Left bank of Rio Foyel (Miocene of Argentina)

Where: Rio Negro, Argentina (41.7° S, 71.5° W: paleocoordinates 42.6° S, 65.5° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Rio Foyel Formation, Early/Lower Miocene (23.0 - 16.0 Ma)

• According to Bechis et al., 2014: New U-Pb LA-ICPMS geochronology undertaken on detrital zircons gave a maximum age of 21 Ma for the fossil-bearing marine sandstone. In addition, a crystalline tuff intercalated in the middle section of the unit in the nearby Palenque stream gave a U-Pb LA-ICPMS zircon age of 16.6±0.5 Ma. These data represent the first geochronological constraints for these marine beds, which are then comprised between 21 and 16 Ma. Considering the joint presence of the Reticulofenestra haqii and Helicosphaera euphratis in the Rio Foyel, this section can be assigned to NN2-NN4 (Martini, 1971), Early to Middle Miocene, Aquitanian- Langhian.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified, concretionary shale

• "alternate beds of massive shale and concretions with irregular contact surfaces. The shales are up to 5.5 m thick and contain isolated subspherical concretions of different sizes. In some beds they are finely laminated, although the original stratification is probably diagenetically erased. The concetionary beds are up to 5 m thick and yield abundant concretions of different shapes (spherical, ovate and tubular) and sizes (0.5-20 cm diameter).

Size class: macrofossils

Preservation: concretion

Reposited in the CM

Collection methods: surface (float), surface (in situ), mechanical,

• Other repositories are GHUNLPam and MSNM.

Primary reference: S. Casadio, A. De Angeli, R. M. Feldmann, A. Garassino, J. L. Hetler, A. Parras, and C. E. Schweitzer. 2004. New decapod crustaceans (Thalassinidea, Galatheoidea, Brachyura) from the Middle Oligocene of Patagonia, Argentina. Annals of Carnegie Museum 73(2):25-47 [C. Schweitzer/C. Schweitzer/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 45689: authorized by Carrie Schweitzer, entered by Carrie Schweitzer on 24.11.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Anthozoa
 Scleractinia - Flabellidae
Flabellum sp. Lesson 1831 stony coral
Malacostraca
 Decapoda - Ctenochelidae
Callianopsis australis n. sp. Casadio et al. 2004 decapod
 Decapoda - Trichopeltariidae
Trichopeltarion levis n. sp. Casadio et al. 2004 crab
 Decapoda - Macropipidae
Proterocarcinus corsolini n. sp. Casadio et al. 2004 crab
 Decapoda - Tumidocarcinidae
Baricarcinus mariae n. gen. n. sp.
Baricarcinus mariae n. gen. n. sp. Casadio et al. 2004 crab
 Decapoda - Varunidae
Asthenognathus microspinus n. sp. Casadio et al. 2004 crab
 Decapoda - Munididae
Munida casadioi Schweitzer and Feldmann 2000 decapod
Bivalvia
 Nuculanida - Malletiidae
Neilo sp. Adams 1854 clam
 Nuculida - Nuculidae
Nucula sp. Lamarck 1799 nut clam
 Mytilida - Mytilidae
Brachidontes sp. Swainson 1840 mussel
 Ostreida - Pinnidae
Atrina sp. Gray 1842 oyster
 Pectinida - Pectinoidae
Zygochlamys sp. Ihering 1907 scallop
 Arcida - Cucullaeidae
Cucullaea sp. Lamarck 1801 clam
 Hiatellida - Hiatellidae
Panopea nucleus Ihering 1899 clam
 Cardiida - Veneridae
Dosinia sp. Scopoli 1777 venus clam
Gastropoda
 Neogastropoda - Fasciolariidae
Fusinus sp. Rafinesque 1815 snail
 Cerithioidea - Turritellidae
Turritella sp. Lamarck 1799 turret shell
Echinoidea
 Spatangoida - Schizasteridae
? Schizaster sp. Agassiz 1835 heart urchin
 Ichnofossils -
Thalassinoides sp. Ehrenberg 1944