Knowledge of primate evolutionary history from the Late Miocene to the present in East Asia is necessary to develop a tangible conservation strategy for their today and future. This background is especially evident from the distributions of fossil-bearing sites in the Pleistocene and historical records over the past 800 years. They illustrate catarrhines’ early dispersal and radiation routes, paths, and later shrinking trajectories, based on which their future distribution areas can be predicted, providing robust evidence and information for making or amending conservation strategies. The catarrhines (apes and Old-World monkeys) in East Asia are analyzed. Their spread during the Pleistocene from the west to east remarkably involved the three river systems (Yangtze, Yellow, and Pearl) and the coastlines, resulting in broad distributions in the Far East (Taiwan, Korea, and Japan). Their continental taxa significantly suffered reductions from ancient to modern Holocene, leading to a tremendous biodiversity loss in East Asia. These events corresponded to major periodic social upheavals and anthropogenic activities, particularly the Second World War and Civil War in the first half of the last century and the post-war period after 1950 that has involved unparalleled environmental devastation and natural resource depletion. Except for the taxa in Taiwan and Japan, primates, including the catarrhines and strepsirrhines, in East Asia will finally be confined to Southwest China, especially a Convergence-Divergence Center (CDC) that has played a unique role in shielding primates and other animals, as well as the plants since the Later Miocene. Thus, developing a specific conservation priority is critical for the CDC and its adjacent regions to mitigate primate extinction in East Asia.

This study is based on two databases collected from a broad literature review:

1) Primate fossil locations (please see Appendix) discovered in the Late Miocene (11.6 – 5.3 mya), Pliocene (5.3 – 2.58 mya), Early Pleistocene (2.58 – 0.77 may), Middle Pleistocene (0.77– 0.129 mya) and Late Pleistocene (0.129 – 0.0117 mya). However, as the fossil sites of the catarrhines in the Pliocene are very scarce, especially regarding the Pongidae and Hylobatidae (Harrison 2016), the reconstruction of the dispersal scenarios focused on the Pleistocene.  

2) Pongidae was extinct in the Late Pleistocene, so later information in the Holocene comes from historical geographic distributions of the existing Colobinae (from 1304), Cercopithecinae (from 1175), and Hylobatidae (from 1182): a remarkable 800-year period. Such information is from the records of Chinese local governmental historical archives, annals, journals, and books; more details have been given in our previous publications: (Li et al., 2020; Li et al., 2002). Public records categorize catarrhines into four different groups: 1) gibbons, called “Yuan” in Chinese, are characterized by long upper limbs, slim body structure, unique calls, and acrobatic behavior (Zhang, 2015; Zhou and Zhang, 2013). Their records appeared since the Zhou Dynasty (1027-221 BC) in art, mainly in paintings (Geissmann, 2008), and other social services, such as funeral services, being buried with the dead (Vogel, 2018); 2) snub-nosed monkeys (Rhinopithecus) with up-turned nostrils and sturdy body structure; 3) leaf-eating monkeys (Presbytis, Trachypithecus, Pygathrix, and Semnopithecus), showing slender body structure with typical arboreal lifestyle and special folivorous diets; and 4) macaques that are primarily terrestrial and morphologically quite different from the other groups (Li et al., 2020).

Among the four, 1) belongs to the Hylobatidae (gibbons), containing Nomascus (4 species), Hylobates (1 species), and Hoolock (1 species); 2) and 3) are classified as the Colobinae (colobines), including snub-nosed monkeys (Rhinopithecus, five species) and langurs (Trachypithecus, six species; Pygathrix, one species; and Semnopithecus, one species); and 4) is regarded as the Cercopithecinae (Macaca), consisting eight species (Li et al., 2018).