''Xenocyon'' ("strange dog") is an extinct

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

of ''Canis''. The group includes ''Canis'' (''Xenocyon'') ''africanus'', ''Canis'' (''Xenocyon'') ''antonii'' and ''Canis'' (''Xenocyon'') ''falconeri'' that gave rise to ''Canis'' (''Xenocyon'') ''lycanoides''. The hypercarnivorous ''Xenocyon'' gave rise to the modern

dhole The dhole (''Cuon alpinus''; ) is a canid native to Central, South, East and Southeast Asia. Other English names for the species include Asian wild dog, Asiatic wild dog, Indian wild dog, whistling dog, red dog, red wolf, and mountain wolf. It ...

and the

African wild dog The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Ly ...

Taxonomy

''Xenocyon'' is proposed as a subgenus of ''Canis'' named ''Canis'' (''Xenocyon''). One taxonomic authority proposes that as part of this subgenus, the group named ''Canis'' (''Xenocyon'') ex gr. ''falconeri'' (ex gr. meaning "of the group including") would include all of the large hypercarnivorous canids that inhabited the Old World during the Late Pliocene–Early Pleistocene: ''Canis'' (''Xenocyon'') ''africanus'' in Africa, ''Canis'' (''Xenocyon'') ''antonii'' in Asia and ''Canis'' (''Xenocyon'') ''falconeri'' in Europe. Further, these three could be regarded as extreme geographical variations within the one taxon. This group was hypercanivorous, had a large body size that is comparable with the northern populations of the modern

gray wolf The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly ...

(''Canis lupus'') and are characterized by a short neurocranium relative to their skull size. The ancestral condition for canids is to have five toes on their forelimbs, but by the Early Pleistocene this lineage had reduced this to four, which is also a characteristic feature of the modern

(''Lycaon pictus''). The African wild dog cannot be positively identified in the fossil record of eastern Africa until the middle Pleistocene, and identifying the oldest ''Lycaon'' fossil is difficult because these are hard to distinguish from ''Canis'' (''Xenocyon'') ''africanus''. Some authors consider ''Canis'' (''Xenocyon'') ''lycanoides'' as ancestral to the genera '' Lycaon'' and ''

Cuon The dhole (''Cuon alpinus''; ) is a canid native to Central, South, East and Southeast Asia. Other English names for the species include Asian wild dog, Asiatic wild dog, Indian wild dog, whistling dog, red dog, red wolf, and mountain wolf. It ...

''. Therefore, one taxonomic authority has proposed that all of the ''Canis'' (''Xenocyon'') group should be reclassified into the genus ''Lycaon''. This would form three

chronospecies A chronospecies is a species derived from a anagenesis, sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a populatio ...

: ''Lycaon falconeri'' during the Late Pliocene of Eurasia, ''Lycaon lycaonoides'' during the Early Middle Pleistocene of Eurasia and Africa and ''Lycaon pictus'' from the Middle Late Pleistocene to present.

Species

''Canis'' (''Xenocyon'') ''africanus''

The species was originally named ''Canis africanus'' (Pohle 1928) but was later reassigned as ''Canis'' (''Xenocyon'') ''africanus''. It existed during the

Late Pliocene Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

and

Early Pleistocene The Early Pleistocene is an unofficial sub-epoch in the international geologic timescale in chronostratigraphy, being the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently estimated to span the time ...

of Africa.

''Canis'' (''Xenocyon'') ''antonii''

The species was originally named ''Canis antonii'' (Zdansky 1924) but was later reassigned as ''Canis'' (''Xenocyon'') ''antonii''. It existed during the late Pliocene and Early Pleistocene of Asia. The name was applied to Late Pliocene fossils of canids with hypercarnivorous dentition that were found in China at the sites Loc. 33 (Yang Shao Tsun in

Henan Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...

