【作者】 陈冠芳；

【Author】 CHEN Guanfang;Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences;

【机构】 中国科学院古脊椎动物与古人类研究所；

【摘要】 对山西榆社盆地早上新世中间中华乳齿象[Sinomastodon intermedius(Teilhard et Trassaert,1937)]的化石和归入此属的、我国其他地点的乳齿象种进行再研究后,得出下列结论:中华乳齿象包括4种:中间中华乳齿象(S.intermedius),汉江中华乳齿象(S.hanjiangensis Zong,1989),扬子中华乳齿象[S.yangziensis(Chow),1959]和中华乳齿象不定种(Sinomastodon sp.);它们分别出现在上新世至更新世中期的中国北方和南方;由于生态环境的变化,它们从北向南有三次较大规模的扩散和迁移。更多还原

【Abstract】 Sinomastodon was created by Tobien,Chen et Li in 1986 on the basis of the species Mastodon inter-medius Teilhard et Trassaert,1937 from the Early Pliocene of Yushe Basin,Shanxi Province,China.It is a firm genus because it is distinguished by the particular combination of cranial and mandibular elephan-toide shape（cranium compressed antero-posteriorly and high vertically,reduced mandibular symphysis with narrow gutter and lacking mandibular tusks）,and like gomphothere’s molars（bunodont and trilo-phodont intermediate molars,etc.）.The type species,Sinomastodon intermedius（Teilhard et Trassaert）,1937,was considered by Tobien et al.^[1].to be unique in the genus.The species Trilophodon cf.T.wimani and Trilophodon cf.T.spectabilis from the ’Yushe I Zone ’of Yushe basin,Shanxi Province,Trilophodon yangziensis Chow,1959 from the Early Pleistocene of Wu Shan,Sichuan Province,Trilophodon guangxiensis Chow,1959 from the Late Pliocene of Chongzuo,Trilophodon serridenstoides Pei,1987 and T.liuchengensis Pei,1987 from the Early-Middle Pleistocene of Liuzhou,Guangxi Province,Rhynchotherium huananensis Chow et Zhang,1974 from the Late Pliocene of Zhaotong,Yunnan Province,and T.wufengensis Pei,1965 from the Middle Pleistocene of Wufeng,Hubei Province etc.were regarded by them as its synonym.Meanwhile,they proposed that it would be of a Late Tertiary immigration from North America via Beringia.Zong et al.^[3,4].considered anyone of these above mentioned species may be distinct and valid in Sinomas-todon,except for the Trilophodon cf.T.spectabilis belonging to Gomphotherium.After restudying and observing these specimens referred to the above mentioned species,the present paper comes into the following conclusions.1) Four species are recognized in the genus Sinomastodon.They are:S.intermedius（Teilhard et Trassaert）,1937[= Mastodon intermedius Teilhard et Trassaert,1937= Trilophodon cf.T.wimani^[2].= Trilophodon cf.T.spectablism S.hanjiangensis Zong et al.,1989[= S.yanyuanensis Zong,1987= Gomphotherium yongrenensis Zhang,1980= Rhynchotherium huananensis Chow,1959= Sinomastodon sp.^[12].S.yangziensis（Chow）,1959[= Trilophodon yangziensis Chow,1959= T.guangxiensis Chow,1959= T.wufengensis Pei,1965= Gomphotherium serridentoides Pei,1987= G.liuchengensis Pei,1987]Sinomastodon sp.[= Pliomastodon cf.P.matthewi,^[18].2) Sinomastodon Tobien et al.,1986 is known from the Early Pliocene and Early-Middle Pleistocene of China.The species S.intermedius represented a primitive form.S.hanjiangensis would be derived from it.The species S.yangziensis may be a late representative of the genus and came from the Pleistocene cave and fissures deposits of South China.3) It is questionable that it shows affinities with the bunodont-brevirostrine-trilophodon Mastodon,like Stegomastodon,Halpomastodon,Notiomastodon and Cuvieronius etc.from the Late Tertiary of North America.The reasons are:（1） No remains belonging to the genus have been reported from the transitional region between China and North America during the Pliocene and Pleistocene.（2） The structures of the molars in Sinomastodon are simpler than in the mastodonts of North America.（3） The occurrence of the mastodonts of North America would be the same time with ones from China or little later.It is possible that it may be derived from the Gomphotherium-like type of the Miocene of the Old World.4) Three dispersal events of Sinomastodon were recognized from the Pliocene to the Middle Pleistocene of China.The first occurred at the Early Pliocene（about 4.8 Ma B.P.）,in which Sinomastodon first appeared in the Yushe Basin,Shanxi Province.The species S.intermedius is the representive.It may be extinct at about 3.5 Ma B.P.The second occurred at between Early Pliocene and Late Pliocene（about 3.5 Ma B.P.）.During the period Sinomastodon migrated from Yushe Basin to the middle part of China（Shanxi,Sichuan） and to south Yunnan.The species S.hanjiangensis is the representive.It may be extinct at the end of Pliocene or Early Pleistocene（about 2.5 Ma B.P.）.The third occurred at Early Pleistocene（about 2.5 Ma B.P.）,in which Sinomastodon has arrived in south part of China.The species S.yangjiensis is the representive.It may be extinct at Middle Pleistocene.更多还原