Canids

The Canidae (′kanə′dē, ) family is a part of the order Carnivora within the mammals (Class Mammalia). Members of the family are called canids and include dogs, wolves, foxes, coyotes, dingoes, jackals, and lycaons. The Canidae family is divided into the "true dogs" (or canines) of the tribe Canini and the "foxes" of the tribe Vulpini. The two species of the basal Caninae are more primitive and don't fit into either tribe. Any member of this family can be referred to generally as a canid.

Classification
Note that the subdivision of Canidae into "foxes" and "true dogs" may not be in accordance with the actual relations, and that the taxonomic classification of several canines is disputed. Recent DNA analysis has shown, however, that Canini (dogs) and Vulpini (foxes) are valid clades, which exclude two genera: Nyctereutes and Otocyon. These are basal canids and are not closely related to either vulpines or canines. (Some evidence also suggests the same for Urocyon.)

Speothos and Chrysocyon are primitive members of Canini, but might be placed in their own clade. Cuon and Lycaon may in fact belong in Canis, and there is evidence that Alopex and Fennecus are not valid clades, but are both part of Vulpes.

The Domestic Dog is listed by some authorities as Canis familiaris and others (including the Smithsonian Institution and the American Society of Mammalogists) as a subspecies of the Gray Wolf (i.e., Canis lupus familiaris); the Red Wolf, Eastern Canadian Wolf, and Indian Wolf may or may not be full species; and the Dingo is variously classified as Canis dingo, Canis lupus dingo, Canis familiaris dingo and Canis lupus familiaris dingo.

Eocene epoch
Miacids evolved into the Canidae family about 40 million years ago in the late Eocene to early Oligocene. Wolves, foxes, coyotes, jackals and eventually dogs all evolved from the Canidae family. The Canidae family evolved into three subfamilies: Hesperocyoninae (~39.74-15 Mya), Borophaginae (~36-2 Mya), and the Caninae lineage that led to present-day canids, including wolves, foxes, coyotes, jackals, and domestic dogs.

Oligocene epoch
The earliest branch of the Canidae was the Hesperocyoninae lineage, which led to the coyote-sized Mesocyon of the Oligocene (38-24 Mya). These early canids probably evolved for fast pursuit of prey in a grassland habitat, and resembled modern civets in appearance. Hesperocyonine dogs became extinct except for the Nothocyon and Leptocyon branches. These branches lead to the borophagine and canine radiations.

Tomarctus, a wolf/dog-like carnivore, was a borophagine that roamed North America some 10 Mya. Cynodictis, also a borophagine, emerged about 20 Mya in the Oligocene and also resembled the modern dog. Its fifth toe was reduced in size, an intimation of the latter development of the dewclaw. The fox-like Leptocyon was a descendant that branched off from the Caninae lineage. ..

Miocene epoch
Around 9-10 Mya during the Late Miocene, Canis, Urocyon, and Vulpes genuses expand from southwestern North America. This is the point where canine radiation begins. The success of the these canines is the development of lower carnassials that are capable of both mastication and shearing. Around 8 Mya, Berengia offers the canines a way to enter Eurasia.

Early Pliocene
During the Pliocene around (4-5 Mya) Canis lepophagus appears in North America. This dog is small with some being coyote-like. Others are wolf-like in characteristics. It is theorized that Canis latrans (coyote) descended from Canis lepophagus. Around 1.5 to 1.8 Mya, a variety of wolves are now in Europe. Also, the North American wolf line appears with Canis edwardii as clearly identifiable as a wolf. Canis rufus, a red wolf canine appears and possibly a direct descendent of Canis edwardii.

Middle Pliocene
Around 0.8 Mya Canis ambrusteri, emerges in North America. A large wolf, it is found all over the continent. It is thought that this species went to South America where it becomes the ancestor of the Canis dirus or Dire wolf.

Late Pliocene
At 0.3 Mya Canus lupus (Gray wolf) has fully developed and has spread throughout Europe and northern Asia. Berengia offers a way to North America. At around 100,000 years ago, the Dire wolf, some of the largest members of the dog family, appears from southern Canada to South America and coast to coast. The Dire wolf shares its habitat with the Gray wolf. Around 8000 years ago the Dire wolf becomes extinct.

Characteristics
Wild canids are found on every continent, except Antarctica, and inhabit a wide range of different habitats, including deserts, mountains, forests, and grassland. They vary in size from the fennec fox at 24 cm in length, to the gray wolf, which may be up to 200 cm long, and can weigh up to 80 kg.

