Abstract During the Devonian Nekton Revolution, ammonoids show a progressive coiling of
their shell just like many other pelagic mollusk groups. These now extinct, externally shelled …

Mollusks in general and ammonoids in particular are known to display a sometimes
profound morphological intraspecific variability of their shell. Although this phenomenon is of …

Background A major goal in evolutionary biology is to understand the processes that shape
the evolutionary trajectory of clades. The repeated and similar large-scale morphological …

Raised shell projections on the inner shell walls that form pits on the internal moulds of
Devonian ammonoids have been known for several decades. New specimens from Morocco …

The ammonoids from the well-studied German Fossillagerstätte of the Hunsrück Slate have
the reputation of being the oldest known representatives of this cephalopod group. This …

During its Annual 2007 Meeting in Uzbekistan (BECKER 2009), SDS decided to revise the
base of the Emsian since the current GSSP in the Kitab Reserve lies much lower than …

During and after the Cambrian explosion, very large marine invertebrate species have
evolved in several groups. Gigantism in Carboniferous land invertebrates has been …

Based on revised previous records and many new data from the Tafilalt, Maider, eastern and
western Dra Valley, the Emsian litho-and conodont biostratigraphy of the Anti-Atlas is …

In order to put the origin of the Ammonoidea into the broader evolutionary context, we review
the hypothesis on the origin of cephalopods in general, the origin of bactritids as well as the …

In some Devonian strata in the eastern Anti‐Atlas, fossil invertebrates are abundant, display
a high taxonomic diversity and indicate many shifts in palaeoecology. This is reflected in …