最近在广西崇左木榄山智人洞发现了距今约11万年的早期现代人下颌骨及大量伴生的哺乳动物化石,这是迄今在东亚地区发现的时代最早的早期现代人.本文系统记述了该动物群中的长鼻类化石——较原始的江南象(Elephas kiangnanensis)与初现位的亚洲象(Elephas maximus).智人洞的长鼻类缺失我国南方更新世的典型种类中华乳齿象(Sinomastodon)和剑齿象(Stegodon);智人洞的动物群性质截然不同于华南早更新世的巨猿-中华乳齿象动物群(Gigantopithecus-Sinomastodon fauna)和中更新世的大熊猫-剑齿象动物群(Ailuropoda-Stegodon fauna),是晚更新世亚洲象动物群(Asian elephant fauna)的早期代表.智人洞动物群中缺失大熊猫、剑齿象和竹鼠等华南常见的森林型动物,很可能反映了江南象向亚洲象的一个过渡事件,该事件与早期现代人的起源很可能有一定的耦合关系;此外,动物群中林灌和草地型动物所占比例明显增加,又反映当时可能是森林退缩、林灌和草地扩大的生态环境,对应于相对干旱的气候.%One of the hottest scientific issues in paleoanthropology currently focuses on the origin of modern humans and much more attention is paid to the fossil hominin records of the early Late Pleistocene because it is a critical time for the radiations of modern humans.Recently,the fragmentary human remains (an anterior mandible and two molars) and abundant coexisting fossil mammals were unearthed from the Zhiren Cave (22°17′13.6″N,107°30′45.1″E) of Mulan Mountain,Chongzuo,Guangxi of Southern China.The human remains are securely dated by U-series on overlying flowstones and associated faunal analysis to the initial Late Pleistocene,ca.110ka.As such,they are the oldest modern human fossils in East Asia and predate by ＞60,000 years the oldest previously known modern human remains in the region.A large variety and amount of mammalian fossils were collected from the Zhiren Cave after two times of trial and systematic excavations.The Zhiren fauna is composed of 55 species (21 large mammals and 34 small mammals).In this study the proboscidean remains from this site are systematically described as Elephas kiangnanensis and first occurring Elephas maixmus based on the dental morphology,such as plate number,lamellar frequency and enamel thickness.Recent studies reveal that three turnovers occurred in the proboscidean radiations during Quaternary in Southern China.The genus,Sinomastodon was once prevalent during the Early Pleistocene,and became one of the typical members of the Gigantopithecus-Sinomastodon fauna.It became extinct at the end of the Early Pleistocene,and was replaced by Stegodon orientalis,a main member of the Ailuropoda-Stegodon fauna (s.s.) during the Middle Pleistocene.The appearance of Elaphas kiangnanensis until the late Middle Pleistocene changed the features of the Ailuropoda-Stegodon fauna,and Elaphas maximus gradually became dominant during the Late Pleistocene.Due to the absence of the typical Early or Middle Pleistocene members of Southern China,such as Sinomastodon and Stegodon,the Zhiren fauna bears the transitional characteristics of the typical Middle Pleistocene Ailuropoda-Stegodon fauna (s.s.) and Late Pleistocene Asian elephant fauna.The Zhiren fauna lacks the typical members of forest type of Southern China,such as Ailuropoda,Stegodon and Rhizomys,and probably indicates a biological event from Elephas kiangnanensis to Elephas maixmus,which is possibly related to origin of early modern human caused by climate transition.Both shrub-dwelling and grass-dwelling animal species are comparatively numerous from Zhiren fauna,indicating the forest was shrinking while the shrub and grassland were expanding at that time.This was probably the result of comparatively drier climate at that time.
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