'Entomis' migrans Community, Ludlow, Armorican Massif (Silurian of France)

Where: France (47.5° N, 0.7° W: paleocoordinates 58.9° S, 44.7° E)

• coordinate based on political unit

• local area-level geographic resolution

When: Ludlow (427.4 - 423.0 Ma)

Environment/lithology: marine; black lime mudstone

• General statement of Central Armorican trough during Llandovery through Lochkovian: "depositional patterns typical of a platform environment...Silurian is mainly an alternating succession of unfossiliferous sandstones and locally fossiliferous black shales...The arenaceous deposits are probably related to the eustatic regression and corresponding high sedimentation rate during the Pridolian and Lochkovian...Outside the A. Massif the Pridoli-Lochkovian succesion in Artois (boreholes) is characterized by shallow marine shales and limestones overlain by areanceous deposits that correspond to the Early Devonian transgression."

•For this Community: "Benthic fauna is always very rare. In the Prague Basin this unit represents the deepest facies; a smilar position is provisionally accepted here."

• General statement: "In Brittany there are two kinds of black shale and limestone deposits during the Llandovery to lowermost Devonian interval: (1) black shales (commonly described as sapropelites) are widespread in space and time and (2) black, micritic limestones or argillaceous limestones are restricted to two localities in the eastern part of the Armorican Massif. The black shales are very rich in organic matter and locally contain detrital mica, pyrite, and nodules..."

•For this community: "At La Meignanne this community occurs in black, micritic limestone."

Primary reference: P. R. Racheboeuf. 1999. Lower Silurian to Lower Devonian communities from the Armorican Massif (western France) and Artois (northern France). In A. J. Boucot, J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 260-270 [M. Foote/M. Foote/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26110: authorized by Michael Foote, entered by Michael Foote on 04.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Cyrtodontida - Slavidae
""Hemicardium" elevatum" = Slavinka elevata
""Hemicardium" elevatum" = Slavinka elevata Barrande 1881 clam
 Cyrtodontida - Cardiolidae
Cardiolidae indet. Hoernes 1884 clam
Polychaeta
  -
Plumulites sp. Barrande 1872 scale worm
Ostracoda
 Cypridinida - Bolbozoidae
""Entomis" migrans" = Entomozoe
""Entomis" migrans" = Entomozoe ostracod