2005 年 21 巻 2 号 p. 121-138
The evolutionary history of cercopithecine monkeys in the Eurasian continent is discussed based on the compiled chronological and geographic data of fossil records from the late Miocene through the middle Pleistocene. Cercopithecines are likely to have originated in northern Africa and appeared in Eurasia as early as the latest Miocene. The fossil records of cercopithecines are rich in Europe and Eastern Asia, where cercopithecines appeared at the latest Miocene. In both areas, respectively, there are three cercopithecine genera reported so far: Macaca, Paradolichopithecus, and Theropithecus in Europe, and Macaca, Procynocephalus, Theropithecus in Eastern Asia. All European fossil macaques are referred to the single species, M. sylvanus or to its close relative, whereas many species are recognized for the Asian macaques. This taxonomic contrast may reflect the geographical differences between the two areas: contrary to the relatively continuous land condition in Europe, Eastern Asia, especially Southeast Asia, has been fractionized into small islands or regions many times due to the eustatic change in sea level, which accelerated speciation of Asian macaques. On the other hand, it is also a debatable issue whether baboons have invaded Eurasia as well as geladas. It has been suggested by a Russian researcher that “Paradolichopithecus” sushkini of the late Pliocene of Kuruk-Say, Tajikistan, is not a macaque but a baboon based on the craniodental morphology (Maschenko, 1994; 2005), which was recently supported by CT (computer tomography) analysis on the structure of the maxillary sinus (Nishimura et al., in prep.). Evolutionary history of cercopithecine monkeys may be more complicated than ever presumed.