Gran Bajo de San Julian: Aquitanian, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Spheniscidae
Simpson 1972
Simpson 1946
Simpson 1946
Simpson 1946
Simpson 1946
Reptilia
Simpson 1946
Mammalia - Cetacea
Mammalia - Cetacea - Squalodelphinidae
Mammalia - Cetacea - Kentriodontidae
Ameghino 1901
Cione and Cozzuol 1990
Echinoidea - Clypeasteroida - Scutellidae
Bravard 1858
Rhynchonellata - Terebratulida - Terebratellidae
Bravard 1858
Bivalvia - Pectinida - Pectinidae
Pecten geminatus Sowerby 1846
Bravard 1858
Pecten paranensis d'Orbigny 1842
Bravard 1858
Bivalvia - Ostreida - Ostreidae
Ostrea patagonica d'Orbigny 1842
Bravard 1858
Gastropoda - Turritellidae
Bravard 1858
Gastropoda - Neogastropoda - Nassariidae
Bravard 1858
Gastropoda - Neogastropoda - Muricidae
Fusus patagonicus Sowerby 1846
Bravard 1858
Gastropoda - Ficidae
Bravard 1858
Gastropoda - Struthiolariidae
Struthiolaria ornata Sowerby 1846
Bravard 1858
Gastropoda - Epitoniidae
Bravard 1858
Thecostraca - Balanomorpha - Balanidae
Bravard 1858
see common names

Geography
Country:Argentina
Coordinates: 49.5° South, 68.4° West (view map)
Paleocoordinates:49.0° South, 64.9° West (Wright 2013)
Basis of coordinate:estimated from map
Time
Period: Neogene Epoch: Miocene
Stage: Aquitanian 10 m.y. bin: Cenozoic 5
Key time interval: Aquitanian
Age range of interval: 23.04 - 20.45 m.y. ago
Stratigraphy
Formation:Monte Leon
Stratigraphic resolution:formation
Stratigraphy comments: Age after Parras et al 2008

Parras et al., 2008: No isotopic data are available on the lower part of the Monte León Formation, and the only radiometric 40Ar/39Ar age of 19.33 Ma is from the top of the unit (Fleagle et al., 1995). The 87Sr/86Sr age of 23.83 and 24.12 Ma (latest Oligocene) drawn from top of the San Julián Formation immediately be- low its contact with the overlying Monte León Formation at Cabo Curioso, suggest that the age of the latter at the localities along the coast should lie between 24.12 and 19.33 Ma, i.e., latest Oligo- cene or more probably early Miocene (see Fig. 8).
Lithology and environment
Primary lithology:tuffaceous,gray siltstone
Secondary lithology:tuffaceous,gray sandstone
Includes fossils?Y
Lithology description: light gray tuffaceous siltsones and sandstones
Environment:marginal marine indet.
Taphonomy
Modes of preservation:body,original phosphate
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Metadata
Database number:45887
Authorizer:M. Uhen Enterer:M. Uhen
Modifier:M. Kouvari Research group:marine invertebrate,vertebrate
Created:2004-12-12 08:39:34 Last modified:2025-02-22 15:12:02
Access level:the public Released:2004-12-12 08:39:34
Creative Commons license:CC0
Reference information

Primary reference:
12217. A. L. Cione and M. A. Cozzuol. 1990. Reidentification of Portheus patagonicus Ameghino, 1901, a supposed fish from the Middle Tertiary of Patagonia as a delphinoid cetacean. Journal of Paleontology 64(3):451-453 [M. Uhen/M. Uhen/J. Alroy]

Secondary references:

12218 F. Ameghino. 1901. L' age des Formations sedimentaires de Patagonie. Anales de la Sociedad Cientifica Argentina 52:189-197 [M. Uhen/M. Uhen/M. Uhen]
14629 A. Bravard. 1858. Monografia de los terrenos marinos terciarios, de las cercanias del Parana. Annales Museo Nacional de Buenos Aires 3:45-94 [M. Uhen/M. Uhen/M. Uhen]
25128 G. G. Simpson. 1946. Fossil Penguins. Bulletin of the American Museum of Natural History 87(1):1-100 [M. Uhen/M. Uhen]
25177 G. G. Simpson. 1972. Conspectus of Patagonian fossil penguins. American Museum Novitates 2488:1-37 [M. Uhen/M. Uhen]