This order includes all placental mammals whose last upper premolar and first lower molar have become sharp carnivorous teeth. The canines have developed into fangs. The name of this order refers to the diet of Carnivora, which feed mainly on other vertebrates that they stalk and hunt. They have sharp claws and very powerful jaws that allow them to overpower their prey. There are some exceptions, such as the giant panda, which is a herbivore, the binturong, which is mainly a frugivore, and bears and viverrids, which will voluntarily seek out fruit to supplement their diet. On all continents, carnivores are generally the final link in the food chain. They are essential to the balance of ecosystems because they regulate herbivore populations and are indirect resources for scavengers. The old classification separated Carnivora into two groups, Fissipedia, which included dogs, raccoons, cats, civets, hyenas, pandas and polecats, and Pinnipedia, which included marine mammals such as seals, sea lions, walruses and sea lions. Today, the order Carnivora is divided into two suborders: Caniformia, which includes dogs, wolves, bears, pandas, skunks, walruses, sea lions and seals, and Feliformia, which includes felines, fossas, mongooses, hyenas, civets and genets.