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 : 728

Eucyon sp.

LOCALITY. — Khirgis Nur ( Mongolia).

CHRONOLOGIC RANGE. — Latest Miocene.

Until recently, the oldest documentation of the genus Eucyon in Asia was dated to the early Pliocene ( Tedford & Qiu 1996). The Eucyon absence from latest Miocene documentation was representing a sort of “ E. vacuum ” in Asia ( Wang & Tedford 2008: 145), given the latest Miocene occurrence of the genus in North America, Europe ( Rook 1992) and Africa ( Morales et al. 2005; Howell & García 2007).

The occurrence of Eucyon has now been recorded from the latest Miocene of Central Asia, in Mongolia, at Khirgis Nur ( Sotnikova & Rook 2009). The previous claimed occurrence of the genus in China from the Upper Baodean (late Miocene) beds in the Yushe basin reported by Deng (2006: 156) is invalid (X. Wang pers. comm.). Given the outstanding record of the late Miocene of China and especially the Yushe Basin, it may well be that eventually late Miocene records of Eucyon will be found in China, but such an evidence is not available yet.

The new data from Mongolia reveal that the earliest occurrence of the genus in Asia coincides with that in Europe and Africa, suggesting that the disperal of Eucyon from America to the Old World was synchronous. This “ Eucyon datum” had a profound significance for the Old World continental carnivore guild composition and turnover ( Fig. 1 ).

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.