''Eupachydisus'' is a large, coarse-ribbed Pachydiscid ammonite genus from the Upper Cretaceous, found in
Coniacian
The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by t ...
to
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...
age strata in Europe, Madagascar, Japan, and British Columbia.
The whorl section in ''Eupachydiscus'' is inflated and depressed, almost round in the later growth stages. Ribs are narrow but prominent in the early whorls, becoming thick and strong in the later.
''Eupachydiscus'' is distinct from the mostly later, Campanian -
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...
, compressed and high-whorled ''
Pachydiscus
''Pachydiscus'' is an extinct genus of ammonite from the Late Cretaceous and Early Paleocene with a worldwide distribution, and type for the desmoceratacean family Pachydiscidae. The genus' type species is ''P. neubergicus''. Altogether some 28 s ...
'', but somewhat similar to the coeval, inflated and coarse ribbed, Coniacian-
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...
, ''
Pachydiscoides''
Species
* ''
Eupachydiscus isculensis'' † Redtenbacher 1873
* ''
Eupachydiscus macoveii
''Eupachydisus'' is a large, coarse-ribbed Pachydiscid ammonite genus from the Upper Cretaceous, found in Coniacian to Campanian age strata in Europe, Madagascar, Japan, and British Columbia.
The whorl section in ''Eupachydiscus'' is inflated ...
'' † Szaisz 1981
* ''
Eupachydiscus pseudogrossouvrei'' † Collignon 1955
References
Treatise on Invertebrate Paleontology, Part L, Mollusca 4, R.C. Moore, ed. Geological Soc. of America and Univ. Kansas Press. p L377-L380.
Paleodb-Pachydiscidae5/01/11
Cretaceous ammonites
Ammonites of Europe
Desmoceratoidea
Ammonitida genera
{{Ammonitina-stub