EAR BONE OF WHALE - 15 million years old - South Carolina

   
EAR BONE OF WHALE (TYMPANIC BONE)

15 million years old (Miocene period)
  
South Carolina, USA
  
Land mammals receive sound through the air and have ear bones that are attached to the skull.  Underwater this makes identifying the direction of sounds difficult because of unwanted vibrations coming from the skull. Whales, that are descended from land mammals, have solved this problem by partially separating the bones from the skull.  

The tympanic bone is unique to whales. Unlike most of the other bones in a whale’s skeleton it is very hard, dense and heavy, which is why it is most easily fossilised.  
   
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