Guy Kilby, age 12, of Surrey, B.C., Canada, for his question:
What were prehistoric wolf ancestors like?
If you saw a Pekingese and a Great Dane for the first time, you might not suspect that both belong to the same animal family. Chances are, the various dogs that live on your street come in a wide variety of shapes and sizes. Paleontologists have traced their family fossils back through 40 million years. Considering the array of modern dogs, we would expect to unearth a wide range of variations in the family tree.
The earliest ancestor of the dogs was a smallish, tree climbing carnivore with a long body and short legs, sharp claws and a very long furry tail. The paleontologists who studied his fossilized remains named him Miacis. He lived some 40 million years ago, when herds of sheep sized horse ancestors roamed in North America. There also were herds of humpless camels, like small graceful gazelles and frisky horse sized rhinos.
As millions of years rolled by, the offspring of those ancestral animals improved to keep pace with the times. The horses ran faster, the rhinos grew bigger. The family tree of Miacis produced two branches of quite different descendants. The ancestor of one b ranch has been named Daphaenus. He was a large, heavy hunter with a huge head, short legs and bushy tail. He is called the bear dog because his descendants gave rise to the bear family. We must count Daphaenus among the dog ancestors because he too descended from the original Miacis.
Meantime, a more dog like branch of the original family developed. His ancestor is named Cynodictus. At first, this branch resembled the slender furry civets that now live in parts of the Old World. However the civets are not related to the dogs. And during the next few million years, the Cynodictus branch separated into several 'quite different strains.
During the 12 million years of the Miocene Period, the canine family was represented by wolfish dogs, foxy dogs and a scavenger somewhat like the modern hyena, though not related. A wild dog named Temnocyon was the ancestor of the large spotted hunting dogs of modern Africa and India.
What were prehistoric for Tuesday, February 5, 1974 In North America, there lived a bull dog type with a huge skull and massive bone crushing jaws. For a time he filled the role of a scavenging hyena and later his line became extinct.
Meantime a canine named Cynodesmus thrived in North America. He was a runner, learning to hunt. Scientists tell us that he was a direct ancestor of the wolves, the foxes and the coyotes. And about 15 million years ago, one branch of his family gave rise to a very dog like type named Tomarctus. Old Tom was a sturdy, wolfish fellow with a long, low body, a thick coat and an extra long bushy tail. Be was the direct ancestor of our wondrous assortment of modern dogs.
Some of his descendants were adopted and domesticated by our early ancestors, more than 10,000 years ago. For a long time it was assumed that these first partly tame dogs came from wild wolves and perhaps jackals. But more recent evidence suggests that our domestic dogs came from a different line, neither wolf nor jackal. Later their wild relatives disappeared. It's nice to know that mankind saved his first and best animal friend from extinction.