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松辽盆地晚中生代经历了热隆张、裂陷、坳陷和萎缩４ 个地质演化阶段，后３ 个阶段相应发育了三大生物群，即热河生物群、松花江生物群和明水生物群。通过对三大生物群中介形类和叶肢介的演化史研究，认为环境的变化影响和控制着生物的发生、发展和繁盛。构造活动期，生物组合具有低分异度、低丰富度的特点，化石的纹饰结构也相对简单；构造平稳期，湖生生物迅速发展并繁盛，生物组合具有高分异度、高丰富度的特点，化石壳面纹饰结构趋于复杂化、多样化。从单一超层序的沉积体系域演变来看，随着古湖盆水体的进侵和加深，生物组合特征也表现为由低分异度、低丰富度逐渐向高分异度、高丰富度发展，并且化石壳面纹饰结构有由简单逐渐向复杂化、多样化方向演化发展的趋势；从化石的横向分布来看，滨浅湖相暗色泥岩中化石含量最丰富，其次是三角洲前缘相和三角洲分流平原相，深湖相、山前平原淤积相和泛滥平原相中少见化石。生物在其地史演化进程中，记载了环境变迁信息，因此，可以通过分析沉积盆地中产出的化石组合特征，再现古地理、古环境。
The Late Mesozoic in the Songliao Basin experienced four stages of Geolongzhang, rifting, depression and atrophy. In the latter three stages, three major biota, ie, Jehol Biota, Songhuajiang Biota and Mingshui Biology group. Through the study of the evolutionary history of the meso-types and the leaf extremities in the three biomes, it is believed that the environmental changes will affect and control the occurrence, development and prosperity of the organisms. In the period of tectonic activity, the biological assemblage has the characteristics of low degree of differentiation and low abundance, and the decorative structure of fossils is also relatively simple. In the stable period, the lake organisms develop rapidly and prosperously, and the biological assemblages have high degree of differentiation and high abundance Features, fossil shell surface decoration tends to be complicated and diversified. From the evolution of the sedimentary system domain of a single super-sequence, with the invasion and deepening of the ancient lake basin water bodies, the characteristics of the biological assemblage are also characterized by low-degree of differentiation, low-level richness gradually increasing to high-degree of differentiation and high abundance And the fossil crust ornamentation tends to evolve from simplicity to complexity and diversification direction. According to the horizontal distribution of fossils, the fossil content of the dark mudstone of the shallow coastal facies is the richest, followed by that of the delta front And deltaic distributary plain facies, deep lacustrine facies, sedimentary facies in the piedmont plain, and rare fossils in the flood plains. Creatures record the information of environmental changes during the evolution of their history. Therefore, the paleogeography and paleoenvironment can be reconstructed by analyzing the fossil assemblages produced in the sedimentary basins.