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).
If, at this point, you’re wondering where mammals like mustelids, seals, bears, etc. The evolutionary history of the dog family is still not completely resolved (and may never be, as new fossil finds and molecular techniques offer new insights), but the following is a generally accepted hypothesis.
Evolution and Early Distribution Taxonomy North American Red foxes British Red foxes Size Appearance and Colour Samson foxes Distribution Habitat Abundance Ageing and Longevity Mortality and Disability Parasites and Diseases Sexing Activity Dens/Earths and Resting Sites Senses Vision Hearing Smell Touch Territoriality and Home Range Predators Food and Feeding Types of prey consumed Prey switching The influence of age and sex on diet How much food?
Hunting strategies and behaviour Killing to ‘excess’ and the storage of left-overs Breeding Biology Reproductive development The number of breeding vixens Mating and monogamy Gestation, birth and litter size Growth and development of the cubs Behaviour and Social Structure Live and let live: the evolution of group-living With a little help from my friends: ‘helpers’ in fox society Keeping order and knowing your place: the social hierarchy All in the name of fun: fox body language Nightly interactions Communication: something to shout about Interaction with Humans The fox in literature and film The emblematic fox Foxes held in high esteem: gods, devils and worship The fox as a resource: fur, meat and sport The verminous fox: foxes as pests Man’s best friend?
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.
The evolution of carnivorans appears to have been a gradual process that happened in both North America and Eurasia, making it difficult to infer when it all started.
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.
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.
This radiation was probably in response to a vacant niche opening up as the borophagines started to die-out, and not only marked the birth of all the dog species we know today but also heralded the appearance of three modern-day genera in the south-western USA: (true foxes).