Crocodile belongs to Reptilia class which has four chambered heart. Lemur teeth are embedded in the sockets of two which is known as thecodont. In Obelia, polyps reproduce medusae asexually and medusae form the polyps sexually. Such alternation of sexual phases in the life cycle is called metagenesis. Parapodia are present in Annelida, while sea urchin is a Echinodermata.