Evolution of the Earliest Horses Driven by Climate Change in the Paleocene-Eocene Thermal Maximum

  title={Evolution of the Earliest Horses Driven by Climate Change in the Paleocene-Eocene Thermal Maximum},
  author={Ross Secord and Jonathan I. Bloch and Stephen G. B. Chester and Doug M. Boyer and Aaron R. Wood and Scott L. Wing and Mary J. Kraus and Francesca A. McInerney and John Krigbaum},
  pages={959 - 962}
Warming and Shrinking In most mammals, individual body sizes tend to be smaller in warmer regions and larger in cooler regions. Secord et al. (p. 959; see the Perspective by Smith) examined a high-resolution 175,000-year record of equid fossils deposited over a past climate shift—the Paleocene-Eocene Thermal Maximum—for changes in body size. Using oxygen isotopes collected from the teeth of co-occurring mammal species to track prevailing environmental temperature, a clear decrease in equid body… 

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