Members of this genus are characterized by their deep-sea habitat, clear bodies, and ability to engorge themselves with water to become larger when threatened.
The formation includes fluvial (river), deep-sea, and near-shore deposits, and the mammalian fauna probably comes from an estuary, tidal flat, or coastal plain.
Future deep-sea waste disposal activities that could be significant by 2025 include emplacement of sewage and sludge, carbon-dioxide sequestration, and disposal of dredge spoils.