Where: Antarctica (85.2° S, 166.1° E: paleocoordinates 86.2° S, 155.2° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Meyer Desert Formation (Sirius Group), Middle Miocene (16.0 - 11.6 Ma)

• Based on the occurrence of marine diatoms within the Sirius Group deposits, their age was reported as Pliocene c. 3 Ma (Webb et al. 1994). This age estimate, however, is controversial and likely too young. Several studies suggest that the diatoms were deposited onto older glacial deposits by wind from Pliocene marine deposits located on the margins of the continent (Scherer et al. 2015). Pollen from the Meyer Desert Formation most closely matches an assemblage from near Mount Boreas in the McMurdo Dry Valleys dated by 39Ar/40Ar from a volcanic ash to be of mid-Miocene age (14.07 ± 0.05 Ma., Lewis et al. 2008). Also, fossiliferous Neogene deposits in the region of the Friis Hills in the McMurdo Dry Valleys are early to mid-Miocene based on 39Ar/40Ar dating (Lewis and Ashworth 2016). We conclude that the best age estimate for the trechine fossils is mid-Miocene.

Environment/lithology: fine channel fill; poorly lithified siltstone and fine-grained sandstone

Size class: mesofossils

Preservation: adpression

Reposited in the USNM

• They were disaggregated by soaking in water and wet sieving. The fraction greater than 300 um was examined under a binocular microscope. The fossils are mounted on card slides and are stored in the collections of the Quaternary Entomology Laboratory at North Dakota State University.

Primary reference: R. S. Hill, D. M. Harwood, and P.-N. Webb. 1996. Nothofagus beardmorensis (Nothofagaceae), a new species based on leaves from the Pliocene Sirius Group, Transantarctic Mountains, Antarctica. Review of Palaeobotany and Palynology 94:11-24 [E. Kowalski/E. Kowalski/E. Kowalski]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 137622: authorized by Matthew Clapham, entered by Jered Karr on 18.12.2012, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)