Researchers working in Antarctica have made an unexpected discovery: colonies of stationary animals—likely sponges and related creatures—attached to a boulder deep beneath the ice, NBC reports. Geologists boring through the 3,000-foot-thick ice of the Filchner-Ronne Ice Shelf to take sediment samples from the ocean floor ran into the rock and sent down a camera. “It was a genuine surprise to see these animals there,” Huw Griffiths, a marine biologist and lead author of the new study documenting the find, told CNN. “It’s amazing,” he said, speaking to NBC, “because no one has ever seen these before.” In the past, small mobile creatures—things like fish, worms, jellyfish, and crustaceans—have been found far beneath the ice, the Guardian notes. But stationary filter-feeders have not.
Many scientist thought that was because of the hostile environment created by total darkness, a dearth of food sources, and frigid temperatures. Sponges and other filter feeders survive by feeding on floating material from plants and animals. The boulder hosting the animals is about 150 miles from the open sea. Based on the currents, the food they ingest may come from more than 900 miles away, the researchers say. “It was a real shock to find them there, a really good shock, but we can’t do DNA tests, we can’t work out what they’ve been eating, or how old they are. We don’t even know if they are new species, but they’re definitely living in a place where we wouldn’t expect them to be living,” Griffiths told the Guardian. (Read more Antarctica stories.)