With the sole living exception of the bush dog, canids have relatively long legs and lithe bodies, adapted for chasing prey. All canids are digitigrade, meaning that they walk on their toes. They possess bushy tails, non-retractile claws, and a dewclaw on the front feet. They possess a baculum, which helps to create a copulatory tie during mating, locking the animals together for up to an hour. Young canids are born blind, with their eyes opening a few weeks after birth.

Many species live and hunt in packs, and have complex social lives. They are generally highly adaptable, and there may be considerable variation in habits even within a single species.

Dentition
Most canids have 42 teeth, with a dental formula of: As in other members of the carnivora, the upper fourth premolar and lower first molar are adapted as carnassial teeth for slicing flesh. The molar teeth are strong in most species, allowing the animals to crack open bone to reach the marrow. The deciduous or baby teeth formula in canids is 3 1 3; molars are completely absent.

Species and taxonomy
FAMILY CANIDAE

Subfamily: Caninae
 * True dogs - Tribe Canini
 * Genus Canis
 * Side-striped Jackal, Canis adustus
 * Golden Jackal, Canis aureus
 * Himalayan Wolf, Canis himalayaensis (species status not official classified!)
 * Indian Wolf, Canis indica or Canis pallipes (species status not official classified!)
 * Coyote, Canis latrans (also called Prairie Wolf)
 * Gray Wolf, Canis lupus (2.723 Ma to present)
 * Domestic Dog, Canis lupus familiaris
 * Dingo, most often classified as Canis lupus dingo
 * New Guinea Singing Dog, Canis lupus hallstromi
 * many other proposed subspecies
 * Red Wolf, Canis rufus (hybrid?) (3 Ma to present)
 * Eastern Canadian Red Wolf, Canis rufus lycaon (subspecies status disputed)
 * Black-backed Jackal, Canis mesomelas
 * Ethiopian Wolf, Canis simensis (also called Abyssinian Wolf, Simien Fox and Simien Jackal)
 * Genus Cynotherium †
 * Sardinian Dhole, Cynotherium sardous †
 * Genus Cuon
 * Dhole, Cuon alpinus or Canis alpinus (also called Asian Wild Dog)
 * Genus Lycaon
 * African Wild Dog, Lycaon pictus (also called African Hunting Dog)
 * Genus Atelocynus
 * Short-eared Dog, Atelocynus microtis
 * Genus Cerdocyon
 * Crab-eating Fox, Cerdocyon thous
 * Genus Dasycyon † ?
 * Hagenbeck Wolf, Dasycyon hagenbecki † ?
 * Genus Dusicyon †
 * Falkland Island Fox, Dusicyon australis †
 * Genus Pseudalopex
 * Culpeo, Pseudalopex culpaeus
 * Darwin's Fox, Pseudalopex fulvipes
 * Argentine Grey Fox, Pseudalopex griseus
 * Pampas Fox, Pseudalopex gymnocercus
 * Sechura Fox, Pseudalopex sechurae
 * Hoary Fox, Pseudalopex vetulus
 * Genus Chrysocyon
 * Maned Wolf, Chrysocyon brachyurus
 * Genus Speothos
 * Bush Dog, Speothos venaticus


 * True foxes - Tribe Vulpini
 * Genus Alopex
 * Arctic Fox, Alopex lagopus
 * Genus Vulpes
 * Red Fox, Vulpes vulpes (1 Ma to present)
 * Swift Fox, Vulpes velox
 * Kit Fox, Vulpes macrotis
 * Corsac Fox (or Steppe Fox), Vulpes corsac
 * Cape Fox, Vulpes chama
 * Pale Fox, Vulpes pallida
 * Bengal Fox, Vulpes bengalensis
 * Tibetan Fox, Vulpes ferrilata
 * Blanford's Fox, Vulpes cana
 * Rüppell's Fox, Vulpes rueppelli
 * Fennec, Vulpes zerda
 * Genus Urocyon (2 Ma to present)
 * Gray Fox, Urocyon cinereoargenteus
 * Island Fox, Urocyon littoralis
 * Cozumel Fox, Urocyon sp.


 * Basal Caninae
 * Genus Otocyon (present)
 * Bat-eared Fox, Otocyon megalotis (propably a vulpine close to Urocyon)
 * Genus Nyctereutes
 * Raccoon Dog, Nyctereutes procyonoides (propably a canine related to Speothos and perhaps Chrysocyon)

Fossil Canidae
Classification of Hesperocyoninae from Wang (1994). Classification of Borophaginae from Wang et al. (1999).

