February 7, 2007
STUDY
SHOWS LARGEST
The
largest climate change in central
The overwhelming
majority of
previous climate-change studies on the 400,000-year transition from the
Eocene
to the Oligocene epochs, about 33.5 million years ago, focus on marine
environments, but
The study will be published online Feb. 7 in the journal Nature and will appear in the Feb. 8 print edition.
"If a temperature
change of
this magnitude occurred today,
The Eocene-to-Oligocene transition is known in the fossil record as the Grande Coupure, the "Big Cut" in French, because it marks a massive extinction of life in both marine and land environments. Scientists believe the drop in temperature was likely due to changes in oceanic currents, MacFadden said.
"Fossil mammals are archives of ancient information," MacFadden said. "Their teeth are like little time capsules that allow us to analyze chemicals captured millions of years ago within the animals' skeletons."
MacFadden said 49 of
the 68
fossil teeth analyzed came from the
"A combined analysis
of the
isotope composition of bones and teeth is a new approach to studying
this
boundary in time," said Alessandro Zanazzi, a doctoral student in
geology
at the
Donald R. Prothero, a professor of geology at Occidental College and an expert on the Eocene-to-Oligocene transition, said, "We have long known that there were some dramatic climatic changes in the earliest Oligocene based on the record of marine plankton and isotopes. But we didn't know how much change there was in degrees, although the plant changes suggested it was indeed about 15 degrees."
Prothero also said
gaps in the
fossil record from
##
Contact:
Bruce
MacFadden
University
of
Florida
352-262-3072
bmacfadd@flmnh.ufl.edu
This
text derived from:
http://news.ufl.edu/