The remains of a tiny animal, preserved for 425 million years in rocks located in what is now the U.K., have just been discovered by an international team of researchers.
The creature — related to crabs, lobsters and shrimp — is an ostracod, or a type of crustacean sometimes known as seed shrimp. It represents a new species, Pauline avibella, in memory of the late wife of David Siveter, who led the research project.
The 0.4-inch-long animal was found, not
only with its shell, but also with its soft parts — body, limbs, eyes, gills
and digestive system. Such well-preserved remains from that ultra prehistoric period are near unheard of in the fossil record.
"The two ostracod specimens discovered represent a genus
and species new to science, named Pauline avibella," Siveter, of the University of Leicester Department of
Geology, said in a press release. "The genus is named in honor of a special person and avibella
means 'beautiful bird,' so-named because of the fancied resemblance of a
prominent feature of the shell to the wing of a bird."
The discovery of the tiny shelled animal was made in Herefordshire, Welsh Borderland. The rocks at the site
date to a time when southern Britain
was a sea area on a small continent situated in warm, southerly
subtropical latitudes. The ostracods and associated marine animals
living there were covered by a fall of volcanic ash that preserved them
frozen in time.
"Ostracods are the most abundant fossil arthropods, occurring
ubiquitously as bivalved shells in rocks of the last 490 million years,
and are common in most water environments today," Siveter said. "The find is important
because it is one of only a handful preserving the fossilized
soft-tissues of ostracods."
He continued, "The preservation of soft-parts of animals is a very rare occurrence
in the fossil record and allows unparalleled insight into the ancient
biology, community structure and evolution of animals – key facts that
that would otherwise be lost to science."
As the image here shows, the fossils were reconstructed virtually, by using a technique that involves grinding each specimen down, layer by layer, and then photographing it at each stage. It took 500 such "slices" to create the image.
Siveter shared, "Fossil discoveries in general help
elucidate our own place in the tree of life. This discovery adds another
piece of knowledge in the jigsaw of understanding the diversity and
evolution of animals."
"It is exciting to discover that a common group of fossils that we
thought we knew a lot about may well have been hood-winking us as to
their true identity, which we now realize because we have their
beautifully fossilized soft-parts. A case of a 'wolf in sheep's
A paper describing specimens of the extremely rare species is in the latest Proceedings of the Royal Society B.
Image: The fossil Pauline avibella. Credit: David J. Siveter, Derek E.
G. Briggs, Derek J. Siveter, Mark D. Sutton and Sarah C. Joomun