DSV Alvin
The IMAX film "Volcanoes of the Deep Sea" describes the search for a living animal that produces the "Paleodictyon", using the deep-water submersible DSV Alvin near volcanic vents that lie underwater in the Mid-Atlantic Ridge. They found and took samples from many of the "Paleodictyon nodosum" honeycomb burrows. However, no creatures were found in any of them. They theorized that the burrows were being used for cultivating/trapping bacteria by whichever creature created them.