Five hidden mussels walk out of the mud — and into the record books

For 20 years, researchers have waded through muddy rivers in Missouri, Arkansas, Mississippi, Alabama, Louisiana and Texas — snorkel and mask on, feeling along the bottom for mussels to take back to the lab. The payoff is five brand-new species in the genus Obovaria, described in the journal Zootaxa by scientists from Shedd Aquarium, Arkansas State University and the US Geological Survey. Freshwater mussels are the most endangered group of animals in North America, and you cannot protect what you have not named. Now that these five are officially recognised, scientists can map where each one lives and aim recovery efforts where they will count.