steller's sea cow: extinct large sirenian mammal formerly found near the Asiatic coast of the Bering Sea
mammal: any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk
hyaluronidase: an enzyme (trade name Hyazyme) that splits hyaluronic acid and so lowers its viscosity and increases the permeability of connective tissue and the absorption of fluids