广西崇左地区第四纪喀斯特溶洞发育,洞穴堆积中常含有丰富的哺乳动物化石,十余年的地质古生物调查中已发现多处第四纪不同时期的含有步氏巨猿(Gigantopithecus blacki)的洞穴化石点,共生的动物群中,独角犀(Rhinoceros)是化石数量最多、演化特征最显著的种类之一,对生物地层和环境变化有重要的指示意义.本文系统研究了产自崇左早更新世的鲤鱼山百孔洞和泊岳山巨猿洞的独角犀新材料,依据化石牙齿的大小和基本形态特征将其归入化石扶绥犀(Rhinocerosfusuiensis);此外,通过化石种和现生种冠高指数的比较研究表明,扶绥犀很可能栖息于温暖潮湿的森林环境中,这与现存于东南亚的苏门答腊犀的生活环境接近.扶绥犀是一种生存于早更新世早期(2.5～ 1.8Ma B.P.)的独角犀化石种,它往往与步氏巨猿(G.blacki)、中华乳齿象(Sinomastodon)、桑氏硕鬣狗(Pachycrocuta licenti、小种大熊猫(Ailuropoda microta)或武陵山大熊猫(A.wulingshanensis)以及山原貘(Tapirus sanyuanensis)或中国貘(T.sinensis)等动物共生,主要分布于中国南方,尤以广西地区最为集中.%Quaternary karst caves in the Zuojiang River area of Guangxi Zhuang Autonomous Region in Southern China are known to contain Pleistocene rich fossil records.These include unique finds of the primate Gigantopithicus blacki as well as a diverse associated vertebrate fauna dominated by mammalian remains with different ages.The Baikong Cave of Liyu Mountain and Juyuan Cave of Boyue Mountain are both located in the vicinity of the Chongzuo Ecological Park in the Zuojiang River area,Guangxi.Baikong Cave (22°17′45.3″N,107°29′54.42″E) is located on the western slope of Liyu Mountain near Banrong Village,about 3km north of the Chongzuo Ecological Park.Baikong Cave is a large tubular karst cave,and the elevation of the cave entrance is 216m a.s.l.It is the highest cave in the area with G.blacki remains.The Baikong fauna is characterized by the appearance of several relic Neogene genera (e.g.Sinomastodon and Hesperotherium),and some primitive species during the Pleistocene,such as Ailuropoda microta,Sinomastodon fiangnanensis,Pachycrocuta licenti,and Tapirus sanyuanensis.Paleomagnetic analyses demonstrate that the fossilbearing sediments in Baikong Cave are dominated by a reversed polarity.Combining the biochronological and magnetostratigraphic evidence,the Baikong sediments can be best correlated with the pre-Olduvai Matuyama reverse chron,which has an estimated minimum age of 2.0Ma.Juyuan Cave (22°17′21.9″N,107°30′40.1″E) is located on the eastern slope of Boyue Mountain,near the entrance of the Chongzuo Ecological Park.The elevation of the cave entrance is 206m a.s.l.The Boyue fauna is characterized by the co-occurrence of G.blacki,Pachycrocuta licenti,Ailuropoda wulingshanensis,Tapirus sanyuanensis and Sinomastodon yangziensis.The paleomagnetic data show that the fossil-bearing sediments in Juyuan Cave are of normal polarity.Combining the faunal analysis and magnetostratigraphic evidence,the Juyuan sediments can be best correlated with the Olduvai normal subchron,giving an estimated age of 1.8Ma.Fossil Rhinoceros is regarded as one of the most common faunal elements in Southern China during Quaternary.Recently,a large number of Rhinoceros dental remains from the Early Pleistocene Yanliang Cave (Chongzuo,Guangxi) have been described as Rhinocerosfusuiensis (Rhinocerotidae,Perissodactyla,Mammalia).The present study aims to provide a detailed morphological study of the additional Rhinoceros materials from Baikong and Juyuan caves,as well as their implications for Quaternary biostratigraphy and paleoenviromental changes in Southern China.Here,a total of 38 new Rhinoceros dental remains are described as R.fusuiensis based on the relatively small size and morphological characteristics.The comparison of hypsodonty index from extinct and extant rhinos suggests that R.fusuiensis very likely lived in a tropical forested environment with the humid and warm climate,which is similar to the environment of the living Dicerorhinus sumatrensis from Southeast Asia.In summary,the fossil R.fusuiensis lived during the early Early Pleistocene (2.5～ 1.8Ma B.P.) and was usually associated with other typical mammals during the early Early Pleistocene,such as Gigantopithecus blacki,Sinomastodon,Pachycrocuta licenti,Ailuropoda microta (or A.wulingshanensis) and Tapirus sanyuanensis (or T.sinensis).Moreover,the geographic distribution of R.fusuiensis is mainly limited to the south of the Yangtze River,especially concentrating in Guangxi Zhuang Autonomous Region.
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