Where: Argentina (45.7° S, 67.4° W: paleocoordinates 46.3° S, 61.8° W)

• coordinate estimated from map

When: Gaiman Formation, Burdigalian (20.4 - 16.0 Ma)

• Patagonian Marine Formation (Gaiman or Monte León formations)

•

•The Patagonian Marine Formation corresponds to the partially correlated Monte León and Gaiman formations, exposed in Santa Cruz (e.g. Garn Bajo de San Juan) and the lower Chubut river valley near Trelew (e.g. at Bryn Gwyn/ Loma Blanca), respectively [42]. The Gaiman Formation consists of layers of marine sandstones and mudstones, as well as tuffs and tuffaceous sandstones. In addition, the lower part also contains occasional thin layers of Ostrea and bones of marine vertebrates [43]. Thus, the portion of the Gaiman Formation exposed near Trelew provides a likely match for the unit that yielded A. moreni [39, 40, 44].

•11

•In the area around Trelew, the lower part of Gaiman Formation overlies the continental Sarmiento Formation, which contains a mammal fauna correlating with the Colhuehuapian South American Land Mammal Age [43, 45]. The latter has been 40Ar/39Ar dated to 20.9– 19.8 Ma [46], thus providing a maximum age of 19.8 Ma (earliest Burdigalian) for the lower part of the Gaiman Formation in this area. Since virtually all vertebrate material recovered so far originated from the lowermost levels of the Gaiman Formation, close to its contact with the Sarmiento Formation [Cozzuol 2010, pers. comm.], an early Burdigalian age (19.8–18.2 Ma) is here assumed for A. moreni. (Marx & Fordyce, 2015)

• formation-level stratigraphic resolution

Environment/lithology: shoreface; lithology not reported

Size class: macrofossils

Collection methods: Collected by J. B. Abbott and George Sternberg, members of E. S. Riggs' party from the Field Museum of Natural History.

Primary reference: R. Kellogg. 1934. The Patagonian Fossil Whalebone Whale, Cetotherium moreni (Lydekker). Carnegie Institution of Washington 447:64-81 [M. Uhen/M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 87889: authorized by Mark Uhen, entered by Mark Uhen on 27.03.2009

Creative Commons license: CC BY (attribution)