May 21, 2012 An international team of researchers, including a University of Virginia professor, has found that two ink sacs from 160-million-year-old giant cephalopod fossils discovered two years ago in England contain the pigment melanin, and that it is essentially identical to the melanin found in the ink sac of a modern-day cuttlefish.
The study is published online in the May 21 edition of the journal Proceedings of the National Academy of Sciences.
The finding in an extremely rare case of being able to study organic material that is hundreds of millions of years old suggests that the ink-screen escape mechanism of cephalopods cuttlefish, squid and octopuses has not evolved since the Jurassic period, and that melanin could be preserved intact in the fossils of a range of organisms.
"Though the other organic components of the cephalopod we studied are long gone, we've discovered through a variety of research methods that the melanin has remained in a condition that could be studied in exquisite detail," said John Simon, one of the study authors, a chemistry professor and the executive vice president and provost at U.Va.
One of the ink sacs studied is the only intact ink sac ever discovered.
Phillip Wilby of the British Geological Survey found it in Christian Malford, Wiltshire, England, west of London near Bristol. He sent samples to Simon and Japanese chemist Shoskue Ito, both experts on melanin, who then engaged research colleagues in the United States, the United Kingdom, Japan and India to investigate the samples using a combination of direct, high-resolution chemical techniques to determine whether or not the melanin had been preserved.
The investigators then compared the chemical composition of the fossil melanin to the melanin in the ink of the modern cuttlefish, Sepia officinalis, common to the Mediterranean, North and Baltic seas.
They found a match.
"It's close enoug
|Contact: Fariss Samarrai|
University of Virginia