FILCHNER-RONNE ICE SHELF, ANTARCTIC — Scientists are rethinking the limits of life on Earth after stumbling on a group of strange organisms living deep under a 900-meter-thick ice shelf.

The Guardian reports that researchers accidentally found a life-bearing rock after sinking a borehole through the Filchner-Ronne ice shelf to obtain a sediment core from the seabed.

While the rock spoiled their chances of obtaining the core, footage from a video camera captured unexpected images of organisms living far beneath an ice shelf.

Surveys of Antarctic marine life have never previously found such stationary filter-feeders, which survive by ingesting food that falls down on them.

It was assumed that the total darkness, the lack of food and the freezing water was too hostile for them.

Footage of the boulder shows that it is home to at least two types of sponge, one of which has a long stem that opens into a head.

Organisms that look like tube worms, or stalked barnacles, also appear to be growing on the rock.

Scientists theorize the animals feed on dead plankton that is carried more than 600 kilometers by currents before reaching them.