Abstract:

The hominin fossils have been found in more than 20 late Middle Pleistocene sites in present China. For many years, these fossils have been classified as archaic Homo sapiens, intermediate between Homo erectus and early modern humans, and the ancestors of modern humans in East Asia. However, such an opinion has never been widely accepted in paleoanthropological community. There have been debates on the evolution and taxonomy of late Middle Pleistocene hominins in China and around the world. Since 21^st century, some noticeable progresses on the late Middle Pleistocene hominin evolution in China have been achieved. The discoveries and studies on the hominin fossils of Penghu, Xuchang, Hualongdong, Xiahe and Harbin greatly enriched the hominin fossil record in China. Studies on the late Middle Pleistocene hominin fossils in China revealed complicated morphological diversities indicating simply classifying all the hominins of this time period into archaic Homo sapiens cannot accurately reflect the evolutionary patterns of Middle Pleistocene hominins in China. According to the studies of the hominin fossils from Xujiayao, Xuchang, Hualongdong, Xiahe and Harbin, some new opinions on the evolutionary pattern and taxonomy of the late Middle Pleistocene hominins in China have been proposed and triggered different understandings.

In this study, with analyzing the morphological diversities of late Middle Pleistocene hominin fossils in China, four types of the diversities were identified. Xuchang and Xujiyao are characterized with huge-sized crania and cranial capacity (1800 mL and 1700 mL respectively) with some Neanderthal features. These features occurred together in Xuchang and Xujiayao crania constitute unique morphological combinations which have not been found in all other contemporaneous hominin fossils. The other types of morphological diversities are characterized with 1) dominant common sharing features of late Middle Pleistocene hominins; 2) mainly primitive features; and 3) mainly derived or modern features. These morphological diversities suggest that not all the late Middle Pleistocene hominins in China contributed the formation of modern humans equally. Regarding the opinions that put some of the hominin fossils into different Homo members or taxa, the authors believe that at the present with no fully understanding these morphological diversities, treating the related late Middle Pleistocene hominin fossils in China with combined or mosaic morphological features as populations of unclear taxonomic status is a proper way.

Key words: Late Middle Pleistocene, archaic Homo sapiens, morphological diversity, taxonomy, evolution