Cuttlefish are mollusks that look somewhat like squid. They have an internal, hard, supportive structure with soft organs around and inside it. This resilient "cuttlebone" is made of cleverly woven strands of a biochemical material called chitin and mixed with a hard biomineral called aragonite.
A team of paleontologists found a supposedly 34 million-year-old fossil cuttlebone that still had both the original aragonite and chitin. This is significant, because one might expect the hard aragonite to persist in the fossil record, but not the organic chitin or protein. The chitin, which is made of sugars tightly bonded into molecular chains, would have spontaneously degraded and been long gone after only thousands of years.
