Fossilized Fish Bones in the Sahara Desert Show How Diets Changed With the Climate
by Theresa Machemer/Smithsonianmag.com
Ancient food waste holds the history of the Sahara desert’s climate in its bones. Nearly 5,000 years worth of fossilized leftovers in the Takarkori rock shelter in southwestern Libya show ancient humans’ transition from a mostly-fish diet to one that featured more land animals like sheep and cattle, according to new research published on February 29 in the journal PLOS One.
About 11,000 years ago, the Sahara, which is now a hyperarid desert, was in a green phase. Sediment and pollen data show that the iconic desert was once covered in lakes, rivers, and wetlands, but between 4,500 and 8,000 years ago, the humid savannah transitioned into the dry, windy desert that’s recognizable today. Residing in rock shelters like the one researchers studied at Takarkori, ancient human hunter-gatherers lived through it all.
Researchers from Belgium and Italy analyzed over 17,000 animal remains from the rock shelter. The bones were marked with cuts and burns, signs that they were cooked and eaten by humans.
The researchers found that catfish and tilapia bones made up 90 percent of the finds from the first few thousand years that humans inhabited the shelter, starting about 10,000 years ago. But of the more recent 4,650- to 5,900-year-old remains, only about 40 percent were fish bones…