东兰国家地质公园兰木化石群主要以菊石为主，品种繁多，其中Protrachyceras、Joannites两属频繁出现，是世界各地海相拉丁期地层中的常见属。我国拉丁期菊石的分布较局限，产出的Protrachyceras ladinum Mojs、Joannites kossmati Diener现尚见于我国西藏阿里地区南部的拉丁期地层。兰木化石群不仅丰富了我国拉丁期菊石群的内容，同时对于区域地层的划分、对比及古环境、古地理的研究均有重要的意义。 There are many types of fossils in Mulan fossil group of Donglan National Geopark, among which ammonite is the most typical type. The most common category are Protrachyceras and Joannites, which are common in Marine facies Latin strata formation around the world.