Upper Atanekerdluk (Paleocene of Greenland)

Where: Greenland (70.1° N, 52.2° W: paleocoordinates 62.3° N, 22.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Naujat Member (Atanikerluk Formation), Selandian (61.6 - 59.2 Ma)

• Koch identified the Upper Atanikerdluk A flora and the Upper Atanikerdluk B flora of Heer (1883a, b) in the basal part of the formation (lowermost Naujât Member). A maximum age for the Atanikerluk Formation is obtained from the NP4 – possibly early NP5 marine dinocysts in the underlying Eqalulik Formation (Nøhr-Hansen et al. 2002). Samples from the volcanic Ordlingassoq and Rinks Dal Members give radiometric ages of 60.7–61.1 ± 0.5–1.0 Ma, recalculated from Storey et al. (1998). This indicates an early to mid-Paleocene (possibly Selandian) age for the Atanikerluk Formation.

Environment/lithology: lacustrine; lithified, black, gray mudstone

• The mudstones are interpreted as lacustrine deposits on the basis of the high C/S ratios, the absence of pyrite, the presence of terrestrial fossils (macrofossil plants, spores and pollen) and the general absence of marine dinocysts.

•As a result of the opening of the Labrador Sea in Late Mesozoic to Early Cenozoic times, a complex of linked rift basins stretching from the Labrador Sea to northern Baffin Bay developed along West Greenland. Two main episodes of regional rifting and basin development during this time have been documented in the area: an episode of Early Cretaceous rifting, and a Late Cretaceous – Early Paleocene rift episode prior to the start of sea-floor spreading in mid-Paleocene time.

• The Naujât Member comprises dark grey to black mudstones with thin, discontinuous layers of sandstones and thin tuff beds.

Size class: macrofossils

Preservation: mold/impression

Collected by Steenstrup

• Specimens probably in the Mineralogical Museum, Copenhagen (Steenstrup collection)

Primary reference: O. Heer. 1883. Ueber die fossilen Insekten Grönlands. Flora Fossilis Grönlandica. Die Fossile Flora Grönlands 143-148 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 124000: authorized by Matthew Clapham, entered by Matthew Clapham on 05.02.2012, edited by Jered Karr

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Insecta
 Coleoptera - Trogossitidae
Tenebroides insignis n. sp.
Tenebroides insignis n. sp. Heer 1868 bark gnawing beetle
 Trichoptera - Phryganeidae
Phryganea hyperborea n. sp.
Phryganea hyperborea n. sp. Heer 1883 large caddisfly
 Orthoptera - Tettigoniidae
"Locusta groenlandica n. sp." = Arctolocusta groenlandica
"Locusta groenlandica n. sp." = Arctolocusta groenlandica Heer 1883 katydid
Chrysomelites lindhageni
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Chrysomelites lindhageni