燕子石,又名蝙蝠石,是古生物化石中的一种。这种化石的古生物学名为三叶虫,生活在海底下古生代寒武纪时期,距今5亿多年。三叶虫虫体通常是两侧对称,体分节,这是节肢动物的主要特征。它们的某些节肢可以愈合起来形成头、胸、尾三个部分,前部为头或头甲,中间为胸部或胸甲,后部是尾或尾甲。其背侧甲壳被两条纵向背沟划分为中轴及两侧肋叶,这是所有三叶虫结构的特征,也是三叶虫名称的由来。过去我们所见到的燕子石上的虫体多是支离破碎、头尾分离的不完整虫体。最近在鲁中地区发现了极完整的虫 Swallow stone, also known as bat stone, is a kind of paleontological fossils. This fossil paleontology called trilobite, living in the sea under the Paleozoic Cambrian era, dating back 500 million years. Trilobite worms are usually symmetrical on both sides, body segmentation, which is the main characteristics of arthropods. Some of their joints can heal up to form the head, chest and tail of the three parts, the front of the head or headdress, chest or breastplate in the middle, the tail is tail or tail. The dorsal carapace is divided by two longitudinal ditch into the central axis and both sides of the rib, which is the characteristics of all Trilobite structure, but also the origin of Trilobite name. In the past we have seen the swallows on the stones are mostly fragmented, head and tail separation of incomplete insects. Recently, extremely complete insects were found in central Luzhong