The last mass extinction event some 66 million years ago at the Late Cretaceous/Paleogene
boundary caused the extinction of many clades, including the non-avian dinosaurs.
Turtles, as well as several other vertebrate clades, survived. However, the debate
about whether the diversity of turtles was affected during this event is still ongoing.
Here, I calculate a global turtle diversity curve at the species level that shows
that the diversity of turtle species was already in decline since the Campanian, before
the extinction event, and was further reduced during the Danian. The sample coverage
of turtle occurrences at the stage level is also calculated and discussed.
