Cape Wiman (Institute of Polar Studies location 1) (Eocene of Antarctica)

Where: Antarctica (64.2° S, 56.6° W: paleocoordinates 63.7° S, 61.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: La Meseta Formation, Lutetian (47.8 - 41.3 Ma)

• Location places it within Telm1. The age model for the La Meseta Formation (and recently-defined Submeseta Formation) is controversial. Strontium isotopes (Ivany et al., 2008) suggest earlier ages, with the La Meseta (Telm1-Telm5) almost entirely Ypresian and the Submeseta (Telm6-Telm7) Middle-Late Eocene. Montes et al. (2013) also created an age model incorporating magnetostratigraphy to support the largely-Ypresian age for the La Meseta and Middle-Late Eocene for the Submeseta. Some mammals are similar to the radiometrically-constrained late early Eocene Paso del Sapo assemblage of Patagonia (Gelfo et al., 2009, Tejedor et al., 2009), but the mammals are not exactly similar (Bond et al., 2011). However, Douglas et al. (2014) re-evaluated the strontium data and used dinoflagellate biostratigraphy to argue for a Lutetian (Telm2-4) and younger (Bartonian to mid-Priabonian for Telm5-6) age range. Amenábar et al. (2019) also found younger ages from dinoflagellates: Lutetian (Telm1-mid Telm 3), Bartonian (mid Telm 3-mid Telm 5), and Priabonian (upper Telm 5), SPDZ10-SPDZ13. This age range is more consistent with the presence of basilosaurid whales in Telm4 and Telm7, as basilosaurids are globally-distributed first in the middle Eocene (Buono et al., 2016). Although the ages are still debated, the dinoflagellate age model of Amenábar et al. (2019) is used here.

• bed-level stratigraphic resolution

Environment/lithology: prodelta; siliciclastic sediments

• According to Stilwell & Zinsmeister (1992), “As shallow seas invaded, by subsidence or rise in sea level, a normal shelf marine community developed during the middle Eocene to form the fossil accumulations of Telm1. The shell-bearing facies of Telm1 appear to have accumulated in low areas on an erosional surface that was flooded during the transgression. Parallel to current-ripple laminations indicate that some minor wave or current activity was associated with the transgressive event.” Combination of current ripples with overall fine-grained setting, and the presence of slumps in overlying Telm2, consistent with a prodelta environment.

Size class: macrofossils

Preservation: cast

Collection methods: Repository: probably Ohio State University

Primary reference: W. J. Zinsmeister. 1978. Eocene nautiloid fauna from the La Meseta Formation of Seymour Island, Antarctic Peninsula. Antarctic Journal of the United States 13(4):24-25 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 180150: authorized by Matthew Clapham, entered by Matthew Clapham on 09.07.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Cephalopoda
 Nautilida - Nautilidae
"Eutrephoceras argentinae" = Euciphoceras argentinae
"Eutrephoceras argentinae" = Euciphoceras argentinae Del Valle and Fourcade 1976