whale bone bipedalism
March 19, 2015

Whale skull reveals birthplace of humanity in East Africa

Chuck Bednar for redOrbit.com - @BednarChuck

An ancient whale skull is revealing new information about the birthplace of humanity and the role that climate change played in human evolution, researchers from the University of Potsdam in Germany and colleagues from Kenya and the US report in a new study.

kenya whale bone

A map of Africa and Kenya showing where a 17-million-year-old whale fossil was found far inland . (Credit: Wichura/PNAS)

The fossil, which according to UPI reports was lost for nearly four decades, belonged to a beaked whale and was found 460 miles inland in Kenya in 1964. The location of the skull indicated that it must have gotten lost and swam up a freshwater river system, but since it was first identified as a turtle skull, scientists did little analysis on it before it wound up being put to the side.

Jim Mead whale bone

Jim Mead, an undergraduate student at Yale University, discovered the fossil in 1964 while on a field expedition with a team from Harvard. (Credit: Harvard)

Birthplace of bipedalism

For nearly 40 years, the skull remained in the Harvard University archives before Louis Jacobs, a paleontologist at Southern Methodist University in Dallas, found the fossil after a lengthy search. By conducting a detailed analysis of the skull, Jacobs and his colleagues found that it contained a number of important clues that helped them determine precisely when and where bipedalism first emerged in humans, the news organization added.

“The whale is telling us all kinds of things,” Jacobs, one author of a new Proceedings of the National Academy of Sciences study published Monday, told the Los Angeles Times. “It tells us the starting point for all that uplift that changed the climate that led to humans. It's amazing.”

[STORY: Fossil jaw pushes human origins back 400,000 years]

According to Discovery News, the whale lived at a time when the East African plateau was covered by dense forests and would have significantly lower than it is today. At the time when this uplift first took place, trees and vegetation in the region would no longer have been able to receive moisture from the Indian Ocean, likely causing the area to become a grassland.

A whale of a fossil

The now-extinct ancestors of modern humans would have lived in trees in East Africa, the researchers explained. Once the area turned into a savannah, however, those early pre-humans would have gradually started learning how to walk on two feet. The whale fossil helps narrow down when all of this would have taken place, the study authors indicated, placing the events sometime between 17 million and 13.5 million years ago.

The skull is said to be the oldest known fossil of a beaked whale, but due to the confusion over the type of creature it originated from, it took 11 years for scientists to publish the first study on it, the website explained. After that, it was misplaced until 2011 until it was rediscovered in the Harvard archives, in the former office of renowned paleontologist Stephen Jay Gould.

[STORY: Fossil skull reveals human emigration out of Africa]

After it was found, University of Potsdam postdoctoral candidate Henry Wichura, Jacobs, and their colleagues used it to help date the uplift of the East African plateau. Taking the grade of the steepest river from case reports and applying it to the prehistoric river used by the whale, the study authors determined that if the river rose at 2.5 inches a mile from the coast, the plateau would have been 79 feet and 121 feet high at the time of the whale’s death.

Currently, the plateau is more than 2,000 feet tall, indicating that the northern part of the Eastern African plateau must have been uplifted by roughly 1,925 feet over the last 17 million years, the authors of the new study determined. They also concluded that the uplift had already begun as of 13.5 million years ago – something they would not have learned without that skull.

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