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… 
Divergent mammalian body size in a stable Eocene greenhouse climate
The results support the view that intrinsic biotic processes are an important driver of body mass outside of abrupt climate events and generate one of the most extensive mammalian Paleogene body size datasets outside North America.
Northward range extension of a diminutive-sized mammal (Ectocion parvus) and the implication of body size change during the Paleocene-Eocene Thermal Maximum
Abstract An abrupt global warming event marks the Paleocene–Eocene boundary, known as the Paleocene–Eocene Thermal Maximum (PETM). The event is distinguished in the strata globally by a significant
Accelerated body size evolution during cold climatic periods in the Cenozoic
It is shown that global temperatures fluctuations through the Cenozoic impacted body size evolution, and the evolution of body size was faster during periods of global cooling in most of the groups, challenging the hypothesis that evolution is faster under warm climates.
Paleohydrologic response to continental warming during the Paleocene–Eocene Thermal Maximum, Bighorn Basin, Wyoming
Abstract Geologically rapid global warming occurred during the Paleocene–Eocene Thermal Maximum (PETM) ~ 56 Ma. Several studies have argued that important changes occurred in the hydrological cycle
Evaluating the responses of three closely related small mammal lineages to climate change across the Paleocene–Eocene thermal maximum
Abstract. Interpreting the impact of climate change on vertebrates in the fossil record can be complicated by the effects of potential biotic drivers on morphological patterns observed in taxa. One
Mammal faunal change in the zone of the Paleogene hyperthermals ETM2 and H2
Abstract. "Hyperthermals" are past intervals of geologically rapid global warming that provide the opportunity to study the effects of climate change on existing faunas over thousands of years. A
Widespread rapid reductions in body size of adult salamanders in response to climate change.
Compared historic and contemporary size measurements in 15 Plethodon species from 102 populations and found that six species exhibited significant reductions in body size over 55 years, consistent with a plastic response of body size to climate change through reductions inBody size as mediated through increased metabolism.
The evolution of mammal body sizes: responses to Cenozoic climate change in North American mammals
This model argues that the body sizes of Nearctic mammals were moulded by Cenozoic climate and vegetation changes, and reemphasizes the necessity of considering the evolutionary history and resultant form and function of mammalian morphotypes when attempting to understand contemporary mammalian body size distributions.
Carbon isotope stratigraphy and mammal turnover during post-PETM hyperthermals
Abstract. Paleogene hyperthermals, including the Paleocene-Eocene Thermal Maximum (PETM) and several other smaller events, represent global perturbations to Earth's climate system and are
Mammal Community Structure through the Paleocene-Eocene Thermal Maximum
It is suggested that invasion by new taxa had little impact on Paleocene-Eocene mammal communities because niches were not saturated, consistent with numerous studies of modern communities that record little change in community-scale richness despite turnover in taxonomic composition during invasion.


Continental warming preceding the Palaeocene–Eocene thermal maximum
It is shown that continental warming of about 5 °C preceded the CIE in the Bighorn Basin, Wyoming and the results suggest that at least two sources of warming—the earlier of which is unlikely to have been methane—contributed to the PETM.
A humid climate state during the Palaeocene/Eocene thermal maximum
The authors' results provide evidence for a previously unrecognized discrete shift in the state of the climate system during the PETM, characterized by large increases in mid-latitude tropospheric humidity and enhanced cycling of carbon through terrestrial ecosystems.
Environment and evolution through the Paleocene-Eocene thermal maximum.
  • P. Gingerich
  • Geology, Medicine
    Trends in ecology & evolution
  • 2006
Global environmental events such as the PETM have had profound effects on evolution in the geological past and must be considered when modeling the history of life and when considering the causes and consequences of global greenhouse warming.
The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future
During the Paleocene-Eocene Thermal Maximum (PETM), ∼56 Mya, thousands of petagrams of carbon were released into the ocean-atmosphere system with attendant changes in the carbon cycle, climate, ocean
A tale of two species: Extirpation and range expansion during the late Quaternary in an extreme environment
Abstract Death Valley, California is today the hottest hyperarid area in the western Hemisphere with temperatures of 57 °C (134 °F) recorded. During the late Quaternary, pluvial Lake Manly covered
Transient Floral Change and Rapid Global Warming at the Paleocene-Eocene Boundary
Floral response to warming and/or increased atmospheric CO2 during the PETM was comparable in rate and magnitude to that seen in postglacial floras and to the predicted effects of anthropogenic carbon release and climate change on future vegetation.
Magnitude of the carbon isotope excursion at the Paleocene-Eocene thermal maximum: The role of plant community change
Carbon-isotope measurements (δ 13 C) of leaf-wax n-alkanes from the Paleocene–Eocene Thermal Maximum (PETM) in the Bighorn Basin, Wyoming, reveal a negative carbon isotope excursion (CIE) of 4–5‰,
Transient drying during the Paleocene–Eocene Thermal Maximum (PETM): Analysis of paleosols in the bighorn basin, Wyoming
Abstract The Paleocene Eocene Thermal Maximum (PETM) was a transient episode of global warming that occurred at the Paleocene/Eocene boundary. The event is marked by a sharp decline in carbon isotope
Correlation between isotope records in marine and continental carbon reservoirs near the Palaeocene/Eocene boundary
CHANGES in the isotope content of the large marine carbon reservoir can force shifts in that of the smaller carbon pools in the atmosphere and on land. The carbon isotope compositions of marine
New stratigraphic and paleontological information from the McCullough Peaks, northern Bighorn Basin, Wyoming, is incorporated into an isotaphonomic faunal database and used to investigate the impact