介形类化石是微体古生物(Micropaleontology)化石中的一部分。在古无脊推动物的分类中属节肢动物门(Phylum Arthropoda),甲壳纲(Class Crustacea),介形类亚纲 (Subclass Ostracoda)。 介形类系双壳动物,左、右两壳中所包裹的动物体分节不明显,具有七对附肢。动物体仅能根据肢体的性质分为头部与躯干部。附肢是现代介形类分类的主要依据,可惜在化石中一般不易保存。 1.内部构造(插图1) Ostoid fossils are part of Micropaleontology fossils. Among ancient paleotoxins, Phylum Arthropoda, Class Crustacea and Subclass Ostracoda belong to the category of paleopox. Ostracoda bivalve animals, left and right shells wrapped in animal body section is not obvious, with seven pairs of appendages. Animal body can only be divided into head and torso according to the nature of limbs. Appendages are the main basis for the classification of the modern category, but unfortunately not generally preserved in fossils. 1. Internal Structure (Illustration 1)