Think “mass extinction” and you probably envision dinosaurs dropping dead in the long-ago past or exotic tropical creatures being wiped out when their rainforest habitats are decimated. But a major mass extinction took place in North America in the first half of the 20th century, when 47 species of mollusk disappeared after the watershed in which they lived was dammed.
Now, a population of one of those species — a freshwater limpet last seen more than 60 years ago and presumed extinct — has been found in a tributary of the heavily dammed Coosa River in Alabamas Mobile River Basin. Researchers from the University of Michigan, the Alabama Aquatic Biodiversity Center and the Kentucky State Nature Preserves Commission reported the rediscovery May 31 in the online, open-access journal PLoS ONE.
The story of Rhodacmea filosas disappearance and reappearance is both a conservation success story and a cautionary tale for other parts of the world where rivers are being dammed, said Diarmaid Ó Foighil, professor of ecology and evolutionary and a curator at the U-M Museum of Zoology. Its also an example of how museum specimens collected generations ago can inform scientists of today.