Prehistoric Caninae
 * Canini
 * Genus Canis
 * Dire Wolf, Canis dirus (1 Ma †)
 * Canis arnensis (3.4 Ma, †)
 * Canis (Eucyon) cipio (8.2 Ma †, probably first species of Canis genus)
 * Canis etruscus (3.4 Ma †)
 * Canis falconeri (2.6 Ma †)
 * Canis mosbachensis (0.787 Ma †)
 * Canis lepophagus (4-5 Ma †)
 * Canis donnezani (4.0-3.1 Ma †, probably ancestor of wolves)
 * Canis edwardii (1.8 Ma †, first species of wolf in North America)
 * Canis gezi †
 * Canis nehringi †
 * Canis ameghinoi  †
 * Canis michauxi  †
 * Canis adoxus  †
 * Canis cautleyi  †
 * Canis ambrusteri  (0.8 Ma †)
 * Genus Theriodictis (1.8 Ma †)
 * Theriodictis platensis (1.8 Ma †)
 * Theriodictis tarijensis (1.8 Ma †)
 * Theriodictis (Canis) proplatensis (2.1 Ma † )
 * Genus Protocyon †
 * Protocyon orcesi †
 * Protocyon scagliarum †
 * Protocyon troglodytes †
 * Genus Dusicyon †
 * Dusicyon avus †
 * Genus Cerdocyon
 * Cerdocyon avius †
 * Cerdocyon ensenadensis †
 * Genus Speothos
 * Speothos pacivorus †
 * Genus Nurocyon
 * Nurocyon chonokhariensis †


 * Vulpini
 * Genus Vulpes (7 Ma to present)
 * Vulpes alopecoides (2.6 Ma †)
 * Vulpes cf. alopecoides (2.6 Ma †)
 * Vulpes cf. vulpes (0.1275 Ma †)
 * Vulpes galaticus (4.2 Ma †)
 * Vulpes riffautae (7 Ma †)
 * Basal Canids
 * Genus Nyctereutes (7.1 Ma to present)
 * Nyctereutes cf. donnezani (7.1 Ma †)
 * Nyctereutes cf. megamastoides (3.158 Ma †)
 * Nyctereutes donnezani (3.4 Ma †)
 * Nyctereutes megamostoides (2.6 Ma †)
 * Nyctereutes sinensis (3.4 Ma †)


 * First Caninae
 * Genus Eucyon (8 Ma †)
 * Eucyon davisi (8.3 Ma †, probably ancestor of Canis)
 * Eucyon minor (8 Ma †)
 * Eucyon zhoui (8 Ma †)
 * Eucyon monticinensis(8 Ma †)
 * Eucyon odessanus †
 * Genus Leptocyon (24-16 Ma †)
 * Leptocyon vafer (16 Ma)
 * Leptocyon vulpinus (24 Ma)

