Fossils shed light on very different world

When most people hear “fossil,” the first image that springs to mind is of a dinosaur – or perhaps, if you live in North Carolina, a large shark tooth.

Though these creatures were compelling in their own rights, they are not the oldest fossils in North Carolina. For these, we have to go all the way back to the Ediacaran Period (635 million to 542 million years ago). Found in sediments from Stanly and Davidson counties, the oldest undisputed fossils from the state are impressions of soft-bodied marine organisms and the preserved traces of their movements across the seafloor.

These fossils are not particularly showy, but they are nonetheless important because they represent some of the earliest evidence for multicellular life.

Approximately 547 million years in the past, the world was different from the one we inhabit. Imagine a world with no mammals, no birds, not even a cockroach. There was no terrestrial life to speak of, yet the oceans were teeming with living organisms.

Put on your imaginary scuba gear and have a look around. You won’t see seashells, crabs or starfish, but you will see a bunch of soft-bodied creatures with unfamiliar names such as Pteridinium, Swartpuntia and Aspidella. If you put your foot down, you will probably notice that the seafloor is covered in a scum-like layer known as a microbial mat. All the animals around you are living on, in, or slightly under this mat. It is this mat that will ultimately preserve these organisms for millions of years.

Some of these animals look like plant fronds swaying with the currents; some resemble large flatworms. Others just look like tubes. And almost none of them will look familiar to you.

This unfamiliarity is one of the great joys and also one of the great frustrations for paleontologists. Because paleontologists generally use the present as a key to the past, fossils from the Ediacaran Period can be difficult to identify and can stir much debate: Which group of organisms do they belong to (especially when they are just fragments)? Paleontologists who work with fossils from this period have had to do some major adjustments to their worldview, and perhaps now that you’ve read about these enigmatic animals, you will, too.

See for yourself: Some of North Carolina’s Ediacaran fossils are on exhibit on the third floor of the Nature Research Center at the N.C. Museum of Natural Sciences in downtown Raleigh.

Patricia Weaver is collections manager geology/paleontology for the N.C. Museum of Natural Sciences. Her research focuses on fossil and extant coleoid cephalopods. In particular, she studies taxonomy of fossil cuttlefish, and biochemistry of fossil and extant squid, octopus and cuttlefish.