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| Caniforms Fossil range: Paleocene - Recent |
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Caniformia, or Canoidea (literally "dog-like") are a suborder within the order Carnivora. They typically possess a long snout and non-retractile claws (in contrast to the cat-like carnivores, the Feliformia). The Pinnipedia (seals, sea lions, and walruses) evolved from caniform ancestors and are accordingly assigned to this group. All members of this group (with the exception of Canidae) have non-retractile claws and tend to be plantigrade. Another trait that separates them from the Feliformia is that they have more teeth. They have a longer rostrum with less specialized carnassials. They tend more towards omnivorous and opportunity-based feeding, while the feliforms are more specialized in eating meat. Caniforms have single-chambered or partially divided auditory bullae, composed of a single bone, while in feliforms the auditory bullae are double-chambered, composed of two bones joined by a septum.
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Extant families
Caniformia consists of twelve families, with nine extant and three extinct. At one time, Hyaenidae were included, but are now grouped with feliforms. Caniforms are found all over the world (even when not counting dogs), even mainland Antarctica, as seals have no natural land predators so they can rest on land.
The Family Canidae (canids, commonly known as either dogs or canines) includes wolves, dogs, foxes and so on. They are the most social of all the caniforms, living in packs. The dog is the most diverse of all mammals in terms of body structure. The Canidae family is divided into the "true dogs" of the tribe Canini and the "foxes" of the tribe Vulpini. The two species of the basal Caninae are more primitive and don't fit into either tribe.
The Family Ursidae (the bears) are the largest of all the land caniforms. They range from the large polar bear (males, 775–1500+ lb) to the small sun bear (males, 66–132 lb) and from the endangered giant panda to the very common black bear. Common characteristics of modern bears include a large body with stocky legs, a long snout, shaggy hair, plantigrade paws with five nonretractile claws, and a short tail. While the polar bear is mostly carnivorous and the giant panda feeds almost entirely on bamboo, the remaining six species are omnivorous, with largely varied diets including both plants and animals.
The Family Ailuridae (the red panda) was once thought to be either part of the Procyonidae or the Ursidae. It now belongs to its own family. It is found in China, but may have also lived in North America.
The Family Mephitidae (the skunks), once thought to be part of the Mustelidae, is now a group in its own right. This group is famous for its foul smell. There are 11 species of skunks, which are divided into four genera: Mephitis (hooded and striped skunks, two species), Spilogale (spotted skunks, two species), Mydaus (stink badgers, two species), and Conepatus (hog-nosed skunks, five species). The two skunk species in the Mydaus genus inhabit Indonesia and the Philippines; all other skunks inhabit the Americas from Canada to central South America.
The Family Mustelidae (the weasels and otters) is the most diverse of the group. The members are famous for their fierce hunting instinct and (usually) streamlined body. Within a large range of variation, the mustelids exhibit some common characteristics. They are typically small animals with short legs, short round ears, and thick fur. Most mustelids are solitary, nocturnal animals, and are active year-round. Mustelids are predominantly carnivorous, although some will sometimes eat vegetable matter. While not all mustelids share an identical dentition, they all possess teeth adapted for eating flesh, including the presence of shearing carnassials.
The Family Procyonidae (the raccoons, coatis, etc.) Procyonids are smallish animals, with generally slender bodies and long tails. (The common raccoon tends to be bulky.) Except for the kinkajou, all procyonids have banded tails, and distinct facial markings. These are especially visible in the raccoons. Like bears, procyonids are plantigrade, walking on the soles of their feet. Most species have non-retractile claws. It has been suggested that early procyonids were an offshoot of the canids that adapted to a more omnivorous diet.1
The Family Phocidae (the true seals)
The Family Otariidae (the eared seals and sea lions)
The Family Odobenidae (the walrus)
Evolutionary history
The caniforms first appeared as tree-climbing, marten-like carnivores in the Paleocene (65–55 million years ago). Miacis was probably an early caniform. Like many other early carnivorans, it was well suited for an arboreal climbing lifestyle with needle sharp claws, and had limbs and joints that resemble those of modern carnivorans. Miacis was probably a very agile forest dweller that preyed upon smaller animals, such as small mammals, reptiles, and birds, and might have also have eaten eggs and fruits, making Miacis an omnivore.
Classification
| Caniformia |
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