3. 9,900-year-old skull
An ancient human skull found in the submerged Tulum cave system revealed that more than one group of humans arrived in Central and North American, complicating what we know about human settlement in this region of the globe.
7. Ancient jawbone
This 160,000-year-old jawbone unearthed from a cave in Tibet appears to belong to an enigmatic ancient human ancestor called the Denisovans. The finding allowed scientists to start piecing together the history of these mysterious early humans.