Eucyon

Eucyon Temporal range: Late Miocene–Late Pliocene, 10.3–3.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil skeleton of Eucyon davisi
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Canidae
Subfamily:	Caninae
Genus:	†Eucyon Tedford and Qiu (1996)[1]
Type species
†Eucyon davisi (Merriam, 1911) [originally Canis]
Species
†E. davisi †E. debonisi †E. ferox †E. intrepidus †E. khoikhoi †E. kuta †E. marinae †E. minor †E. monticinensis †E. skinneri †E. wokari †E. zhoui

Eucyon (Greek: εὖ eu: good, true; κῠ́ων cyon: dog) is an extinct genus of medium omnivorous coyote-like canid that first appeared in the Western United States during the late Middle Miocene 10 million years ago. It was the size of a jackal and weighed around 15kg. It was one of the few North American mammals which invaded Eurasia about 6 million years ago, followed by the genus going extinct 3 million years ago. This genus is proposed to have given rise to genus Canis 6 million years ago.[2]: p56–58 

Taxonomy

Eucyon was named by Tedford and Qiu in 1996.[1] Phyletically it stood between Canis and the South American canines that would follow it.[2]: p56  In 2009, Tedford revised its diagnosis and described two of its species, E. skinneri and E. davisi,[3]: 89  which was originally named Canis davisi by Merriam in 1911.[4][3]: 89  Numerous species were previously described as Canis, including Eucyon ferox.[5]

Eucyon davisi

The jackal-sized Eucyon existed in North America from 10 million YBP until the Early Pliocene.[6] Wang and Tedford proposed that the genus Canis was the descendant of the coyote-like Eucyon davisi, remains of which first appeared in the Miocene (6 million YBP) in the southwestern U.S. and Mexico. By the Pliocene (5 million YBP), the larger Canis lepophagus appeared in the same region and by the Early Pleistocene (1 million YBP) Canis latrans (the coyote) was in existence. They proposed that the progression from Eucyon davisi to C. lepophagus to the coyote was linear evolution.[2]: p58 

Eucyon khoikhoi

The recent discovery of the 5 million years old E. khoikhoi supports the proposed radiation of the genus Eucyon, with the oldest E. ferox in North America, to E. davisi in North America then to China, to E. debonisi in Western Europe, to E. khoikhoi in Africa.[7]

Description

A medium canid - it is the size of a jackal, weighing around 15 kg (33 lb).[2]: p56 

Fossil distribution

The fossil remains are found in the Rio Grande, Texas to western Oregon and Washington's Ringold Formation,[8] as well as northern Nebraska, along with Greece, Ethiopia, Mongolia and many other locations across the Old World.[9]

References

1. R. H. Tedford and Z. Qiu. 1996. A new canid genus from the Pliocene of Yushe, Shanxi Province. Vertebrata PalAsiatica (Gujizhui Dongwu Xuebao) 34(#1):27-40
2. Wang, Xiaoming; Tedford, Richard H. (2008). Dogs: Their Fossil Relatives and Evolutionary History. Columbia University Press, New York. pp. 1–232. ISBN 978-0-231-13529-0.
3. Tedford, Richard H.; Wang, Xiaoming; Taylor, Beryl E. (2009). "Phylogenetic Systematics of the North American Fossil Caninae (Carnivora: Canidae)" (PDF). Bulletin of the American Museum of Natural History. 325: 1–218. doi:10.1206/574.1. S2CID 83594819.
4. Merriam, J.C. 1911. Tertiary mammal beds of Virgin Valley and Thousand Creek in northwestern Nevada. Part 2. Vertebrate faunas. Bulletin of the Department of Geology of the University of California 11: 199–304.
5. Saverio Bartolini Lucenti; Lorenzo Rook (2020). ""Canis" ferox revisited: diet ecomorphology of some long gone (Late Miocene and Pliocene) fossil dogs". Journal of Mammalian Evolution. 28 (2): 285–306. doi:10.1007/s10914-020-09500-1. S2CID 218694252.
6. Fossilworks website Eucyon davisi
7. Valenciano, Alberto; Morales, Jorge; Govender, Romala (February 2022). "Eucyon khoikhoi sp. nov. (Carnivora: Canidae) from Langebaanweg 'E' Quarry (early Pliocene, South Africa): the most complete African canini from the Mio-Pliocene". Zoological Journal of the Linnean Society. 194 (2): 366–394. doi:10.1093/zoolinnean/zlab022.
8. Gustafson, Eric Paul (2015). An Early Pliocene North American Deer: Bretzia pseudalces, Its Osteology, Biology, and Place in Cervid History (Thesis). University of Oregon. S2CID 83622137.
9. Rook, Lorenzo (December 2009). "The wide ranging genus Eucyon Tedford & Qiu, 1996 (Mammalia, Carnivora, Canidae, Canini) in the Mio-Pliocene of the Old World". Geodiversitas. 31 (4): 723–741. doi:10.5252/g2009n4a723. S2CID 130345058.