Carnivora

Carnivora is a group of mammals known as carnivorans, which are mainly meat-eaters. They make up one of the largest groups of mammals, with at least 279 different species. These animals live all over the world, from very cold places to deserts and even in the oceans. They come in many shapes and sizes, each adapted to their own special way of living.

Carnivorans are split into two main groups. One group, called Feliformia, includes true cats and other cat-like animals such as hyenas and mongooses. Most of these live in Europe, Asia, and Africa, but cats also live in the Americas, having crossed over through the Bering land bridge. The other group, Caniformia, includes true dogs, bears, raccoons, skunks, and seals, among others. These animals are found everywhere and have a huge variety in how they look, eat, and behave.

Etymology

The word Carnivora comes from old Latin words. One word, carō (with the stem carn-), means "flesh." The other word, vorāre, means "to devour." Together, they give us the name for these meat-eating animals.

Phylogeny

Carnivorans, a group of meat-eating mammals, have ancient roots. Their earliest known ancestors appeared in North America 6 million years after a major event called the Cretaceous–Paleogene extinction event. These early creatures looked like small weasels or genets and lived quietly at night on the forest floor or in trees.

After some other meat-eating animals disappeared, carnivorans expanded and took over many roles. By the time of the Miocene epoch, carnivorans had diversified into many families and became dominant predators in places like Eurasia and North America.

Systematics

Evolution

Carnivorans belong to a group of mammals called Laurasiatheria, which also includes bats and ungulates. Within this group, carnivorans are placed in the clade Ferae, which includes pangolins and several extinct carnivorous groups.

Carnivorans first appeared about 60 million years ago. They split into two main groups: the cat-like feliforms and the dog-like caniforms. Over time, carnivorans became important predators on land.

Classification of the extant carnivorans

In 1758, Carl Linnaeus grouped all known carnivorans together. By 1821, the group received its modern name. Early classifications divided carnivorans into two groups: land animals and marine animals like seals.

Later studies showed that some groups were not correctly placed. For example, some animals once thought to be closely related are now known to belong to different families. This research used genetics, shape, and fossil records to better understand how these animals are related.

Anatomy

Skull

Carnivorans have strong teeth, including large canine teeth, and usually three incisor teeth on each side of their jaws, except for the sea otter, which has only two lower incisors. Their skulls are strong with a special bone arch and often a bony ridge on top. Most have their eyes at the front of their faces. The shape of their faces and number of teeth can vary; for example, dogs have longer faces with more teeth, while cats have shorter faces with fewer teeth.

Postcranial region

Carnivorans all walk on four legs, with most having five toes on the front feet and four on the back feet. Their feet can have soft pads, and they may walk on their toes or the full palm of their feet depending on the species. In animals like seals, the legs are changed into flippers for swimming. Most carnivorans have fur that changes with the seasons, with thicker, denser fur in cold climates and thinner fur in warmer areas. Some animals, like the arctic fox, even change their fur colour with the seasons.

Sexual dimorphism

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Relationship with humans

Carnivorans are very important to humans. The dog was the first animal to be domesticated by people, and it was also the first species of any kind to be tamed. Over the past 10,000 to 12,000 years, people have bred dogs for many different jobs, and today there are more than 400 types of dogs. The cat is another animal that lives with humans.

Many other carnivorans are famous and loved by people, and they are often called charismatic megafauna. Some cultures see animals like the lion as symbols of power and royalty. However, some carnivorans such as wolves and big cats have been hunted in many places, which has caused some of them to disappear from certain areas. Changes in their homes and climate change have also made life harder for many of these animals. Sadly, a few types of carnivorans have disappeared completely since the 1600s. These include the Falkland Island wolf, the sea mink, the Japanese sea lion, and the Caribbean monk seal.

Some animals like the red fox and the stoat have been taken to places like Australasia, where they have caused problems for animals that live there.