Around 66 million years ago, a massive extinction event wiped out many species, including the dinosaurs. However, some animals, like turtles, managed to survive. Scientists have been debating whether this extinction event affected the variety of turtle species. This study creates a detailed curve showing the number of turtle species over time. It was found that the variety of turtles was already decreasing before the extinction event and continued to drop afterward. This suggests that the extinction event had a significant impact on turtle diversity, which had already been in decline.

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.