The large ice sheet that covered most of Canada and the northern fringes of the USA from around 100,000 to 10,000 years ago (during the Wisconsin glaciation) kept the Red foxes in Alaska (the population of which was added to by a second wave of colonisation from Eurasia) separate from those in the southern USA.

and is thought to stem from the now extinct small fox-like , which lived in North America.

During the late Miocene, around 10 mya, something important happened: the third, and for our purposes most important, canid radiation began.

A couple of million years later the dogs started arriving in Eurasia, and the Pliocene (4-5 mya) saw the dogs spread into Africa and South America.

Around six mya, the first wolf-like dog arrived in western Europe.

Briefly, the creature that taxonomists currently think gave rise to modern-day dogs was a medium-sized (about the size of a coyote) grassland predator of North America called that appeared during the late Eocene, some 36 mya.

The caniforms subsequently diverged into three lineages (which we call subfamilies): the Hesperocyoninae (‘western dogs’); the Borophaginae (‘bone-crushing dogs’); and the only one still around, the Caninae, which includes the dogs, wolves, foxes, etc.

According to Wang and Tedford, the first true foxes appeared in North America late in the Miocene (around 9 mya) and were represented by a small Californian species known as , which was found in the Central African country of Chad and dates to the late Miocene (some 7 mya).

Recent work by Louis de Bonis and colleagues at the Université de Poitiers in France has suggested that the foxes and other canids first spread throughout Africa, before invading Europe via a trans-Mediterranean route towards the end of the Miocene.

Nonetheless, taxonomists (those who study how species are related to each other) currently think that the carnivorans evolved from animals called miacids, which were small tree-living mammals that looked similar to modern-day civets.

At some point -- by current thinking, around 42 million years ago (mya), during the mid-Eocene -- it appears that the carnivorans split into the two groups, or suborders, that we recognise as cat-like (Feliformia) and dog-like (Caniformia).

Fox domestication Living with the wild: interacting with wild foxes Interaction with other Species Small and Medium-sized Mammals Livestock Gamebirds Arctic Foxes and other Carnivores Deer Native Animals in Australia Plants and Invertebrates Questions and Answers Evolution and Early Distribution: Dogs and cats are Carnivorans, that is, they’re members of the taxonomic order Carnivora (note this is different to simply being a carnivore, or meat-eater, which is not a taxonomic grouping), which is one of 29 orders within the class Mammalia.