title: Evolution of the earliest horses driven by climate change in the Paleocene-Eocene Thermal Maximum.
abstract: Body size plays a critical role in mammalian ecology and physiology. Previous research has shown that many mammals became smaller during the Paleocene-Eocene Thermal Maximum (PETM), but the timing and magnitude of that change relative to climate change have been unclear. A high-resolution record of continental climate and equid body size change shows a directional size decrease of ~30% over the first ~130,000 years of the PETM, followed by a ~76% increase in the recovery phase of the PETM. These size changes are negatively correlated with temperature inferred from oxygen isotopes in mammal teeth and were probably driven by shifts in temperature and possibly high atmospheric CO(2) concentrations. These findings could be important for understanding mammalian evolutionary responses to future global warming.
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, NE 68588, USA. rsecord2@unl.edu
authors.forename: Ross
authors.initials: R
authors.lastname: Secord
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Bloch
authors.forename: Stephen G B
authors.initials: SG
authors.lastname: Chester
authors.forename: Doug M
authors.initials: DM
authors.lastname: Boyer
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Wood
authors.forename: Scott L
authors.initials: SL
authors.lastname: Wing
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Kraus
authors.forename: Francesca A
authors.initials: FA
authors.lastname: McInerney
authors.forename: John
authors.initials: J
authors.lastname: Krigbaum
mesh_terms: D000818:Animals; D001272:Atmosphere; D005075:Biological Evolution; D049628:Body Size; D002245:Carbon Dioxide / Q000032:analysis; D057231:Climate Change; D018397:Equidae / Q000033:anatomy & histology*; D005580:Fossils; D057232:Global Warming; D006736:Horses / Q000033:anatomy & histology*; D006813:Humidity; D010103:Oxygen Isotopes / Q000032:analysis; D013696:Temperature; D014959:Wyoming
chemical_list: D010103:Oxygen Isotopes; D002245:Carbon Dioxide