Lonco Vaca (Cretaceous of Argentina)

Where: Argentina (37.9° S, 70.0° W: paleocoordinates 36.9° S, 33.1° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Lower Agrio Member (Agrio Formation), Late/Upper Valanginian (140.2 - 136.4 Ma)

• fossils are from unit 2 m below massive, 4 m thick siltstone, which is taken by some authors to mark the base of the Agrio Formation

• bed-level stratigraphic resolution

Environment/lithology: marine; gray siltstone and shelly/skeletal, gray, sandy packstone

• fossils in a thinm grey, sandy coquina below a massive grey siltstone

Size class: macrofossils

Primary reference: M. B. Aguirre-Urreta and P. F. Rawson. 1999. Lower Cretaceous ammonites from the Neuquen Basin, Argentina: Viluceras, a new Valanginian subgenus of Olcostephanus. Cretaceous Research 20:343-357 [J. Alroy/E. Leckey/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 37787: authorized by John Alroy, entered by Erin Leckey on 23.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

 Ammonitida - Olcostephanidae
Olcostephanus (Viluceras) sp. Aguirre-Urreta and Rawson 1999 ammonite