黑龙江阿城交界洞穴遗址的哺乳动物群

PLEISTOCENE MAMMALIAN FAUNA FROM THE JIAOJIE CAVE AT ACHENG,HEILONGJIANG PROVINCE

黑龙江阿城交界旧石器时代洞穴遗址出土的哺乳动物化石主要来自洞穴堆积下部的第5层和第6层,目前鉴定出12个种类,以北方种类为主,缺少披毛犀和猛犸象等典型的喜冷种类,是生存于亚温暖期向寒冷期过渡阶段的北方动物群。交界动物群以含原东北鼢鼠相似种、东北兔(翁氏兔)和梅氏犀等中更新世类型为特征,在组成土与中更新世中晚期的金牛山和庙后山动物群、晚更新世的小孤山动物群和古龙山动物群接近。堆积下部第6层出上的化石种类可能生存于距今154～266ka之间的亚温暖期(倒数第二冰期Ⅱ和Ⅲ阶段之间)末尾,适合喜温的梅氏犀及对温差适应能力较强的北京斑鹿、斑鬣狗等大型动物的生存;而出土于第5层的化石种类可能生存在暖冷交替的倒数第二冰期Ⅲ阶段初始(距今154ka)附近,适合旱獭、原东北鼢鼠、东北兔等小型草原型哺乳动物的生存。交界动物群生存时期的环境为草原与森林镶嵌存在,在亚温暖期时(下部第6层堆积时期)的森林面积较大,而在冷暖期转变时(次下部第5层堆积时期)森林面积缩小、草原面积增加。

The Jaioji Province. It is e Paleolithic Site is located in a karstic cave at Acheng, Haerbin Municipality in Heilongjiang regarded as the oldest Paleolithic site in the province and also the northernmost one in China up to today. The geographic coordination at the cave entrance measured with the Global Positioning System （GPS）is 45°21′07.7″N and 127°05′16. 8″E, with an altitude of 183m. The cave deposits can be divided into 6 layers. Mammalian fossils were unearthed mainly from Layers 5 and 6 in the lower part of the cave deposits. As a Quaternary mammalian fauna,it is chronologically the earliest one in Heilongjiang Province and geographically the northernmost and easternmost in China. Layer 5 is composed of grayish green clay with some yellow clods,and the underlying Layer 6 composed of reddish yellow clay with breccia. Although the site was discovered in 1996 and systematically excavated in 1997 ,the fossils were never systematically described before 12 taxa were identified as follow ： Marmota sp., Myospalax cf. prosilurus , Ochotona sp., Lepus （ Eulagos ） mandshuricus （ = Lepus wongi ） , Martes sp., Meles meles , Mustela sibirica , Ursus sp, Crocuta sp., Stephanorhinus kirchbergensis （ = Dicerorhinus mercki ） , Cervus （S.）nippon hortulorum, Capreolus capreolus manchuricus. The fossils from Layer 5 are mostly smaller forms such as Marmota sp., Myospalax cf. prosilurus, Lepus （Eulagos） mandshuricus （ = Lepus wongi） , etc., and those from Layer 6 are mostly larger forms such as Stephanorhinus kirchbergensis , Cervus （ Sika ） hortulorum , Crocuta etc. They are mostly northern forms. The fauna lacks typical cold forms such as Coelodonta and Mammuthus, and it was regarded as a fauna exsiting during the transition from temperate period to cold one in North Region. The comparison of fauna compositions shows that the Jiaojie fauna is close to that of the Middle Pleistocene Jinniushan and Miaohoushan faunas in Liaoning Province, the Late Pleistocene Xiaogushan and Gulongshan faunas, also in Liaoning Province. The fauna is therefore biochronologically dated as the late stage of the Middle Pleistocene. It is in accordance with the uranium series dating of 175kaB. P. on the teeth of Stephanorhinus kirchbergensis from Layer 6. The fossils from Layer 6 likely hold the temperate end period from 154kaB. P. to 266kaB. P. （between stages Ⅱ and Ⅲ of the Penultimate Glaciation ）, suitable for the habitation of temperate forms such as Stephanorhinus kirchbergensis, Cervus（Sika） hortulorum, Crocuta etc. And those from Layer 5 likely hold the time period of the beginning of the Penultimate Glaciation Stage Ⅲ （154kaB. P. ）, suitable for the habitation of pro-cold forms such as Marmota sp., Myospalax cf. prosilurus, Lepus （Eulagos） mandshuricus （ = Lepus wongi ） , etc. Both forest and grassland were discoverd but the scale of forest was larger in the temperate period （ e. g. during the formation of Layer 6） and was contained due to the expansion of grassland during the the formation of Layer 5）.