 |
| 3 fossil turtles: Basilemys, Zangerlia and Axestemys are on the left half, the extant turtles Geochelone, Trionyx and Carettochelys on the right half in Chiarenza, Waterson, Schmidt, ... et Barrett, 2022. illustration by Mauricio Anton. |
Highlights:
• Non-marine turtles invaded higher paleolatitudes several times in the past
• Non-marine turtles reached their highest latitudes in the Cenomanian and Eocene
• Occupation of high paleolatitudes is projected at extreme emission scenarios
• Human occupation at high latitudes may prevent turtle adaptation to climate change
Summary
Past responses to environmental change provide vital baseline data for estimating the potential resilience of extant taxa to future change. Here, we investigate the latitudinal range contraction that terrestrial and freshwater turtles (Testudinata) experienced from the Late Cretaceous to the Paleogene (100.5–23.03 mya) in response to major climatic changes. We apply ecological niche modeling (ENM) to reconstruct turtle niches, using ancient and modern distribution data, paleogeographic reconstructions, and the HadCM3L climate model to quantify their range shifts in the Cretaceous and late Eocene. We then use the insights provided by these models to infer their probable ecological responses to future climate scenarios at different representative concentration pathways (RCPs 4.5 and 8.5 for 2100), which project globally increased temperatures and spreading arid biomes at lower to mid-latitudes. We show that turtle ranges are predicted to expand poleward in the Northern Hemisphere, with decreased habitat suitability at lower latitudes, inverting a trend of latitudinal range contraction that has been prevalent since the Eocene. Trionychids and freshwater turtles can more easily track their niches than Testudinidae and other terrestrial groups. However, habitat destruction and fragmentation at higher latitudes will probably reduce the capability of turtles and tortoises to cope with future climate changes.
Keywords: Testudinata, climate change, distribution, Late Cretaceous, Eocene, ecological niche modeling
 |
| 3 fossil turtles: Basilemys, Zangerlia and Axestemys are on the left half, the extant turtles Geochelone, Trionyx and Carettochelys on the right half illustration by Mauricio Anton |
Alfio Alessandro Chiarenza, Amy M. Waterson, Daniela N. Schmidt, Paul J.Valdes, Chris Yesson, Patricia A. Holroyd, Margaret E. Collinson, Alexander Farnsworth, David B. Nicholson, Sara Varela and Paul M. Barrett. 2022. 100 Million Years of Turtle Paleoniche Dynamics enable the Prediction of Latitudinal Range shifts in A Warming World. Current Biology. In Press
