amnhnyc: It’s a ferocious Fossil Friday in honor of Shark Week!The evolution of sharks can be traced back over 400 million years. Their teeth are among the most abundant vertebrate fossils, but complete fossil sharks are exceptionally rare. Outwardly,
amnhnyc: It’s a ferocious Fossil Friday in honor of Shark Week!The evolution of sharks can be traced back over 400 million years. Their teeth are among the most abundant vertebrate fossils, but complete fossil sharks are exceptionally rare. Outwardly,