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对湖北松滋黑档口早始新世洋溪组进一步采集和研究表明,该组下部黑色泥页岩乃是世界上罕见的早始新世猴鸟鱼化石库。不仅产有世界上最古老(距今5 500万年)的灵长类代表——阿喀琉斯基猴(Archicebus achilles Ni et al.,2013)、我国南方已知鹤形目化石最早记录——黑档口松滋鸟(Songzia heidangkouensis Hou,1990)、尖爪松滋鸟(Songzia acutunguis Wang et al.,2012)以及高丰度且保存完美的湖北江汉鱼Jianghanichthys hubeisis(Lei,1987)化石群,而且又新发现鬣蜥类(Agamid)、蝉(cicada)、蜘蛛(spider)、白蚁(termite)、古植物以及江汉鱼以外的多种鱼类化石。这是继北美绿江组(Green River Formation)、德国梅瑟尔(Messel)化石库(Fossillagersttte)之后,世界上新近发现的第三个早始新世特异埋藏群,在产出时代上较前两者早700万年。生物地层、构造古地理、沉积相和生态与埋藏学的分析研究表明,该特异埋藏群形成于早始新世初期江汉盆地西缘松滋-当阳盆缘凹陷之中。温湿的气候、充足的陆缘供给为盆缘凹陷及相邻低山-湿地中生物群的繁衍创造了条件;继之鄂西山地抬升和江汉盆地向东收敛而诱发的湖平面上升、咸化、滞流和缺氧以及(或者)盆地中部继之喷溢的基性火山熔岩而散发的有害气体和火山粉尘,可能是导致该生物群集群死亡的主要原因;伴随湖底缺氧而出现大量厌氧细菌席和藻类,在吸食生物软体的同时,为沉入湖底生物群骨架的完好保存创造了必要的封闭条件。
Further acquisition and research on the early Eocene Yangxi Formation in the Songziheidang Formation in Hubei Province shows that the lower part of the black shale in this group is a rare fossil pheasant reservoir in the world. It not only produces the world’s oldest (55 million years ago) primate representative - Achilles Chisinau (Archicebus achilles Ni et al., 2013), the earliest known crane-shaped fossil in southern China - - Songzia heidangkouensis Hou (1990), Songzia acutunguis Wang et al. (2012) and the highly conserved and well-preserved Jianghanichthys hubeisis (Lei, 1987) fossil community New species of Agamid, cicada, spider, termite, ancient plant, and various fish fossils other than Jianghan fish have also been newly discovered. This is the third newly discovered Eocene-specific burial group recently discovered in the world following the Green River Formation in North America and the Fossillagersttte in Germany. In the output era Seven million years earlier than the previous two. The analysis of biostratigraphy, tectonic palaeogeography, sedimentary facies, ecology and burial shows that this specific burial group was formed in the depression of Songzi-Dangyang basin in the early Eocene Jianghan Basin. In the warm and humid climate, abundant continental margin supplies create conditions for the basin edge depression and the multiplication of the biota in the adjacent low mountain-wetland. Following the rise of the western Hubei mountain and the eastward convergence of the Jianghan basin, the lake level rises, Harmful gas and volcanic dust emanating from the basic volcanic lava that followed the spillover in the central part of the basin due to stagnation and anoxia, and / or the central part of the basin may be the main cause for the death of this biota. With the hypoxia at the bottom of the lake, Anaerobic bacterial mats and algae, while ingesting the biologic software, create the necessary containment conditions for the well-preserved bioregion of the submerged lake.