It existed during the Permian and Jurassic periods . It began breaking up during the Jurassic, forming Gondwanaland and Laurasia . Pantropical Spotted Dolphin Also known as the Spotted, White-Spotted, or Brindled Dolphin, this small, toothed whale lives in tropical waters worldwide. Gray whales and other cetaceans have skin parasites such as barnacles and whale lice. Lice are an example of a parasite that affects many animals.
Parasitism is a type of symbiosis .
Pectoral Pectoral means of, pertaining to, or near an animal's chest area. Pectoral flippers Pectoral flippers are wide, flat limbs located in the chest area that many marine animals use for swimming. Whales and other cetaceans have pectoral flippers. Pelagic Pelagic means of, pertaining to, or living in the open ocean, either at the surface or at intermediate depths. The period is the basic unit of geological time in which a single type of rock system is formed, lasting tens of millions of years.