"The varying diameters of the tree stumps coupled with their density within the fossil soil, implies that the forest would have been comprised of trees with interlocking or overlapping branches, thus creating a canopy," Michel said.
Also, further evidence from the excavation site has shown that the landscape was "stable for decades to a few hundred years while the forest grew," Michel added.
Adding to the novelty of the research teams' findings is how all of forest artifacts were contained in one layer or strata.
"What is spectacular about this discovery is that all of these individual elements--tree stumps, leaves, roots, animals--are tied together in a single stratigraphic interval. This gives us tremendous resolution in reconstructing the specific environment inhabited by one of our early ape ancestors," said Kieran P. McNulty, Ph.D., co-director of research on Rusinga Island and associate professor of anthropology at the University of Minnesota.
Researchers were also able to determine the climate for the fossil forest.
"Evidence from the forest fossil soil suggests that the precipitation was seasonal with a distinct wet and dry period. During the dry season, there was probably relatively little rainfall," Peppe said. "Additionally, by studying fossil leaves at the site, we were able to estimate that there was about 55 to 100 inches of rainfall a year and the average annual temperature was between 73 and 94 degrees Fahrenheit."
Research on Rusinga Island has been ongoing for more than 80 years and has resulted in the collection of thousands of mammal fossils, including many well-preserved specimens of Proconsul
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