The bizarre animal, named Bathonymus yucatanensis, has a distinctive creamy-yellow shell - and is an example of ocean gigantism. Some creatures that dwell in the deep tend to grow much bigger than their relatives in shallower waters or on land. Most isopods measure less than 10 mm (0.4 in) in length, however the 20 species in the 'supergiant' Bathynomus genus grow to be more than 30 times larger. The mysterious and primitive group that inhabits the benthic zone - the ocean's deepest reaches, rarely explored in person.