El Chacay Fm - El Bajo, Provincia de Santa Cruz: Burdigalian, Argentina
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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unclassified
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Valdesia (Juliana) schucherti
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Echinoidea
- Spatangoida
- Schizasteridae
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Brisaster sp.
Gray 1855
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Rhynchonellata
- Terebratulida
- Terebratellidae
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Terebratella informal sp. A
d'Orbigny 1847
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Terebratella informal sp. B
d'Orbigny 1847
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Terebratella patagonica
(Sowerby 1846)
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Gmelinmagas plicata
Marinelarena 1964
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Gastropoda
- Heterostropha
- Acteonidae
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Acteon bajoensis
Chiesa et al. 1995
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Gastropoda
- Turritellidae
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Turritella ambulacrum
Sowerby 1846
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| Subspecies: T. ambulacrum argentina | ||||||||||
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Gastropoda
- Neotaenioglossa
- Calyptraeidae
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Crepidula sp.
Lamarck 1799
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Gastropoda
- Naticidae
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Polinices chiloensis
(Philippi 1887)
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| recombined as Neverita chiloensis | ||||||||||
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Gastropoda
- Neogastropoda
- Buccinidae
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Pseudofax solitaria
Chiesa et al. 1995
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Gastropoda
- Neogastropoda
- Volutidae
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Proscaphella cossmanni
Ihering 1907
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Gastropoda
- Neogastropoda
- Muricidae
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Purpura chicoana
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Gastropoda
- Struthiolariidae
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Struthiolarella ornata
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Bivalvia
- Nuculanida
- Nuculanidae
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Nuculana sp.
Link 1807
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Bivalvia
- Nuculida
- Nuculidae
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Nucula (Leionucula) patagonica
(Philippi 1887)
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Bivalvia
- Pectinida
- Pectinidae
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Zygochlamys jorgensis
(Ihering 1907)
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Bivalvia
- Ostreida
- Ostreidae
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Crassostrea hatcheri
(Ihering 1899)
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Bivalvia
- Cardiida
- Lahillidae
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Lahillia patagonica
(Ihering 1907)
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Bivalvia
- Lucinida
- Lucinidae
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Lucina neglecta
Ortmann 1902
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Bivalvia
- Carditida
- Carditidae
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Venericardia sp.
Lamarck 1801
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Demospongiae
- Spirosclerophorida
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Ortmannia ortmanni
Chiesa et al. 1995
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| see common names | ||||||||||
Geography
| Country: | Argentina |
| Coordinates: | 48.8° South, 70.8° West (view map) |
| Paleocoordinates: | 49.6° South, 65.0° West |
| Basis of coordinate: | estimated from map |
| Geographic resolution: | outcrop |
Time
| Period: | Neogene | Epoch: | Miocene |
| Stage: | Burdigalian | 10 m.y. bin: | Cenozoic 5 |
| Key time interval: | Burdigalian | ||
| Age range of interval: | 20.44000 - 15.98000 m.y. ago |
Stratigraphy
| Formation: | El Chacay | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: STRATIGRAPHIC RELATIONS: From El Chacay Fm, which regionally overlies Basalto Posadas and is overlain by the Santa Cruz Fm (Eocene-Oligocene). THICKNESS: AGE: Eocene. No further detail provided. Justified on the basis of stratigraphic position and biostratigraphic correlation. This unit has more recently been dated as early Miocene (Burdigalian) by Sr isotopes (Cuitiño et al., 2015) and correlative units also as Burdigalian by U-Pb chronology (Cuitiño et al., 2012). STRATIGRAPHIC POSITION: Unknown stratigraphic position within section. Figure 3 (Chiesa et al. 1995) suggests that the collection is derived from multiple distinct beds within the formation at each section. | |||||
Lithology and environment
| Primary lithology: | lithified sandstone |
| Secondary lithology: | shelly/skeletal lithified sandy "mixed carbonate-siliciclastic" |
| Includes fossils? | Y |
| Includes fossils? | Y |
| Lithology description: SPECIFIC LITHOLOGY: No specific lithology stated though Figure 3 (Chiesa et al. 1995) suggests that macrofauna are typically derived from sandstones and sandy coquinas at each section. LITHIFICATION: Lithified, based on figured specimens. | |
| Environment: | marine indet. |
| Geology comments: ENVIRONMENT: Shallow marine arenaceous platform, normal salinity, under a subtropical climate, with water temperatures between 19-22 degrees C. | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | poor |
| Articulated whole bodies: | some |
Collection methods and comments
| Collection methods: | selective quarrying,field collection |
| Reason for describing collection: | biostratigraphic analysis |
| Collection method comments: COLLECTORS: Presumably collected by authors during broader lithostratigraphic study and geologic mapping (see Chiesa and Camacho, 1995). REPOSITORY: CIRGEO (Centro de Investigaciones en Recursos Geologicos), Argentina. | |
| Taxonomic list comments:COVERAGE: Exhaustive for all macrofaunal groups (Brachiopoda, Bivalvia, Gastropoda). NOMENCLATURE: Authoritative paper using subgeneric and species-level designations. | |
Metadata
| Database number: | 65186 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy |
| Modifier: | M. Clapham | Research group: | marine invertebrate |
| Created: | 2006-09-19 15:25:40 | Last modified: | 2017-07-30 18:59:23 |
| Access level: | group members | Released: | 2007-03-19 15:25:40 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 18786. | J.O. Chiesa, S.G. Parma, and H.H. Camacho. 1995. Observaciones estratigraficas en el Paleogeno del noroeste de la Provincia de Santa Cruz (Republica Argentina). Parte II: Invertebrados marinos de la Formacion El Chacy (Eoceno), Provincia de Santa Cruz, Argentina. Systematica y bioestratigrafia. Monografias de la Acadamia Nacional de Ciencias Exactas, Fisicas Y Naturales 11:17-68 [A. Hendy/A. Hendy] |