西伯利亚阿芳托娃戈拉遗址旱獭与古环境研究

A study on Marmota sibirica and the paleoenvironment of Afontova Gora site,Siberia

阿芳托娃戈拉(Afontova Gora)遗址位于俄罗斯西伯利亚叶尼塞河上游右岸的3级阶地,地理坐标北纬55.9°94′83″,东经92.5°08′31″。该遗址出土有晚期智人化石和丰富的打制石器、骨制品、动物化石等,是西伯利亚地区旧石器时代晚期的重要文化遗址之一。遗址剖面第12层约17.0 ka B.P.。从该层出土的哺乳动物化石中,鉴定出4个个体的西伯利亚旱獭(Marmota sibirica)化石材料。西伯利亚旱獭颅骨呈松鼠型,眶上突和矢状嵴发达;腭面宽大,左右颊齿间距在M1处最宽;下颌骨粗壮,水平支较高,冠状突较短而粗壮;颅骨全长113.5 mm,眶间距28.8 mm,P4~M3长27.8 mm。从颅骨、颊齿测量数据上比较发现,西伯利亚旱獭(M.sibirica)明显大于早更新世绝灭种小旱獭(Marmota parva)和现生种草原旱獭(Marmota bobak)。牙齿形态特征上,西伯利亚旱獭具有一定原始性,其下颊齿下中尖粗壮,与早更新世小旱獭有一定相似性;但与小旱獭相比也有明显进步性,如P4臼齿化、下颊齿下后脊高度退化等。遗址动物群生态和地层堆积综合分析显示,阿芳托娃戈拉遗址古环境属于温带森林草原环境,与现今相比,其植被类型、植被丰度、降水量及野生动物种群多样性等更显丰富。阿芳托娃戈拉遗址动物群,是西伯利亚旧石器时代遗址中动物种属最丰富的地点,该遗址动物群面貌一年四季均具有代表属种的特点。该特点反映西伯利亚旧石器时代晚期古人类曾长期定居此地;对本区域动物资源非常熟悉,并掌握有常年获取肉类资源的生产技术。遗址中批量存在的旱獭动物遗存,是该遗址古人类春季食物资源的重要组成成分。可能是在春季待旱獭出蛰后,对刚刚性成熟发情期间疏于自我防卫的青年个体进行捕获。该发现丰富了我们对西伯利亚古人类开发食物资源生产方式的认识,也反映更新世晚期古人类对西伯利亚地区具有很强的环境适应能力。

The Afontova Gora site(55.9°94′83″N,92.5°08′31″E)is located in the Upper Yenisei,Siberia,Russia,on the right bank(the third terrace).The site unearthed Homo sapien fossils and plenty of chipped stone tools,bone artefacts,and animal fossils.It is one of Siberia's important Paleolithic sites of the Upper Paleolithic Age.Layer 12 of the deposit dates back to ca.17.0 ka B.P.We identified Marmota sibirica specimens out of mammal fossils excavated from L12 and calculated as 4 individuals by MNI.Marmota sibirica has a sciuromorphous skull with a well-developed supraorbital process and sagittal crest.The palatine surface is wide,and the maximal diameter of the upper cheek teeth rows is between the M1s.The mandible is robust,with a comparatively high horizontal ramus and a relatively short and stout coronoid process.The greatest length of the skull is 113.5 mm,the interorbital breadth is 28.8 mm,and the length of P4~M3 is 27.8 mm.Based on the measurements of the skull and cheek teeth,M.sibirica is larger than Marmota parva,an extinct species of the Early Pleistocene,and the living species Marmota bobak.Regarding dental morphological features,Marmota sibirica has robust mesoconids like that of Marmota parva,regarded as a primitive trait.Compared with Marmota parva,Marmota sibirica has molarized P4 and largely reduced metalophid height,regarded as advanced features.After a comprehensive analysis of fauna features and stratigraphic deposits,the paleoenvironment of this site was temperate forest-steppe,which indicates it has more abundant vegetation type,plant species richness,annual precipitation,and fauna diversity than that of today.The Afontova Gora fauna has one of the most prosperous animal species among these Siberian Paleolithic sites.The fauna fossils include representative animals of four seasons.That features indicate that ancient humans settled down here in the Upper Paleolithic Age for a long time and had the knowledge and technique to access animal resources year-round.This batch of Marmota sibirica remains suggested to be an essential component of food resources in Spring.They are young individuals reaching sexual maturity,probably or rutting and captured when they just emerged from dormancy and lacking self-protection awareness.These findings enrich our knowledge of how ancient humans explored food resources and connote their strong environmental adaptiveness and capability in Siberia during the Late Pleistocene.