中国北方新发现的大角鹿化石

本文对两件大角鹿新材料做了描述、定种,同时对更新世大角鹿的系统发育关系和地理分布做了讨论。

TWO NEW SPECIES OF FOSSIL MEGACEROS FROM NORTH CHINA

Two new taxa(one species,one subspecies)of fossil Megaceros from Baotou,Nei Mongol and Mentougou,Beijing are described in this paper. Cervidae Gray,1821 Megaceros Owen,1844 Megaceros baotouensis sp.nov. Type A left antler,brow tine damaged(NM8601). Geological age and Horizon Late Pleistocene;A section,the 5th layer. Diagnosis A Megaceroid deer,the maintine of which is rather crooked and flat;the pal- mate part of the main tine is not developed. Megaceros ordosianus mentougouensis subsp.nov. Type A skull with complete brow tines(BM7901). Geological age and Horizon Late Pleistocene;B section,the 4th layer. Diagnosis A large Megaceroid deer with cylindrical brow tines;the central axes of the cylinder of both brow tines are subparallel to each other;the main tines extend to both external sides,which has longer antler pole. Discussion The specimen from Baotou differ from those of M.pachyosteus,M.falbella- teus,M.konwanlinensis,M.louchuanensis,M.sangganhoensis and M,ordosianus in having an- tlers with a small palmate part of the main tine;the main tine is rather crooked with nondiver- ging tines,M.yabei of Japan differs distinctly from baotou species in having antlers with two tines diverging at the palmate part of the main tines and a brow tine which rather extends,the Baotou form should be erected as a true species,for which the name Megaceros baotouensis is newly proposed. The new subspecies,M.ordosianus mentougouensis,also differs from other members of the genus by its cylindrical brow tines.But the specimen from Mentougou is similar to M.or- dosianus in shape,with the main tines extending to both external sides,which has a longer antler pole. The fossil Megaceros found in Eastern Asia are as follows: Megaceros ordosianus Young,1932; Megaceros pachyosteus Young,1932; Megaceros yabei Shikama,1938; Megaceros flabellateus Teilhard et Pei,1941; Megaceros konwanlinensis Chow et Hu,1965; Megaceros sangwonensis Kim-Singu,1974; Megaceros louchuanemis Xue,1982; Megaceros sangganhoensis Wei,1983; Megaceros baotouensis sp.nov.; Megaceros ordosianus mentougouensis subsp.nov. Judging by the characters of the brow tine and main tine it seems reasonable to assemble the phylogenetic relationship of Megaceros in Eastern Asia into two groups:One is,M.konwan- linensis(?)M.yabei(?)M.sangganhoensis(?)M.ordosianus.The other,M.konwanlinen- sis(?)M.flabellateus(?)M.pachyosteus(?)M.louchuanensis. The deposits yielding Megaceros fossils in Eastern Asia have been dated radiometrically. Their ages range from about 1.15 million years(M.konwanlinensis)to 0.035 million years (M.ordosianus)before present.