The pigment molecules that give living things their dazzling colours are delicate things that degrade over time, which is why the palaeontological specimens in museums often look dull. But a trick discovered in the 1970s helped: dipping ancient shells in sodium hypochlorite (the active ingredient in household bleach) and then exposing them to ultraviolet light revealed colours and patterns that could not otherwise be seen. The approach remained little-known, but this week a study in PLOS ONE hugely extends the age of shells examined with it. Specimens from the Jurassic period, unearthed in France, showed complex patterns that researchers thought did not arise until 100m years later. The shells’ colours arise from leftover, degraded pigment fragments, so they are unlikely to be those the creatures displayed in life. But the patterns will be a great help in piecing together how these ancient gastropods and bivalves led to today’s.
from The Economist: Science and technology http://ift.tt/1G9aS4u
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