices" consimilis
""Polynices" sanatacrucensis" = Polinices moon snail
""Polynices" secunda" = Polinices moon snail
"Polynices" consimilis Ihering 1907 moon snail
 Epitonioidea - Epitoniidae
 Cerithioidea - Turritellidae
"Turritella" ambulacrum Sowerby 1846 turret shell
 Trochoidea - Trochidae