Steller's sea cow
Based on these and other observations, Steller later wrote "De Bestiis Marinis" ('On the Beasts of the Sea'), describing the fauna of the island, including the northern fur seal, the sea otter, Steller's sea lion, Steller's sea cow, Steller's eider and the spectacled cormorant. Steller claimed the only recorded sighting of the marine cryptid Steller's sea ape.