Eucyon sp.

Rook, Lorenzo, 2009, The wide ranging genus Eucyon Tedford & Qiu, 1996 (Mammalia, Carnivora, Canidae, Canini) in the Mio-Pliocene of the Old World, Geodiversitas 31 (4), pp. 723-741 : 732-733

? Eucyon sp.

Canis ex gr. lepophagus from Kuruksay – Sotnikova 1989.

LOCALITY. — Kuruksay ( Kazakhstan).

AGE. — Late Pliocene (MN17).

Two mandibular fragments from Kuruksay ( Kazakhstan; MN17) were described by Sotnikova (1989) as Canis ex gr. lepophagus. The material was excavated from the type locality of “ Canis ” kuruksaensis Sotnikova, 1989 . This led Rook (1993) to suggest the inclusion of these mandibles in the latter species. The relationships of these mandibles to the skull of “ Canis ” kuruksaensis (a dog that should be included in the genus Eucyon according to R. H. Tedford [pers. comm. in Spassov & Rook 2007]) are not yet clarified. In the original description ( Sotnikova 1989; description published well before the naming of the genus Eucyon ) the mandibular diagnostic features separating Canis from the later described Eucyon are not discussed. In any case, the material is in a very bad state of preservation and a definite decision regarding their taxonomic status will be a difficult task (Spassov & Rook 2007).

AFRICA

Recognition of the occurrence of the genus Eucyon in the fossil record of the African continent has been fully acknowledged only in very recent years. Rook (1993) reported that the occurrence of different Eucyon species was possibly identifiable also in one latest Miocene and one early Pliocene site in Africa: 1) the latest Miocene of E Quarry at Langebaanweg ( South Africa; Fig. 1 ), from where Hendey (1974, 1978, 1981) described some remains (among which an almost complete cranium and mandibles) as Vulpes sp. and as “gen. et sp. not det. (?aff. Canis brevirostris )”; 2) various sites at Laetoli (early Pliocene, Tanzania; Fig.2 ), from where Barry (1987) referred to as “new genus?, aff. Canis brevirostris ” a number of fragmentary remains.

Rook (1993) revised the material and hypothesized that both Langebaanweg and Laetoli fossil canids could represent the occurrence of the genus Eucyon in Africa (the Langebaanweg form being very primitive). An opinion that was supported by Werdelin & Lewis (2000), at least for the material from Laetoli referred by Barry(1987) to “new genus?, aff. Canis brevirostris ”. As a matter of fact however, a proper taxonomic identification of these fossils needs further work.

A further occurrence of Eucyon in Africa is at the late Pliocene site of Ahl Al Oughlam in Morocco. There Geraads (1997) described a few remains of Canis n. sp., aff. C. aureus Linnaeus, 1758 . The material, whose morphology resembles Eucyon , was recently maintained within the genus Canis by Geraads (2008).

It is only in very recent years that new material has been described from fossil sites in the latest Miocene of Kenya (Kapsomin and Lemudong’o) and early Pliocene of Ethiopia (Aramis).

Figures

FIG. 1. — The latest Miocene Eucyon Tedford & Qiu, 1996 dispersal: A, oldest record of E. davisi (Merriam, 1911) is from Early Hemphillian localities in the western North America (●). The genus quickly expands its record to east in the central and south eastern North America, where it is a common element in late Hemphillian local faunas (□). The late Miocene (MN 12-13 in the European mammal biochronology; ○ locations correspond to time of transcontinental dispersal of the genus, across the Beringia, towards Asia, Europe, and Africa; B, type specimen of E. davisi, right M1-2 in occlusal view (M1 length measures about 10 mm) from Rattlesnake creek, early Hemphillian, Oregon (UCMP545; Earth Sciences Dept., University of Florence); C, D, E. monticinensis (Rook, 1992) left M1 in lingual (C) and occlusal (D) views (M1 length about 17 mm) from Monticino Quarry near Brisighella (BRS27/6; Earth Sciences Dept., University of Florence); E, the figure is completed by a reconstructed scene of a group of adult Eucyon moving eastward in a late Miocene Central Asia grassland scenario. The artistic scene aims to ideally represent the dispersal of the genus Eucyon from North America to the Old World during the latest Miocene.

FIG. 2. — The early and mid-Pliocene Eucyon Tedford & Qiu, 1996 distribution: A, during early and mid-Pliocene times (◇) the genus Eucyon had a wide distribution across Eurasia. The very late record of the genus (○, late Pliocene/middle Villafranchian) seems to be limited to central Asia and to the more arid areas of eastern Eurasia (Turkey, North Africa); B, the typical Pliocene species from Europe E. adoxus (Martin, 1973) from St-Estève (near Perpignan, France; MN 15), cast of skull (approximate length 18 cm) and mandible (reversed) RSS-45 (Basel Naturhistorisches Museum);C, E. davisi (Merriam, 1911) from Hsia Kou (Yushe basin, China; Pliocene),cast of skull (approximate length 15 cm) F:AM-97056 (American Museum of Natural History, New York); D, E. zhoui Tedford & Qiu, 1996 from Chao Chuang (Yushe basin, China; Pliocene), cast of skull (reversed) and mandibular ramus (approximate length of mandibular ramus 10 cm) F:AM-97048 (American Museum of Natural History, New York).