Sylvain Richoz
Universitetslektor
Middle Triassic conodont assemblages from the Germanic Basin: implications for multi-element taxonomy and biogeography
Författare
Summary, in English
Conodonts have been a key tool for biostratigraphical, evolutionary and palaeobiogeographical studies, and the Germanic
Basin has been one of the most important regions for these studies. However, few modern studies provide systematic data on
the mainly endemic conodonts of the Middle Triassic Germanic Basin. Here we document conodonts from two sections in
Germany, one Bithynian in age and the other late Anisian to early Ladinian in age. The two sections captured two episodes
of marine fauna invasion in the Germanic epicontinental basin during the Middle Triassic. The conodont Neogondolella
mombergensis, elsewhere reported as appearing globally, is reviewed and revised, confirming previous suggestions that this
species only occurs in the Germanic Basin. Apparatuses of Neogondolella haslachensis and Nicoraella germanica from the
Germanic Basin are proposed. It was generally expected that S and M elements within clades have a very high morphological
stability compared to P elements. However, the apparatus of Nicoraella germanica differs significantly from that of south
China, indicating that the morphology of S elements within a genus can be unstable, and thus promotes our understanding of
conodont evolution. The rarely documented genus Gondolatus, which was suggested as representing pathological specimens,
is confirmed as a valid genus in the Germanic Basin. Our data suggest that endemic conodonts evolved twice, not only in the
Upper Muschelkalk Subgroup, but also in the Lower Muschelkalk Subgroup.
Basin has been one of the most important regions for these studies. However, few modern studies provide systematic data on
the mainly endemic conodonts of the Middle Triassic Germanic Basin. Here we document conodonts from two sections in
Germany, one Bithynian in age and the other late Anisian to early Ladinian in age. The two sections captured two episodes
of marine fauna invasion in the Germanic epicontinental basin during the Middle Triassic. The conodont Neogondolella
mombergensis, elsewhere reported as appearing globally, is reviewed and revised, confirming previous suggestions that this
species only occurs in the Germanic Basin. Apparatuses of Neogondolella haslachensis and Nicoraella germanica from the
Germanic Basin are proposed. It was generally expected that S and M elements within clades have a very high morphological
stability compared to P elements. However, the apparatus of Nicoraella germanica differs significantly from that of south
China, indicating that the morphology of S elements within a genus can be unstable, and thus promotes our understanding of
conodont evolution. The rarely documented genus Gondolatus, which was suggested as representing pathological specimens,
is confirmed as a valid genus in the Germanic Basin. Our data suggest that endemic conodonts evolved twice, not only in the
Upper Muschelkalk Subgroup, but also in the Lower Muschelkalk Subgroup.
Avdelning/ar
- Berggrundsgeologi
Publiceringsår
2018-01-25
Språk
Engelska
Sidor
1-19
Publikation/Tidskrift/Serie
Journal of Systematic Palaeontology
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Taylor & Francis
Ämne
- Geology
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1477-2019