Basal Shales, La Venta Fm., Aragoncillo (Ordovician of Spain)

Also known as Basal Shales, La Venta Fm., Aragoncillo, Guadalajara, Spain

Where: Guadalajara, Spain (40.9° N, 2.1° W: paleocoordinates 71.0° S, 89.7° E)

• coordinate estimated from map

• local area-level geographic resolution

When: Corymbograptus retroflexus graptolite zone, Lower Member (Villar del Salz Formation), Oretanian (466.0 - 460.9 Ma)

• Basal Shales of the formation. PJW: Herranz Araújo et al (2003; 2004) designated informal and poorly diagnosed & defined La Venta the Villar del Salz formation. These are the beds beneath the Didymograptus artus zone, which should be the Corymbograptus retroflexus zone. Overlies Armorican Quartzite. Underlies San Marcos.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified shale

• Dark shales

Size class: macrofossils

Preservation: mold/impression

Primary reference: C. Babin and J. C. Gutiérrez-Marco. 1991. Middle Ordovician bivalves from Spain and their phyletic and palaeogeographic significance. Palaeontology 34:109-147 [A. Miller/P. Novack-Gottshall/P. Novack-Gottshall]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 20914: authorized by Arnold Miller, entered by Phil Novack-Gottshall on 12.06.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• Bivalve taxonomy
Trilobita
 Corynexochida -
Illaenoidea indet. Hawle and Corda 1847 trilobite
 Phacopida - Calymenidae
Neseuretus "sp. nov." Hicks 1873 trilobite
Salterocoryphe sampelayoi trilobite
Hammann
 Asaphida - Asaphidae
Megistaspis sp. Jaanusson 1956 trilobite
Asaphellus cf. cianus trilobite
(Verneuil and Barrande
 Asaphida - Nileidae
Nileidae indet. Angelin 1854 trilobite
Rhynchonellata
 Orthida - Ranorthidae
Ranorthis sp. Öpik 1939
Rostroconchia
 Ribeirioida - Technophoridae
Bivalvia
 Arcida - Glyptarcidae
Hemiprionodonta lusitanica Sharpe 1853 clam
(Sharpe)
 Modiomorphida - Modiomorphidae
 Protobranchia - Ctenodontidae
"Ctendonta cf. escosurae" = Ctenodonta
"Ctendonta cf. escosurae" = Ctenodonta clam
 Nuculida - Praenuculidae
Praenucula costae Sharpe 1853 clam
(Sharpe
 Nuculida -
Ekaterodonta hesperica n. sp. Babin and Gutiérrez-Marco 1991 clam
Gastropoda
 Bellerophontida - Sinuitidae
Sinuites sp. Koken 1896 snail
Graptolithina
 Diplograptoidea - Diplograptidae
Expansograptus sp. Bouček and Přibyl 1953 diplograptoid