Bahia Mazarredo - San Julian Fm: Early Miocene, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Tegulidae
Gastropoda - Trochidae
Gastropoda - Opisthobranchiata
Gastropoda - Naticidae
Gastropoda - Ranellidae
Gastropoda - Ficidae
Ficus carolina (d'Orbigny 1847)
Gastropoda - Struthiolariidae
Gastropoda - Neogastropoda - Volutidae
"Lyria" dalli Ihering 1907
Gastropoda - Neogastropoda - Muricidae
Gastropoda - Neogastropoda - Mangeliidae
Gastropoda - Neogastropoda - Nassariidae
Gastropoda - Turritellidae
Gastropoda - Neotaenioglossa - Trichotropidae
Gastropoda - Epitoniidae
Bivalvia - Carditida - Crassatellidae
Bivalvia - Carditida - Carditidae
Bivalvia - Cardiida - Veneridae
"Chione" eupyga Ihering 1907
"Chione" casa Ihering 1907
"Chione" patagonica (Philippi 1887)
Dosinia meridonalis Ihering 1897
Bivalvia - Pholadida - Corbulidae
unclassified
Bivalvia - Lucinida - Lucinidae
"Lucina" ortmanni Ihering 1899
Bivalvia - Ostreida - Pinnidae
Bivalvia - Ostreida - Ostreidae
Crassostrea hatcheri (Ihering 1899)
Bivalvia - Pectinida - Limidae
Bivalvia - Pectinida - Anomiidae
Bivalvia - Pectinida - Pectinidae
Zygochlamys geminatus (Sowerby 1846)
Jorgechlamys centralis (Sowerby 1846)
Bivalvia - Arcida - Limopsidae
Limopsis insolita (Sowerby 1846)
Bivalvia - Arcida - Cucullaeidae
Bivalvia - Arcida - Parallelodontidae
Cucullaea darwini (Philippi 1887)
Bivalvia - Mytilida - Crenellidae
Bivalvia - Mytilida - Mytilidae
Modiolus ameghinoi (Ihering 1907)
Aulacomya cf. ater (Molina 1782)
Bivalvia - Nuculanida - Malletiidae
Neilo (Neilo) ornata (Sowerby 1846)
see common names

Geography
Country:Argentina
Coordinates: 47.0° South, 66.7° West (view map)
Paleocoordinates:46.5° South, 63.5° West (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:local area
Time
Period: Neogene Epoch: Miocene
10 m.y. bin: Cenozoic 5
Key time interval: Early Miocene
Age range of interval: 23.04 - 15.98 m.y. ago
Stratigraphy
Formation:San Julián
Stratigraphic resolution:group of beds
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From beds of the San Julián Fm, which unconformably overlies the Deseado Fm and is overlain by the Early Miocene Monte Leon Fm. THICKNESS: From multiple beds within formation that reaches a thickness of 80 m. AGE: Late Oligocene-Early Miocene according to molluscan biostratigraphy. Assigned to the Early Miocene based on the the recognition of the JR assemblage. STRATIGRAPHIC POSITION: From uppermost parts of the formation.
Lithology and environment
Primary lithology: poorly lithified sandy "limestone"
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Sandy limestone. LITHIFICATION: Poorly-lithified on the basis of figured specimes.
Environment:coastal indet.
Geology comments: ENVIRONMENT: Environmental data not reported in text. Siliciclastic shallow marine assemblage.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection,survey of museum collection
Reason for describing collection:biostratigraphic analysis
Collection method comments: 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.
Taxonomic list comments:COVERAGE: Exhaustive for bivalvia and gastropoda. NOMENCLATURE: Not an authoritaive publication, but providing revised generic placement for many previously reported antiquated names.
Metadata
Database number:71403
Authorizer:A. Hendy Enterer:A. Hendy
Research group:marine invertebrate
Created:2007-04-24 09:42:55 Last modified:2025-02-22 15:12:02
Access level:authorizer only Released:2007-04-24 09:42:54
Creative Commons license:CC0
Reference information

Primary reference:
12860. 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]