October 2018    
  Ancient toddlers took to the trees with the help of a highly mobile big toe.  
  Modern kids climb trees for fun. Ancient kids climbed for protection, with the help of their toe anatomy. (Photo courtesy UChicago Medicine)  
  When your toddler starts exploring, you might wish you had eyes in the back of your head. But 3 million years ago, you'd need them on top of your head, too, because those kids were likely up a tree.  
  In 2000 Zeray Alemseged, professor of organismal biology and anatomy, discovered a nearly complete 3.3 million-year-old skeleton of a young female Australopithecus afarensis in the Dikika region of Ethiopia. Selam, as the fossil was named, is the same species as the adult Lucy and was found in the same area.  
  These human ancestors walked upright on two legs, but Selam's tiny foot--the size of a modern human thumb--shows that the kids still had tree-climbing traits like their apelike cousins. A more curved big toe joint helped them grasp limbs and branches better than adults.  
  The foot of the 'world's oldest child' shows researchers how our ancestors moved. (Video by National Geographic)  
  This adaptation gave the vulnerable young extra protection. "If you were living in Africa 3 million years ago without fire, without structures, and without any means of defense, you'd better be able to get up in a tree when the sun goes down," says Jeremy DeSilva, a Dartmouth professor and lead author of the study. True for adults--even more so for the kids.  
  "The skeleton continues to provide new, really amazing insight in terms of the many adaptations that our early human ancestors had," Alemseged said. "Now to identify features that are slightly apelike in an otherwise very humanlike creature is a bit of a surprise."  
  Five more fossil finds  
Meet some of the fantastic beasts UChicago fossil hunters helped introduce to the scientific record and the popular imagination.
The jawbone of an early protomammal (a mammal-reptile hybrid) shows that true mammals arose later than previously thought.
A son describes how his UChicago paleobiologist father applied big data to dino digging and helped elevate paleontology's reputation.
A fossilized protomammal skull found in Utah offers evidence that the supercontinent Pangea broke apart later than previously believed.
Discovery of the oldest gliding mammals helps us understand our own lineage.
  Set in stone  
  Remains of Homo floresiensis, nicknamed "Hobbit," have so far only been found on the Island of Flores, Indonesia--apparently an ideal fossil-making location. The three-foot-six early humans lived between 100,000 and 50,000 years ago. (Photo courtesy the Smithsonian Institution)  
  Anyone can become a skeleton, but of the 320 million people living in the United States today, only one might become a fossil. Susan Kidwell, the William Rainey Harper Professor in Geophysical Sciences, explains how to up your chances.  
  Get buried quickly underneath a body of water. You want to end up at low elevation so it's a sink for sediment, says Kidwell, "and preferably with standing water--a pond, lake, estuary or ocean--so that anoxic conditions might develop." This environment will protect your remains from scavengers, bacteria, and the elements.  
  Turn to stone. Permineralization, best achieved when mineral-rich water flows through bones depositing iron and calcium, takes millions of years, so be patient. Leave beautiful blue-green stone bones by bringing along copper and nickel.  
  Avoid fault lines. If your fossil is at the edge of a tectonic plate, it might get pushed deep into the earth and melt.  
  Get found. If you planned far enough ahead, you picked a place where erosion would eventually expose you, like inland seas that fill with sediment over time.  
  Or go rogue. Leave your legacy encased in amber, in a tar pit, or in a cave, turned into a human stalagmite.  
  Want to dig deeper? Read the full BBC story.  
  In case you missed it  
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