Tag Archives: paleocene-eocene thermal maximum

Evolution of Earliest Horses Driven by Climate Change

*The hotter it gets, the smaller the animal?*

When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.

It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.

Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)

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Tropical Forest Diversity Increased During Ancient Global Warming Event

The steamiest places on the planet are getting warmer. Conservative estimates suggest that tropical areas can expect temperature increases of 3 degrees Celsius by the end of this century. Does global warming spell doom for rainforests? Maybe not. Carlos Jaramillo, staff scientist at the Smithsonian Tropical Research Institute, and colleagues report in the journal Science that nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.

About the image: This is a scanning electron microscopy image of characteristic angiosperm pollen taxa from the Paleocene-Eocene Thermal Maximum. Image credit: Francy Carvajal, Smithsonian Tropical Research Institute (more…)

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