Province), Loc. 64 (

Chihli Zhili, alternately romanized as Chihli, was a northern administrative region of China since the 14th-century that lasted through the Ming dynasty and Qing dynasty until 1911, when the region was dissolved, converted to a province, and renamed ...

Province). and Fan Tsun (

Shansi Shanxi (; ; formerly romanised as Shansi) is a landlocked province of the People's Republic of China and is part of the North China region. The capital and largest city of the province is Taiyuan, while its next most populated prefecture-lev ...

Province). The species was recorded in Europe as ''Canis'' (''Xenocyon'') ''falconeri''.

''Canis'' (''Xenocyon'') ''falconeri''

Upper

Valdarno The Valdarno is the valley of the river Arno, although this name does not apply to the entire river basin. Usage of the term generally excludes Casentino and the valleys formed by major tributaries. Some towns in the area: *Rignano sull'Arno *Fi ...

is the name given to that part of the

Arno The Arno is a river in the Tuscany region of Italy. It is the most important river of central Italy after the Tiber. Source and route The river originates on Monte Falterona in the Casentino area of the Apennines, and initially takes a s ...

valley situated in the provinces of

Florence Florence ( ; it, Firenze ) is a city in Central Italy and the capital city of the Tuscany region. It is the most populated city in Tuscany, with 383,083 inhabitants in 2016, and over 1,520,000 in its metropolitan area.Bilancio demografico an ...

and

Arezzo Arezzo ( , , ) , also ; ett, 𐌀𐌓𐌉𐌕𐌉𐌌, Aritim. is a city and ''comune'' in Italy and the capital of the province of the same name located in Tuscany. Arezzo is about southeast of Florence at an elevation of above sea level. ...

, Italy. The region is bounded by the

Pratomagno The Pratomagno is a mountain range, which has the Arno River on both sides: to the west is the upper Valdarno and to the east is the Casentino. It lies north-west of the city of Arezzo, in Tuscany, Italy Italy ( it, Italia ), officially the ...

mountain range to the north and east and by the Chianti mountains to the south and west. The Upper Valdarno Basin has provided the remains of three fossil canid species dated to the Late

Villafranchian Villafranchian age ( ) is a period of geologic time (3.5–1.0 Ma) spanning the Late Pliocene and Early Pleistocene used more specifically with European Land Mammal Ages. Named by Italian geologist Lorenzo Pareto for a sequence of terrestrial s ...

era of Europe 1.9-1.8 million years ago that arrived with a faunal turnover around that time (

). It is here that the Swiss paleontologist

Charles Immanuel Forsyth Major Charles Immanuel Forsyth Major (15 August 1843, Glasgow – 25 March 1923, Munich) was a Scottish-born, Swiss physician, zoologist and vertebrate palaeontologist. Major was born in Glasgow and studied at Basel and Zurich Universities in Switzerl ...

discovered Falconer's wolf (''Canis falconeri'') (Forsyth Major 1877). The species was later reassigned as ''Canis'' (''Xenocyon'') ''falconeri'', but was later regarded as the European arrival of ''Canis'' (''Xenocyon'') ''antonii''. The species gave rise to ''Canis'' (''Xenocyon'') ''lycanoides''.

''Canis'' (''Xenocyon'') ''lycaonoides''

The species was originally named ''Xenocyon lycaonoides'' (Kretzoi 1938) but was later reassigned as ''Canis'' (''Xenocyon'') ''lycanoides''. Another view is that ''lycaonoides'' and ''falconeri'' should be classified under genus ''Lycaon'', to give the descent of 3 chronospecies: ''L. falconeri'' Late Pliocene of Eurasia → ''L. lycaonoides'' Early Pleistocene and the beginning of the

Middle Pleistocene The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. The ...

of Eurasia and Africa → ''L. pictus'' Middle–Late Pleistocene and now the extant African descendant. The diversity of the wolf-sized species decreased by the end of the Early Pleistocene and into the Middle Pleistocene of Europe and Asia. These wolves include the large hypercarnivorous ''Canis'' (''Xenocyon'') ''lycaonoides'' that was comparable in size with the modern gray wolf (''C. lupus'') northern populations and the small Mosbach wolf ('' C. mosbachensis'') that is comparable in size to the modern

Indian wolf The Indian wolf (''Canis lupus pallipes'') is a subspecies of gray wolf that ranges from Southwest Asia to the Indian Subcontinent. It is intermediate in size between the Himalayan wolf and the Arabian wolf, and lacks the former's luxuriant wint ...

