Transition zone between San Juan and Gualcamayo or Los Azules formations, Guanda (Ordovician of Argentina)

Where: Argentina (30.0° S, 69.0° W: paleocoordinates 36.9° S, 130.2° W)

• local area-level geographic resolution

When: Arenig (478.6 - 466.0 Ma)

• Transition zone between San Juan and Gualcamayo or Los Azules formations

• group of beds-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified, argillaceous limestone

• dark and marly limestone

Collection methods: JA: marked by Novack-Gottshall without explanation as omitting some genera, some macrofossils, some microfossils, and species names, but apparently complete

Primary reference: J. L. Benedetto, F. Canas, and R. Astini. 1986. Braquiopodos y trilobites de la zona de transicion entre las Formaiones San Juan y Gualcamayo en el area de Guandacol (La Rioja, Argentina). Actas del IV congreso Argentino de paleontologia y bioestratigrafia - Simposio: Bioestratigrafia del Paleozoico Inferior. Ed. A. Cuerda 1:103-111 [A. Miller/P. Novack-Gottshall]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 8872: authorized by Arnold Miller, entered by Phil Novack-Gottshall on 02.09.2000

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Trilobita
 Asaphida - Asaphidae
Opsimasaphus sp.
Opsimasaphus sp. Kielan 1960 trilobite
 Asaphida - Nileidae
Nileus sp.
Nileus sp. Dalman 1827 trilobite
 Trinucleida - Raphiophoridae
Ampyx sp.
Ampyx sp. Dalman 1827 trilobite
 Ptychopariida - Shumardiidae
Shumardia sp.
Shumardia sp. Billings 1862 trilobite
 Olenida - Olenidae
Bienvillia sp.
Bienvillia sp. Clark 1924 trilobite
 Phacopida - Cheiruridae
Parapilekia sp.
Parapilekia sp. Kobayashi 1934 trilobite
 Proetida - Telephinidae
Carolinites sp.
Carolinites sp. Kobayashi 1940 trilobite
Artiopoda
 Agnostida - Agnostidae
? Micragnostus sp.
? Micragnostus sp. Howell 1935
Rhynchonellata
 Orthida - Plectorthidae
Nanorthis sp.
Nanorthis sp. Ulrich and Cooper 1936