The Anisian depositional history in the Western Tethys realm provides the possibility to study the stepwise opening of the
Neo-Tethys, and is well preserved in the sedimentary record of the Northern Calcareous Alps. Whereas the depositional
characteristic in the Early (to early Middle) Anisian is characterized by shallow-water carbonates, formed in a semi-restricted
environment, the situation changed in the Middle Anisian. A rapid increase of subsidence resulted in an abrupt deepening
event with deposition of deeper-water limestones, in some cases even with chert nodules, sometimes with resedimented
shallow-water debris intercalated in radiolaria-filament wackestones, or with clayey or marly intercalations. This abrupt
deepening, termed the Annaberg Event, is followed by a shallow-water carbonate evolution. The deeper-water limestones
can be dated by conodonts and shallow-water organisms like calcareous algae or foraminifera from the resedimented intercalations
as Late Bithynian to Early Pelsonian. In contrast to the Early Anisian microbial carbonates, formed under semirestricted
conditions, the Middle Anisian (Pelsonian) shallow-water carbonates were formed under fully marine influence
and a diverse fauna and flora was, therefore, able to counterbalance the rapid subsidence by increasing carbonate production.
During Middle Anisian times, the newly tectonically created accommodation space became rapidly filled by shallow-water
carbonates. At the end of the Middle Anisian (Late Pelsonian), the final break-up of the Neo-Tethys led to a rapid decrease
of carbonate production and widespread deposition of deep-marine and condensed limestones. This drowning event (Reifling
Event) was accompanied by the formation of a horst-and-graben morphology, dated by conodonts and ammonoids as
late Middle Anisian from overlying condensed limestones. In contrast to the well-known drowning event in the late Middle
Anisian, precursor events to the final oceanic break-up of the Neo-Tethys have not yet been described, but play an important
role in the reconstruction of the opening history of the Neo-Tethys. This kn