According to Forbes, canine fossils from millions of years ago have been discovered by researchers from Brown University and the American Museum of Natural History.

According to their research, the forelimbs of these canines were actually not specialized for running, but did rather had flexibility for grappling, useful for a carnivore. However, the study further showed that during a climate cooling period in the past, dogs evolved predators that relied on stealth and ambush to predators that pursued their prey, similar to the wild coyote and fox.

Researcher Christine Janis comments “It’s reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores. Although this seems logical, it hadn’t been demonstrated before.”

The telltale sign of this evolution was the elbow of the canines. The study indicated that the elbow of dogs were originally similar to those of cats, with front paws that could swivel, which allowed the animal to grab at and wrestle with prey.

“The elbow is a really good proxy for what carnivores are doing with their forelimbs, which tells their entire locomotion repertoire,” Janis also commented..
“There’s no point in doing a dash and a pounce in a forest,” she adds. “They’ll smack into a tree.”

Additionally, these researchers discovered that previous dog species had teeth with greater durability. This is possibly due to the fact that early canines had to tear through skin and flesh, confirming “their skeleton became increasingly modified towards the morphology of extant fast-running predators.”