The first members of the dog family Canidae appeared 40 million years ago, of which only its subfamily the Caninae survives today in the form of the wolf-like and fox-like canines. The carnivoran ancestors of the dog-like caniforms and the cat-like feliforms began their separate evolutionary paths just after the end of the dinosaurs.
Today, not all carnivorans are carnivores, such as the insect-eating Aardwolf. This dental arrangement has been modified by adaptation over the past 60 million years for diets composed of meat, for crushing vegetation, or for the loss of the carnassial function altogether as in seals, sea lions, and walruses. Carnivorans possess a common arrangement of teeth called carnassials, in which the first lower molar and the last upper premolar possess blade-like enamel crowns that act similar to a pair of shears for cutting meat. The name carnivoran is given to a member of the order Carnivora. The Cretaceous–Paleogene extinction event occurred 65 million years ago and brought an end to the dinosaurs and the appearance of the first carnivorans. Location of a dog's carnassials the inside of the 4th upper premolar aligns with the outside of the 1st lower molar, working like scissor blades In 2019, a workshop hosted by the IUCN/Species Survival Commission's Canid Specialist Group considered the dingo and the New Guinea singing dog to be feral Canis familiaris and therefore did not assess them for the IUCN Red List of Threatened Species. Mammalogists have noted the inclusion of familiaris and dingo together under the "domestic dog" clade with some debating it. Wozencraft referred to the mtDNA study as one of the guides informing his decision. Wozencraft included hallstromi (the New Guinea singing dog) as another name ( junior synonym) for the dingo. Christopher Wozencraft listed under the wolf Canis lupus its wild subspecies and proposed two additional subspecies, which formed the domestic dog clade: familiaris, as named by Linneaus in 1758 and, dingo named by Meyer in 1793. In the third edition of Mammal Species of the World published in 2005, the mammalogist W. In 1999, a study of mitochondrial DNA (mtDNA) indicated that the domestic dog may have originated from the grey wolf, with the dingo and New Guinea singing dog breeds having developed at a time when human communities were more isolated from each other. Linnaeus considered the dog to be a separate species from the wolf because of its upturning tail ( cauda recurvata), which is not found in any other canid. He classified the domestic dog as Canis familiaris and, on the next page, classified the grey wolf as Canis lupus. Canis is the Latin word meaning "dog," and under this genus, he listed the domestic dog, the grey wolf, and the golden jackal. In 1758, the Swedish botanist and zoologist Carl Linnaeus published in his Systema Naturae, the two-word naming of species ( binomial nomenclature). This influence on human society has given them the sobriquet of " man's best friend."įurther information: Canis lupus dingo § Taxonomic debate – the domestic dog, dingo, and New Guinea singing dog They perform many roles for humans, such as hunting, herding, pulling loads, protection, assisting police and the military, companionship, therapy, and aiding disabled people. Dog breeds vary widely in shape, size, and color.
The dog has been selectively bred over millennia for various behaviors, sensory capabilities, and physical attributes. Over the millennia, dogs became uniquely adapted to human behavior, and the human-canine bond has been a topic of frequent study. ĭue to their long association with humans, dogs have expanded to a large number of domestic individuals and gained the ability to thrive on a starch-rich diet that would be inadequate for other canids. The dog was the first species to be domesticated, by hunter–gatherers over 15,000 years ago, before the development of agriculture. The dog derived from an ancient, extinct wolf, and the modern grey wolf is the dog's nearest living relative. The dog or domestic dog, ( Canis familiaris or Canis lupus familiaris ) is a domesticated descendant of the wolf which is characterized by an upturning tail.