However, beaks from mature adults have only been recovered from those animals large enough to take such prey (i.e. sperm whales and sleeper sharks), while the remaining predators are limited to eating juveniles or young adults.
The knifetooth dogfish, Scymnodon ringens, is a harmless sleeper shark of the family Somniosidae, found in the eastern Atlantic, from Scotland to Spain, Portugal, and Senegal, and the southwest Pacific from New Zealand, between latitudes 58°N and 15°N, at depths of between 200 and 1,600 m.
The shortnose velvet dogfish, Centroscymnus cryptacanthus, is a sleeper shark of the family Somniosidae, found between latitudes 33°N and 38°S in the southwest Atlantic Ocean, from Uruguay, the eastern Atlantic, from Madeira and Senegal, and also off the west coast of South Africa.
The smallmouth knifetooth dogfish, Scymnodon obscurus, is a harmless sleeper shark of the family Somniosidae, found in the central Atlantic between latitudes 65°N and 36°S, from the surface to 1,450 m.
The velvet dogfish, Zameus squamulosus, is a harmless sleeper shark of the family Somniosidae, found around the world between latitudes 64°N and 48°S, from the surface to 2,000 m.