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Climate-mediated diversification of turtles in the Cretaceous (free pdf)



Ben Creisler
bcreisler@gmail.com

A new paper in open access:

David B. Nicholson, Patricia A. Holroyd, Roger B. J. Benson & Paul M.
Barrett (2015)
Climate-mediated diversification of turtles in the Cretaceous.
Nature Communications 6, Article number: 7848
doi:10.1038/ncomms8848
http://www.nature.com/ncomms/2015/150803/ncomms8848/full/ncomms8848.html


Chelonians are ectothermic, with an extensive fossil record preserved
in diverse palaeoenvironmental settings: consequently, they represent
excellent models for investigating organismal response to long-term
environmental change. We present the first Mesozoic chelonian taxic
richness curve, subsampled to remove geological/collection biases, and
demonstrate that their palaeolatitudinal distributions were climate
mediated. At the Jurassic/Cretaceous transition, marine taxa exhibit
minimal diversity change, whereas non-marine diversity increases. A
Late Cretaceous peak in ‘global’ non-marine subsampled richness
coincides with high palaeolatitude occurrences and the Cretaceous
thermal maximum (CTM): however, this peak also records increased
geographic sampling and is not recovered in continental-scale
diversity patterns. Nevertheless, a model-detrended richness series
(insensitive to geographic sampling) also recovers a Late Cretaceous
peak, suggesting genuine geographic range expansion among non-marine
turtles during the CTM. Increased Late Cretaceous diversity derives
from intensive North American sampling, but subsampling indicates that
Early Cretaceous European/Asian diversity may have exceeded that of
Late Cretaceous North America.