How do we know it’s a girl?

Most male mammals have a bone in the penis, a baculum. Most of our closest relatives have such a bone, but humans do not. The closest relatives of Ida’s species also had one. The first find of a primate in the Messel quarry had one. Because Ida’s skeleton is so complete, we can clearly see that there is no baculum between her thigh bones.

Røntgenbilde av Idas hofteparti og bakføtter
The X-ray of Ida’s lower body clearly shows that there is no penis bone. Photo: PloS One
Lower body of Europolemur koenigswaldi
The lower body of Europolemur koenigswaldi, the first primate found in the Messel quarry. Photo: Wighart von Koenigswald, University of Bonn

Published June 23, 2010 1:02 PM - Last modified Jan. 13, 2015 4:11 PM