Open AccessThe ammonoids from the Three Forks Shale (Late Devonian) of Montana
Author(s) -
Korn Dieter,
Titus Alan
Publication year - 2006
Publication title -
fossil record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.694
H-Index - 19
eISSN - 1860-1014
pISSN - 1435-1943
DOI - 10.1002/mmng.200600008
Subject(s) - devonian , paleontology , ammonoidea , geology , oil shale , fauna , late devonian extinction , taxon , biology , ecology , carboniferous , mesozoic , structural basin
The ammonoid fauna from the Late Devonian Three Forks Shale of Montana is revised. Six taxa were recognised, which belong to the genera Tornoceras , Pernoceras , Raymondiceras , Platyclymenia , Pleuroclymenia , and Carinoclymenia . The ammonoid assemblage suggests a stratigraphic position within the middle Famennian, most probably the Platyclymenia annulata Zone. The ammonoids display extreme septal crowding in intermediate as well as adult growth stages, which can be regarded as evidence for instable palaeoecological conditions during lifetime of the animals. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)