Turtle biodiversity losses suggest coming sixth mass extinction

Abstract

Biodiversity losses in the face of climate change are among the most important issues facing humanity today. Vertebrate extinction is at an all-time high, and losses of reptiles are no exception. The turtles are a unique vertebrate group of grave conservation concern. I compared recent declines in turtle biodiversity to the losses of Testudinata (Cryptodira + Pleurodira) and non-dinosaurian reptiles during the most recent mass extinction. Fuzzy arithmetic was used because of its suitability to deal with uncertainty in these kinds of data sets and the questions that arise with comparing geological data with those from recent times. This revealed that extinctions of turtles in modern times massively exceed losses observed at the Cretaceous–Paleogene border. Further, if turtle extinctions continued at their current level, massive losses of these charismatic animals could occur within our lifetime and loss of the entire group could occur in just a few centuries. We must ask ourselves, how much more can we lose before we also disappear.