A Dog is a Man's Best Friend

The History of dogs

Dogs belong to the Canid family (Canidae).

Dogs first appeared about 40 million years ago, before any other carnivore families like bears or cats.

Carnivores have a pair of teeth similar to blades that are called carnassials. These teeth are like scissors and can slice through skin and muscle.

Thirty five living species are included in the Canid family tree. There are three main groups.

1. South American foxes 2. Wolves, including jackals, wolves, coyotes, and dogs 3. Foxes including the red fox and his relatives. The dog that we commonly know is the closest kin to the gray wolf.

There is genetic evidence and fossils that confirm that all dogs are the direct descendants of wolves. Skeletons of the earliest dogs and their wolf cousins are very hard to find differences.

There are around 400 domestic breeds of dogs and they all belong to the same species, Canis familiaris.

A group that can successfully reproduce with one another is known as a species. A sub-group of the species is a breed. This has been made by human interaction. All individuals in a breed can reproduce with each other, but the features of the breed can be altered or lost when one breed is crossed with another.

Fossil records show there are three main groups of dogs and they have been around for many years. Some have become extinct.

Group one came from North America around 40 million years ago. These dogs looked like a mix of a weasel and a fox from fossil evidence. They became extinct around 15 million years ago. They were called Hesperocyon, which means 'western dog'.

Group two were larger and looked similar to hyena's with big jaw muscles and strong teeth. They began around 34 million years ago and became extinct around 2.5 million years ago. They were called borophagines.

Group three called the canines includes the dogs we know today. This group is first seen in fossils from North America around 7 million years ago.

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