I choose to believe my information, seeing as how I don't know where you've gotten yours from, so here it is...and I quote.
"The modern breeds of domesticated dog belong to the family Canidae along with their wild cousins, the wolves, coyotes, jackals and foxes. They are all flesh-eaters, or carnivores, but unlike the other carnivores such as the cats, which mainly ambush their prey, they instead chase after adn run down their prey. Consequently members of the dog family are characteristically built for speed and endurance. Some species, such as the fox, are solitary hunters, while others, like the wolf, hunt in packs. The wolf type is therefore very sociable.
Dr. L. H. Colbert has traced the ancestry of the dog from fossil remains of various carnivores, going back as far as the transition from Eocene to the Oligocene ages, some 40,000,000 years ago. A small, civetlike carnivorous animal lived during this period which has been given the name MIACIS. Present-day civets are possibly his direct descendants. Later in the Oligocene, two species emerged from MIACES, one a bear-dog or wolverinelike animla from which the present-day bears are believed to have evolved. The other offshoot, known as CYNODICTIS, is thouth to be the grandfather of all the dog family.
CYNODICTIS apparently had partially retractile claws and therefore most probably lived in trees. From this, in the lower Miocene, arose two more evolutionary branches, one giving rise to the present-day hunting dogs of India and Africa. The other CYNODESMUS, which developed into large hyenalike animals, was destined to become extinct in North America. But during the upper Miocene the offshoot of CYNODESMUS evolved, TOMARCTUS, from which the wolf, dog and fox are thought to have evolved.
In spite of the common ancestry of present-day carnivorous mammals, the origin of the domesticated dog is clouded in the unrecorded history of primitive man. Our only recourse is to sift through archeological remains. Careful excavations hae shown that for at least the last 10,000 years man has had dogs as close companions. Examination of the skulls of the animals has revealed that they were indeed dogs and that the only wild animal with comparable dental characteristics is the wolf. Jackals, coyotes, and foxes have much less in common with the dog in terms of skeletal features, even though the jackal and coyote will interbreed with the domesticated dog. The consensus is, then, that the wolf is the closest cousin of the domesticated dog.
Some authorities contend that the dog is directly descended from the wolf, while others believe that the present-day dog is the descendant of wolf crossed with a close relative which was more doglike than wolflike in appearance. This "missing link" may be a dingo or basenjilike ancestor. But when we look at the worldwide distribution o fthe wolf and the regional variations in body size and coat color, it is not difficutl to imagine that thousands of years ago orphaned wolf cubs were raised by primitive man, who selected those with the most stable temerpament and other attributes desirable in an animal that guards the home or other domesticated livestock or assists its master on hunting expeditions.
The complex cycle of the evolution of dog breeds which parallels the evolution and spread of human cultures makes it difficult to go back in time and determine the origins of the many breed types. Mesopotamia, a region of great cultural evolution 2,000 years B.C., was probably the major source of domesticated dogs of various types that were gradually disseminated throughout Asia and Europe years later.
-Understanding Your DOG
Michael W Fox, DVM