18 m above base, stream bed of Arroyo Las Pulgas, 600 m N of Santiago Ixtaltepec (Carboniferous of Mexico)

Also known as Las Pulgas wash bed, 600 m north of the town of Santiago.

Where: Oaxaca, Mexico (17.6° N, 97.1° W: paleocoordinates 25.8° S, 61.9° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Santiago Formation, Osagean (352.0 - 343.0 Ma)

• 18 meters above formation base.

• formation-level stratigraphic resolution

Environment/lithology: limestone

• gray calcarenite ();

•

•The revised Santiago Formation, as defined herein, is characterized in its lower part by limestone containing tabulate coral banks associated with brachiopods and demosponges belonging to the order Lithistida. These communities are similar to those found in several ‘Osagean’ outcrops in France (D. Vachard, pers. comm.). The reef banks are interbedded with calcareous sandstone nearly 12 m thick that contains the same fossil association. The upper part of the unit is approximately 55 m thick and contains most of the brachiopods described herein.

Size class: macrofossils

Collection methods: FCMP specimens

Primary reference: D. Navarro-Santillan, F. Sour-Tovar, and E. Centeno-Garca. 2002. Lower Mississippian (Osagean) brachiopods from the Santiago Formation, Oaxaca, Mexico: stratigraphic and tectonic implications. Journal of South American Earth Sciences 15(3):327-336 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 67167: authorized by Pete Wagner, entered by Pete Wagner on 11.11.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• The calcarenite has many bryozoans, crinoids, rugose and tabulate corals, gastropods, brachiopods, a few pelecypods, and the rostroconchs reported in this study. Navarro (1997) and Navarro and Sour-Tovar (in press) identified the brachiopods Actinoconchus lamellosus and Torynifer pseudolineatus
Show authors, comments, and common names
Rostroconchia
 Conocardiida - Conocardiidae
Pseudomulceodens cancellatus
Rhynchonellata
 Athyridida - Athyrididae
"Actinoconchus lamellosus" = Athyris lamellosa
"Actinoconchus lamellosus" = Athyris lamellosa Léveillé 1835
5 juvenile forms in different developmental stages, 5 internal molds of pedicle valves (3 fragmented and 2 nearly complete), 1 internal mold of a brachial valve, 1 external impression of a pedicle valve, and 4 external impressions of brachial valves.
 Spiriferinida - Syringothyrididae
Syringothyris sp.
Syringothyris sp.
pedicle valves (7 external molds, 9 internal molds, and1 external impression) and brachial valves (2 external molds and 1 external impression).
 Spiriferinida - Punctospiriferidae
Punctospirifer gigas
Punctospirifer gigas Navarro-Santillan et al. 2002
9 external impressions and 7 internal molds of pedicle valves, 6 external impressions and 3 internal molds of brachial valves, and 1 specimen that shows the posterior part of an internal mold of 1 specimen.
 Spiriferida - Elythidae
Torynifer pseudolineatus
Torynifer pseudolineatus Hall 1858
2 whole specimens with articulated valves; 2 external impressions and 3 internal molds of pedicle valves; 8 internal molds of brachial valves; 11 fragments of internal molds of pedicle valves; and 1 fragment of an external impression.