Unlocking Secrets of How Fossils Form
When most organisms die, they
biodegrade and leave little behind. But if they get trapped in sediments that
harbor few bacteria and loads of dissolved minerals, they can become fossilized
and preserved for millions of years. Scientists use a variety of techniques on
the ancient specimens to determine details about lifestyles and diets, as well
as information about the geographical distribution of the creatures. One of
those methods called scanning electron microscopy, or SEM, showed particular
promise for revealing new information about fossils. So Amauri J. Paula and
colleagues expanded on this method.
The researchers used a
large-field SEM approach to analyze a shrimp fossil from the Araripe Basin, a
place in northeastern Brazil known among paleontologists as a treasure trove of
flying pterosaur remains. The shrimp specimen dates back to the Cretaceous
period, when dinosaurs still roamed the planet. The technique provided evidence
for the first time that a rare fossilization process occurred in the basin. It
also showed that the fossil over millions of years developed a surprising
fractal characteristic -- a still-unexplained, repeating pattern most commonly
recognized in snowflakes but also found in structures as large as spiral
galaxies.
