DSV Alvin
The IMAX film "Volcanoes of the Deep Sea" describes the search for "Paleodictyon nodosum", using the deep-water submersible "DSV Alvin" near volcanic vents that lie 3500 meters (12,000 feet) underwater in the Mid-Atlantic Ridge. Samples were taken from several honeycomb burrows, however no creatures were found in any of them. They theorized that the burrows were being used for bacterial farming by whichever creature created them.