Where: Antofagasta, Chile (23.1° S, 70.4° W: paleocoordinates 23.1° S, 70.1° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Sucesion Litoral de Mejillones Formation, Pleistocene (2.6 - 0.0 Ma)

• Pleistocene marine terrace deposits whose formation has been linked with local

•FIGURE 1. Maps showing A, the locality near Mejillones town where the material (SGO.PV.22107a–c) was collected, in Antofagasta Region and B, South America.

•tectonics as well as glacial-interglacial cycling (Cortes et al., 2007). These deposits were first considered as the upper part of the Mejillones Formation (originally assigned to the Pleistocene by Ferraris and di Biase, 1978) and later defined as “Sucesion Litoral de Mejillones” (Cortes, 2000). Recently, Cortes et al. (2007) expanded its age to include the Holocene and divided it into two successions. The first and uppermost succession, consist- ing of marine terraces and littoral beds, is located stratigraphi- cally higher, about 150 m above sea level (m a.s.l.) in the Mejillones Pampa. Fossil invertebrates from this succession include warm water mollusks such as the bivalve Trachycardium procerum and the gastropods Diodora saturnalis and Bulla punc- tulata, which have been assigned to Marine Isotope Stage (MIS) 11, about 400,000 years old (Ortlieb et al., 1996, 1997, 2003). Therefore, the youngest rocks from Mejillones Formation are approximately this age. The second succession comprises marine terraces and littoral belts located below 150 m a.s.l. in the Mejil- lones Pampa exposed east of the town of Mejillones.

•The specimens here studied (SGO.PV.22107a–c) were specifi- cally recovered from the second, lower succession east of the town of Mejillones. The material was included in a coquina asso- ciated with abundant invertebrates, among them the bivalves Diplodonta inconspicua and Ensis macha. The coquina also included isolated bones of large cetaceans (probably mysticetes). The Pleistocene age of this horizon is supported by the presence of the age indicator species Argopecten purpuratus and Concho- lepas concholepas (Herm, 1969; Guzman in Ortlieb, 1995). This lowermost succession also includes recent beach deposits that were likely formed during the last 330 ka, pointing to a middle to upper Pleistocene age for the fossil material here studied (Cortes et al., 2007).

• group of beds-level stratigraphic resolution

Environment/lithology: limestone

Size class: macrofossils

Primary reference: A. M. Valenzuela-Toro, C. S. Gutstein, M. E. Suarez, R. Otero, and N. D. Pyenson. 2015. Elephant seal (Mirounga sp.) from the Pleistocene of the Antofagasta Region, northern Chile. Journal of Vertebrate Paleontology e918883 [M. Uhen/M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 162503: authorized by Mark Uhen, entered by Mark Uhen on 26.09.2014

Creative Commons license: CC BY (attribution)