Using the fossil record to accurately estimate the timing and pace of past mass extinctions is no easy task, and a new study highlights how fossil evidence can produce a misleading picture if not interpreted with care.
Using the fossil record to accurately estimate the timing and pace of past mass extinctions is no easy task, and a new study highlights how fossil evidence can produce a misleading picture if not interpreted with care.
Florida Museum of Natural History researchers used a series of 130-foot cores drilled from the Po Plain in northeastern Italy to test a thought experiment: Imagine catastrophe strikes the Adriatic Sea, swiftly wiping out modern marine life. Could this hypothetical mass extinction be reconstructed correctly from mollusks – hard-shelled animals such as oysters and mussels – preserved in these cores?
When they examined the cores, the results were “somewhat unnerving,” said Michal Kowalewski, Thompson Chair of Invertebrate Paleontology and the study’s principal investigator.
Paleontologists use the age of a species’ last-known fossil to estimate the timing of extinction. A sudden extinction in the Adriatic Sea today should leave the youngest remains of many mollusk species in the sediments currently forming on the shore and seabed, the “ground zero” of the hypothetical extinction event. But the team found only six of 119 mollusk species – all of which are still alive in the area – at the top of the cores. Instead, the last fossil examples of many of these species often appeared in clusters dotted throughout the cores, suggesting smaller bursts of extinctions over a longer timeline, not a single massive die-off.
Read more at Florida Museum of Natural History
Photo Credit: dimitrisvetsikas1969 via Pixabay
