Where: La Pampa, Argentina (37.4° S, 67.6° W: paleocoordinates 39.5° S, 59.0° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Vaca Mahuida Formation, Late/Upper Eocene (37.2 - 33.9 Ma)

• Upper Vaca Mahuida Fm, corresponds to UM4

•

•Discovery of an anseriform presbiornitid bird (Tambussi et al., 1996). together with the occurrence of mammals referred to the Friasan South American "Land Mammal Age" (Franchi et al., 1984) in the Vaca Mahuida Formation, suggest a Paleogene-middle Miocene age bracket for this stratigraphic unit. However, the frog-bearing horizon lies below strata that yielded remains of a Paleogene notoungulate (Montalvo and Bond, in press), as well as below those containing a presbionitid bird; thus, this constrains the anuran age to the late Paleocene-middle Eocene range.

Environment/lithology: lacustrine - large; green mudstone and volcaniclastic

Size class: macrofossils

Primary reference: R. Melchor, S. Casadio, and G. Visconti. 1992. Analisis estratigrafico secuencial de los depositos lacustres Eocenos de la Formacion Vaca Mahuida, SO de la provincia de La Pampa, Argentina. Cuarta Reunion Argentina de Sedimentologia 1:151-158 [J. Alroy/J. Wertheim/J. Wertheim]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 47318: authorized by John Alroy, entered by Jill Wertheim on 22.02.2005

Creative Commons license: CC BY (attribution)