演化动物群（英语：Evolutionary fauna）是由美国芝加哥大学古生物学家杰克·塞科斯基于1981年提出的概念，其利用化石记录的因子分析将自寒武纪至今（即整个显生宙）以来发展出的所有生物大致划分为三大动物演化群系。在展示演化动物群的发展过程中，通常以逻辑曲线的升降方式来显示出演化过程中生物多样性的增加和灭绝事件所导致的减少（人类所属的现代演化动物群目前尚未表现出该曲线的递减部分）。
演化动物群I（英语：Fauna I），又称“寒武纪演化动物群”，主要用于指代在寒武纪大爆发中首次出现，繁盛于奥陶纪大辐射并在奥陶纪-志留纪灭绝事件中绝大部分灭绝的化石动物类群。其主要包括三叶虫、小壳动物群（塞科斯基将其归类为“多毛纲”，但也同时包括cribricyathids、coleolids和volborthellids）、单板纲、无铰纲腕足动物以及软舌螺等等。该演化动物群中的动物仅极少数经过五次大灭绝事件而存续至今，其中则包括海豆芽。
Fauna II, known as "Paleozoic", described as a "Brachiopod-rich assemblage", accounts for most of the fossils appearing in the Great Ordovician Biodiversification Event, and largely became extinct in the Permian-Triassic extinction event. This fauna is marked by fossils of the following classes: Articulata, Crinoidea, Ostracoda, Cephalopoda, Anthozoa, Stenolaemata, Stelleroidea.
Fauna III, known as "Modern", described as a "Mollusc-rich assemblage", arose largely in the Mesozoic-Cenozoic Radiation, still in progress. The following classes are included: Gastropoda, Bivalvia, Osteichthyes, Malacostraca, Echinoidea, Gymnolaemata, Demospongiae, Chondrichthyes.
In the mid-19th century, John Phillips suggested three great systems: Palaeozoic, Mesozoic and Caenozoic. Writing after Sepkoski, Brenchley and Harper suggested that there were two early evolutionary faunas before the three of Sepkoski: Ediacaran and Tomottian. They also point out similarities with four "evolutionary terrestrial plant floras": Early Vascular, Pteridophytes, Gymnospores, Angiospores; and three "evolutionary terrestrial tetrapod faunas": "Megadynasty I (Carboniferous-early Permian)" "primitive amphibians and reptiles, most notably ... ", "Megadynasty II (early Permian-mid-Triassic)" "mammal-like therapsids", and "Megadynasty III (late Triassic-Cretaceous)" "included the age of the dinosaurs".
