Over a long period of time now, a dog has always been regarded to as the best friend of a man among all the pets kept in the homes. A dog is one of those animals that are more of assets than liabilities to man. Anyone who has a dog in the homestead feels more secure at night than he who doesn’t have one. The dog is regarded as the earliest domestic animal that has been living with man. The history of dog is as old as that of evolution of elephants where, small inoffensive species give rise to others over a cause of decades of million years. Dogs have only been domesticated for a period of 10000 years but the evolution of dog goes back to more than 50 million year.
The earliest carnivore genus was known as tormarctus, an earliest Bone crashing carnivore in which evolved to many species over a period of millions of year. Then there was cimolestes which lived high in trees, they lived for a period of75 millions year ago. This was followed by another ancestry of carnivorous known as the micas which lived form 55-10 million years ago. Every carnivorous animal can trace its origin from miacis. Then there was the mammal carnivorous known as canids.
Modern dogs have evolved from a line of carnivorous mammal known as canids. Which lived about 6 million years ago. It lived along side with other family of dog like the ictitherium(prehistoric hyenas) , the noteworthy breed of canids known as the sarkastodon ,which behaved like wolf and like the grizzly bear.Therewas also the hersperoccyon the first canide.lived 40 million years ago. In the family of western dog, it is also represented in the fossil records, it was one of the common mammals in the North America prehistoric, it was the size of a fox. The other group of early canid known as the borophagus or the born –crashing which it had powerful jaws .this lead to the first true dogs where the leptocyon, after the hersperocyon,which was small .they lived with eucyon, which lived in the time Eurasia and south America. They also lived with another families like of dog, the dire wolf the amphicyon (the bear dog) which later extinct, the cynodicts (thought to be the first true dog), the epicyon (where prehistorically dog which were build more like the cats).
The hespereocyon is referred to as the early ancestor of the today’s modern dog it lived for a period of 40-34 million years it eat meet it had long sleek body with short legs and years like the modern dog this is believed to be the ancestor of modern dog.