Expanded sedimentary records from the Tethys reveal unique :faunal and
isotopic changes across the Palaeocene-Eocene (P-E) transition. Unlike
in the open oceans, the Tethys exhibits a gradual decrease of 1.5 parts
per thousand in delta(13)C values prior to the rapid delta(13)C
excursion. Associated with the delta(13)C excursion is a decrease in
calcite burial, increase in detrital content and appearance of a unique
opportunistic planktic foraminiferal assemblage (e.g. compressed
acarininids). The existence of a prelude decrease in delta(13)C values
in the Tethys suggests that the P-E delta(13)C excursion may have
occurred in two steps and over a few hundred thousand years, rather than
as one step over a few thousand years as previously suggested. This
slower excursion rate is readily explained by changing organic carbon
weathering or burial rates and avoids the need of invoking ad hoc
scenarios.