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An international team of researchers, including a University ofVirginia professor, has found that two ink sacs from160-million-year-old giant cephalopod fossils discovered two yearsago in England contain the pigment melanin, and that it isessentially identical to the melanin found in the ink sac of amodern-day cuttlefish. The finding - in an extremely rare case of being able to studyorganic 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 theJurassic period, and that melanin could be preserved intact in thefossils of a range of organisms. "Though the other organic components of the cephalopod we studiedare long gone, we've discovered through a variety of researchmethods that the melanin has remained in a condition that could bestudied in exquisite detail," said John Simon, one of the studyauthors, a chemistry professor and the executive vice president andprovost at U.Va. One of the ink sacs studied is the only intact ink sac everdiscovered. Phillip Wilby of the British Geological Survey found it inChristian Malford, Wiltshire, England, west of London near Bristol.He sent samples to Simon and Japanese chemist Shoskue Ito, bothexperts on melanin, who then engaged research colleagues in theUnited States, the United Kingdom, Japan and India to investigatethe samples using a combination of direct, high-resolution chemicaltechniques to determine whether or not the melanin had beenpreserved. It had. The investigators then compared the chemical composition of thefossil melanin to the melanin in the ink of the modern cuttlefish,Sepia officinalis, common to the Mediterranean, North and Balticseas. They found a match. "It's close enough that I would argue that the pigmentation in thisclass of animals has not evolved in 160 million years," Simon said."The whole machinery apparently has been locked in time and passeddown through succeeding generations of cuttlefish. It's a veryoptimized system for this animal and has been optimized for a longtime." Generally animal tissue, made up mostly of protein, degradesquickly. Over the course of millions of years all that is likely tobe found from an animal is skeletal remains or an impression of theshape of the animal in surrounding rock. Scientists can learn muchabout an animal by its bones and impressions, but without organicmatter they are left with many unanswered questions. But melanin is an exception. Though organic, it is highly resilientto degradation over the course of vast amounts of time. "Out of all of the organic pigments in living systems, melanin hasthe highest odds of being found in the fossil record," Simon said."That attribute also makes it a challenge to study. We had to useinnovative methods from chemistry, biology and physics to isolatethe melanin from the inorganic material." The researchers cross-checked their work using separatecomplementary experiments designed to capitalize on variousmolecular features unique to melanin and determined the morphologyand chemical composition of the material. This combination ofin-depth, multidisciplinary techniques is not normally used bypaleontologists to study fossil samples. "I think the strength of this paper is that it is not tied to asingle method," Simon said. "Any one technique would have broughtsome insights, but potentially more questions than insights. It wasreally the more holistic approach that fully characterized it andallowed us to actually do a real comparison between what existedduring the Jurassic period and what exists now. "It's also given us a handle on ways of identifying organiccomponents in fossils that might have been missed using standardmethods." The study is published online in the May 21 edition of the journalProceedings of the National Academy of Sciences. I am an expert from roof-rollformingmachine.com, while we provides the quality product, such as Sandwich Panel Production Line , Gutter Forming Machine, Double Layer Roll Forming Machine,and more.
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