(''C. l. pallipes''). Both types of wolves could be found existing from England and Greece across Europe to the high latitudes of Siberia through to Transbaikalia, Tajikistan, Mongolia, and China. The true gray wolves did not make an appearance until the end of the Middle Pleistocene, 500-300 thousand years ago. Fossil evidence to dated 1.8 million years ago from

Dmanisi Dmanisi ( ka, დმანისი, tr, , az, Başkeçid) is a town and archaeological site in the Kvemo Kartli region of Georgia approximately 93 km southwest of the nation’s capital Tbilisi in the river valley of Mashavera. The hominin ...

, Georgia in the southern Caucasus suggests that they were cooperative hunters which cared for their sick, injured and disabled pack members similar to the modern grey wolf. It preyed on

antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

elephant Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae an ...

calves,

aurochs The aurochs (''Bos primigenius'') ( or ) is an extinct cattle species, considered to be the wild ancestor of modern domestic cattle. With a shoulder height of up to in bulls and in cows, it was one of the largest herbivores in the Holocen ...

baboon Baboons are primates comprising the genus ''Papio'', one of the 23 genera of Old World monkeys. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow baboon, the Kinda baboon and the chacma ba ...

wild horse The wild horse (''Equus ferus'') is a species of the genus ''Equus'', which includes as subspecies the modern domesticated horse (''Equus ferus caballus'') as well as the endangered Przewalski's horse (''Equus ferus przewalskii''). The Europea ...

s and possibly

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s. It was probably the ancestor of the

(''Lycaon pictus'') and possibly the

(''Cuon alpinus'') of southeastern Asia, the extinct

Sardinian dhole The Sardinian dhole (''Cynotherium sardous'') is an extinct insular canid which was endemic to what is now the Mediterranean islands of Sardinia (Italy) and Corsica (France), which were joined for much of the Pleistocene. It went extinct when h ...

(''Cynotherium sardous'') and perhaps two extinct Javanese dogs (Merriam's dog (''

Megacyon merriami ''Megacyon merriami'', or Merriam's dog, was a prehistoric canid that lived in the early/middle Pleistocene (about 800-300 thousand years ago). Its fossilized remains have been found on the island of Java. Its scientific name means "Merriam's lar ...

'') and the Trinil dog (''

Mececyon trinilensis ''Mececyon trinilensis'', the Trinil dog, is an extinct canid species that lived in Indonesia during the Pleistocene. Description The body size of ''Mececyon trinilensis'' been estimated to be about 22 kg. This size is the result of insul ...

'')). Just before the appearance of the

dire wolf The dire wolf (''Aenocyon dirus'' ) is an extinct canine. It is one of the most famous prehistoric carnivores in North America, along with its extinct competitor ''Smilodon''. The dire wolf lived in the Americas and eastern Asia during the Lat ...

(''Aenocyon dirus''), North America was invaded by the genus ''Xenocyon'', which was as large as ''A. dirus'' and more hypercarnivorous. The fossil record shows them as rare and it is assumed that they could not compete with the newly derived ''A. dirus''. These have been ascribed to ''Xenocyon lycaonoides'', with ''Xenocyon texanus'' from as far south as Texas as its

taxonomic synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

References

{{Taxonbar, from=Q19692941 Canis Prehistoric canines Pleistocene carnivorans Pleistocene mammals of Africa Fossil taxa described in 1938 Animal subgenera