south side of the Quebrada La Pola, Eastern flank of Sierra de Villicum: Caradoc, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Pterobranchia - Graptoloidea - Dicranograptidae
Bivalvia - Nuculanida - Malletiidae
4 specimens
Spec. #s: CEGH-UNC 16714a (holotype), 16153d, 17361d, 16780b (2 measurements)
Bivalvia - Nuculida - Praenuculidae
Praenucula sp. Pfab 1934
1 specimen
Spec. #: CEGH-UNC 16170b (1 measurement)
13 specimens
Spec. #s: CEGH-UNC 16158 (holotype), 16153b, 16153c, 16159, 16160, 16161a, 16162, 16163, 16167b, 16172d, 16715b, 16756b, 16715b (6 measurements)
9 specimens
Spec. #s: CEGH-UNC 16152a (holotype), 16153a, 16154, 16155a, 16156, 16157, 16172c, 16772b, 17361b (6 measurements)
9 specimens
Spec. #s: CEGH-UNC 16719 (holotype), 16155b, 16720, 16721, 16756c, 17357, 17358, 17362b, 17364 (5 measurements)
7 specimens
Spec. #'s: CEGH-UNC 16168 (holotype), 16166, 16169, 17351, 17352, 17353, 17356 [entered as Cocavodonta ovalis] (4 measurements)
9 specimens
Spec. #: CEGH-UNC 16164a, 16161b, 16165, 16170a, 16756d, 16767b, 17354, 17355, 17361c (7 measurements)
1 specimen
Spec. #: CEGH-UNC 16172b (1 measurement)
6 specimens
Spec. #s: CEGH-UNC 16171 (holotype), 16152b, 16172a, 16714b, 16777b, 17363 (5 measurements)
Bivalvia - Actinodontida - Cycloconchidae
4 specimens
Spec. #s: CEGH-UNC 16718, 16716, 16717, 17350
Sánchez et al. 2003
Rhynchonellata - Orthida - Draboviidae
? Drabovia sp. Havlicek 1950
Rhynchonellata - Orthida - Dalmanellidae
Rhynchonellata - Orthida - Hesperorthidae
Hesperorthis sp. Schuchert and Cooper 1931
Rhynchonellata - Orthida - Plaesiomyidae
Dinorthis sp. Hall and Clarke 1892
Strophomenata - Strophomenida - Leptellinidae
Strophomenata - Strophomenida - Aegiromenidae
see common names

Geography
Country:Argentina State/province:San Juan
Coordinates: 31.3° South, 68.5° West (view map)
Paleocoordinates:31.6° South, 170.2° East (Wright 2013)
Geographic resolution:outcrop
Time
Period: Ordovician Epoch: Late Ordovician
10 m.y. bin: Ordovician 4-5
*Period:Late/Upper Ordovician
*International age/stage:Early/Lower Caradocian
Key time interval: Caradoc Graptolite zone:  Climacograptus bicornis
Age range of interval: 458.2 - 449.5 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:La Cantera Member:Upper
Stratigraphic resolution:formation
Stratigraphy comments: Villas (1995) notes that the clasts containing fossils probably originated from the underlying La Cantera formation. The upper half is Climacograptus bicornis zone, the lower half is Hustedograptus teretiusculus zone.
Lithology and environment
Primary lithology:pebbly conglomerate
Lithology description: Fossils described come from the upper part of the lower member of the Don Braulio Fm. The lower member (8-12 m) is composed of pebbly mudstones capped by channelized conglomerates. This succession is interpretted as a diamictite. Studied fossils have come from coquinites in the diamictite.
Environment:marine indet.
Geology comments: "Fossils described in this paper come from pebbles of the upper part of the lower diamictite member of the Don Braulio Fm. Clasts consist of sandstones, limestones, quatzites, quartz, and volcanic rocks, some of them being striated and facetted. This succession is interpretted as glacimarine in origin and is synchronous with the Late Ashgillian world-wide glaciation event."
Taphonomy
Modes of preservation:body,cast
Degree of concentration:concentrated
Size of fossils:macrofossils,mesofossils
Spatial orientation:random
Preservation of anatomical detail:good
Fragmentation:frequent
Temporal resolution:time-averaged
Collection methods and comments
Collection excludes:some genera,some macrofossils,some microfossils
Collection methods:chemical,field collection
Reason for describing collection:taxonomic analysis
Collection method comments: "In order to enhance exposure of teeth and muscle scars, shells were dissolved with hydrochloric acid (10%).
Metadata
Database number:13513
Authorizer:A. Miller, P. Wagner Enterer:R. Krause, P. Wagner
Modifier:P. Wagner Research group:marine invertebrate
Created:2002-04-10 12:21:02 Last modified:2025-02-22 15:12:02
Access level:the public Released:2002-04-10 12:21:02
Creative Commons license:CC0
Reference information

Primary reference:
6121. T. M. Sanchez. 1999. New late Ordovician (Early Caradoc) Bivalves from the Sierra De Villicum (Argentine Precordillera). Journal of Paleontology 73(1):66-76 [A. Miller/R. Krause/P. Wagner]

Secondary references:

86266 T. M. Sánchez, L. Marengo, and R. A. Astini. 2003. Late Ordovician Bivalvia Heteroconchia (Cycloconchidae and Glyptarcidae) from western Argentina. Ameghiniana 40(3):433-440 [P. Wagner/P. Wagner]