A new creature emerges from forest in Mexico

 The creature was tiny, about the size and color of a grain of rice. Dan Distel, director of the Ocean Genome Legacy Center at Northeastern University in Boston, wasn’t exactly sure what it was, other than a mussel of some kind. He put the wee bivalve in a petri dish and asked a colleague to set it aside.

“By the time we got back to the lab, the little bugger had crawled out of the dish,” he recalls with some chagrin. “And we couldn’t find it.”

It was months later that they found another one, and Dr. Distel realized that the mussel looked oddly familiar. It resembled the giant mussels found at deep-sea hydrothermal vents 1,500 feet below the ocean’s surface, which have gills that contain bacteria that let the mussels gain nutrients from corrosive hydrogen sulfide bubbling from the Earth’s crust. But this mussel was tiny and pale and, strangest of all, lived a mere 60 feet or so down. DNA analysis soon confirmed that this mussel was a new species, which the scientists named Vadumodiolus teredinicola. It is the first mussel of this group ever seen at depths of less than 300 feet. The existence of this shallow-water cousin, the researchers suggest, could help explain how the giant mussels ended up deeper down.

Dr. Distel and his colleagues discovered the mussel while they were investigating an ancient underwater forest off the coast of Alabama. During the last ice age, bald cypresses grew in what was then a swamp a hundred miles from the ocean. Then, sometime between 45,000 and 70,000 years ago, as sea levels rose, the trees were swallowed by the advancing sea. Swirling sands wrapped the dead trees in a natural sarcophagus. For millenniums, all was still in the forest, until heavy waves stirred up by one of the hurricanes of 2004 scooped away the sand. Fishermen were startled to discover trees on the otherwise featureless bottom of the Gulf of Mexico 10 miles from dry land, and a journalist, Ben Raines, helped bring the site to scientists’ attention.