摘要
粪化石是一种重要的遗迹化石,不但可以提供生物饮食结构、生物种群多样性等信息,还可以重建古生态系统的营养结构和能量流模型,但常是单点发现,鲜有报道区域上连续的粪化石层。本文报道了在重庆渝北、北碚、万州、四川邻水等地区的下侏罗统自流井组东岳庙段中发现的以粪化石为主、伴生鳞齿鱼类、叶肢介类、芦木类、爬行类等生物的化石层位,并对化石层中的粪化石进行了采样。据粪化石的形态观察及薄片特征认为:①采集的粪化石分为了四个类型,其动物源主要为不同食性的爬行类、硬骨鱼类及软骨鱼类。②东岳庙段时期古巴蜀湖形成了由茂盛植物作为生产者,双壳、介形虫作为初级消费者,鱼类、爬行类作为中—高级消费者构成的复杂生态系统。③东岳庙段时期古巴蜀湖发生了一次小型的缺氧事件,导致了大量鱼类集群性死亡,爬行类可能由于可以脱离水体呼吸而免遭其难,这次缺氧事件可能是托阿尔期大洋缺氧事件的序幕。
Coprolites are important vestigial fossils,which can provide information on dietary structure and population diversity of organisms,as well as reconstruct nutrient structure and energy flow models of ancient ecosystems.However,coprolites are often found in separate locations,and rarely regional continuous coprolites layer has been reported.This paper reports for the first time on the fossil horizons of coprolites,associated with leptodonts,phyllopods,alamites and reptiles found in the Dongyuemiao Member of the Ziliujing Formation in Yubei,Beibei,Wanzhou of Chongqing and Linshui of Sichuan in the Lower Jurassic,and samples the coprolites in the fossil beds.According to the morphological observation and thin section characteristics of coprolites,it is concluded that:①The collected coprolites are divided into four types,and their animal sources are mainly reptiles,bony fishes and cartilaginous fishes with different feeding habits.②During the Dongyuemiao period,the Paleo-Bashu Lake formed a complex ecosystem composed of lush plants as producers,bivalves and ostracoda as primary consumers,and fish and reptiles as medium-high consumers.③A small anoxic event occurred in the Paleo-Bashu Lake during the Dongyuemiao period,which led to the death of a large number of fishes in a cluster,and reptiles may were spared the trouble because they could breathe out of the lake.This anoxic event may be the prelude to the oceanic anoxic event of the Toarcian Age.
作者
周政达
陈阳
栾进华
张瑞刚
王倩
张拉
李伟
李大华
聂磊
ZHOU Zhengda;CHEN Yang;LUAN Jinhua;ZHANG Ruigang;WANG Qian;ZHANG La;LI Wei;LI Dahua;NIE Lei(Chongqing Key Laboratory of Resource and Environmental Effects of Major Geological Events(Chongqing Institute of Geology and Mineral Resources),Chongqing 401120,China)
出处
《地质学报》
北大核心
2025年第9期2900-2907,共8页
Acta Geologica Sinica
基金
重庆市技术创新与应用发展专项重点项目(编号CSTB2023TIAD-KPX0098)
重庆市规划和自然资源局科研项目(编号KJ-2023011)
重庆市科研机构绩效激励引导专项(编号cstc2022jxjl00008)
重庆地质矿产研究院科研平台开放课题(编号CKLEMME-202201)联合资助的成果。