Borophaginae : † (Ma = million years ago)
 * Genus Aelurodon (16-12 Ma)
 * Aelurodon asthenostylus (16 Ma)
 * Aelurodon ferox (15 Ma)
 * Aelurodon mcgrewi (15 Ma)
 * Aelurodon montanensis (15 Ma)
 * Aelurodon stirtoni (13 Ma)
 * Aelurodon taxoides (12 Ma)
 * Genus Archaeocyon (32-24 Ma)
 * Archaeocyon leptodus (32-24 Ma)
 * Archaeocyon pavidus (32-28 Ma)
 * Archaeocyon falkenbachi (25-24 Ma)
 * Genus Borophagus (12-5 Ma)
 * Borophagu dividersidens (5 Ma)
 * Borophagus hilli (6 Ma)
 * Borophagus hittoralis (12 Ma)
 * Borophagus orc (9 Ma)
 * Borophagus parvus (7 Ma)
 * Borophagus pugnator (9 Ma)
 * Borophagus secundus (9 Ma)
 * Genus Cynarctoides (30-18 Ma)
 * Cynarctoides acridens (24 Ma)
 * Cynarctoides emryi (21 Ma)
 * Cynarctoides gawnae (18 Ma)
 * Cynarctoides harlowi (21 Ma)
 * Cynarctoides lemur (30 Ma)
 * Cynarctoides luskensis (21 Ma)
 * Cynarctoides roii (30 Ma)
 * Genus Cynarctus (16-12 Ma)
 * Cynarctus crucidens (12 Ma)
 * Cynarctus galushai (16 Ma)
 * Cynarctus saxatilis (15 Ma)
 * Cynarctus voorhiesi (13 Ma)
 * Genus Desmocyon (24-19 Ma)
 * Desmocyon matthewi (19 Ma)
 * Desmocyon thompsoni (24 Ma)
 * Genus Epicyon (12-10 Ma)
 * Epicyon haydeni (10 Ma)
 * Epicyon saevus (12 Ma)
 * Epicyon aelurodontoides (10.3-4.9 Ma)
 * Genus Eulopocyon (18-16 Ma)
 * Eulopocyon brachygnathus (16 Ma)
 * Eulopocyon spissidens (18 Ma)
 * Genus Metatomarctus (19-16 Ma)
 * Metatomarctus canavus (19 Ma)
 * Metatomarctus sp. A (16 Ma)
 * Metatomarctus sp. B (16 Ma)
 * Genus Microtomarctus (18 Ma)
 * Microtomarctus conferta (18 Ma)
 * Genus Osteoborus (8 Ma)
 * Osteoborus cynoides
 * Genus Otarocyon (34-30 Ma)
 * Otarocyon cooki (30 Ma)
 * Otarocyon macdonaldi (34 Ma)
 * Genus Oxetocyon (32 Ma)
 * Oxetocyon cuspidatus' (32 Ma)
 * Genus Paracynarctus (19-16 Ma)
 * Paracynarctus kelloggi (19 Ma)
 * Paracynarctus sinclairi (16 Ma)
 * Genus Phlaocyon (30-19 Ma)
 * Phlaocyon annectens (22 Ma)
 * Phlaocyon latidens (30 Ma)
 * Phlaocyon leucosteus (22 Ma)
 * Phlaocyon marslandensis (19 Ma)
 * Phlaocyon minor (30 Ma)
 * Phlaocyon yakolai (19 Ma)
 * Genus Protepicyon (16 Ma)
 * Protepicyon raki (16 Ma)
 * Genus Psalidocyon (16 Ma)
 * Psalidocyon marianae (16 Ma)
 * Genus Rhizocyon (30 Ma)
 * Rhizocyon oregonensis (30 Ma)
 * Genus Tephrocyon (16 Ma)
 * Tephrocyon rurestris (16 Ma)
 * Genus Paratomarctus (16-13 Ma)
 * Paratomarctus euthos (13 Ma)
 * Paratomarctus temerarius (16 Ma)
 * Genus Protomarctus (18 Ma)
 * Protomarctus optatus (18 Ma)
 * Genus Tomarctus (16 Ma)
 * Tomarctus brevirostris (16 Ma)
 * Tomarctus hippophaga (16 Ma)

Hesperocyoninae : † (Ma = million years ago)
 * Genus Cynodesmus (32-29 Ma)
 * Cynodesmus martini (29 Ma)
 * Cynodesmus thooides (32 Ma)
 * ?Genus Caedocyon
 * Caedocyon tedfordi
 * Genus Ectopocynus (32-19 Ma)
 * Ectopocynus antiquus (32 Ma)
 * Ectopocynus intermedius (29 Ma)
 * Ectopocynus siplicidens (19 Ma)
 * Genus Enhydrocyon (29-25 Ma)
 * Enhydrocyon basilatus (25 Ma)
 * Enhydrocyon crassidens (25 Ma)
 * Enhydrocyon pahinsintewkpa (29 Ma)
 * Enhydrocyon stenocephalus (29 Ma)
 * Genus Hesperocyon (39.74-34 Ma)
 * Hesperocyon colordensis
 * Hesperocyon gregarius (37 Ma)
 * Genus Mesocyon (34-29 Ma)
 * Mesocyon brachyops (29 Ma)
 * Mesocyon coryphaeus (29 Ma)
 * Mesocyn temnodon
 * Genus Osbornodon (32-18 Ma)
 * Osbornodon fricki (18 Ma)
 * Osbornodon iamonensis (21 Ma)
 * Osbornodon renjiei (33 Ma)
 * Osbornodon sesnoni (32 Ma)
 * Genus Paraenhydrocyon (30-25 Ma)
 * Paraenhydrocyon josephi (30 Ma)
 * Paraenhydrocyon robustus (25 Ma)
 * Paraenhydrocyon wallovianus (26 Ma)
 * Genus Philotrox (29 Ma)
 * Philotrox condoni (29 Ma)
 * Genus Prohespercyon (36 Ma)
 * Prohespercyon wilsoni (36 Ma)
 * Genus Sunkahetanka (29 Ma)
 * Sunkahetanka geringensis (29 Ma)