Tens of millions of years ago, cephalopods were hiding from enemies in clouds of ink. And it turns out thatcuttlefish today producing ink that's almost identical. Researchers found fossils of two giant celphalopods that swam in seas more than 160 million years ago. And each one contained preserved inksack. Analysis of this sacs revealed that some melanin pigment the stuff makes ink dark had survived. Plus, the chemical make up of the melanin was virtually the same as the pigment found in modern day cuttlefish ink. The work is the proceedings of National Academy of Science. It's rare to find preserve soft tissue in the fossil record. In addition, bimolecules often break down, leaving none of orginal organ compounds . Melanin however has sturdy structure that was resist this fate. 

 

And method this research used to isolate from the fossils could help other palaeontologists better identify preserve organic molecules and their functions. The finding also demonstrates that when something works evolution usually leaves it alone, because that ink broke, don't fix it.