Menat (Des Forest collection) (Paleocene of France)

Where: Auvergne, France (46.1° N, 2.9° E: paleocoordinates 40.3° N, 0.7° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Menat Formation, Selandian (61.6 - 59.2 Ma)

• The estimated age of the Menat site varies. It was previously dated by pollen analysis, mammal stratigraphy, and an unpublished radiometric K/Ar analysis as late Paleocene (see Kedves & Russell 1982). However, several lines of more recent evidence indicate an older, middle Paleocene (Selandian) age, of about 60-61 Ma. Paleomagnetic studies reveal that the eruption took place during a reversed interval (Kedves & Russell 1982). Fossils of the mammal Plesiadapis from Menat enable the locality to be connected to the biostratigraphic framework established in the Western Interior USA that relies extensively on this genus (Gingerich 1976; Secord et al. 2006). The abundance of the genus, its rapid evolution, and its Holarctic dispersal history allow species of Plesiadapis to play an important role in the zonation of Paleocene continental sediments and in correlation of faunas on both sides of the North Atlantic (e.g., Gingerich 1976). Two remarkable skeletons of P. insignis, one of them nearly complete, have been found in lake deposits at Menat, and this species closely compares to P. praecursor / P. anceps in North America (pers. comm. P. Gingerich August 2008). This suggests an early Selandian age, equivalent to the early Tiffanian Ti-1/Ti-2 land mammal biozonation sensu Secord et al. (2006) (see also Gingerich 1976; Russell 1967, 1975). In North America, the Ti1 and Ti2 biozones occur within magnetic polarity Chron 26r (Secord et al. 2006), consistent with the reversed polarity of the Menat sediments.

Environment/lithology: crater lake; diatomite

• Volcanic Paleolake (maar) deposit
• spongo-diatomitic

Size classes: macrofossils, mesofossils

Preservation: mold/impression

Collected by Des Forest; reposited in the MNHN

Primary reference: L. Piton and N. Théobald. 1937. Les lignites et schistes bitumineux de Menat (Puy-de-Dôme). II: Les insectes fossiles de Menat. Revue des Sciences Naturelles d'Auvergne 3(2):76-88 [M. Clapham/M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 120352: authorized by Matthew Clapham, entered by Jered Karr on 10.11.2011, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)

Taxonomic list

Insecta
 Blattodea - Blattidae
Eoplaneta desforesti n. gen. n. sp.
Eoplaneta desforesti n. gen. n. sp. Piton and Théobald 1937 cockroach
Coll. Des Forest 2
 Hemiptera - Pentatomidae
Pentatomidae indet. Leach 1815 stink bug
Coll. Des Forest 10
 Coleoptera - Tenebrionidae
Ancylochira oligostriata n. sp. Piton and Théobald 1937 darkling beetle
Coll. Des Forest 3