The implications of Cambrian lobopods for origin of arthropods

• 1、Early Life Institute and the Key Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China

Abstract：The Early Cambrian Chengjiang Lagerstätte, located in the Eastern Yunnan of China, has been regarded as a crucial window to observe the radiation of the metazoan because of the well preserved soft-bodied fossils. Arthropods, as a predominant group in living animal kingdom (accounting for ~80% of the total species), also has the greatest diversity in the number and morphology in Early Cambrian Chengjiang Lagerstätte (about half of the total species). Thus, the origin and diversification of arthropods is one of the most hotly-debated subject. Arthropods used to be thought closely related with annelids, but they are now believed to be separated into two major realms within Protostomia on the basis of new molecular data, i.e. the Ecdysozoa and Lophotrochozoa respectively. Therefore, the study of extinct “stem groups” provides the key to understand the early evolution of and the origin of the arthropods. The paleontologists had done a lot of hard work and found the Cambrian lobopods bore pairs of non-segmented primitive limbs might be ancestral to all arthropods. Based on the information of Miraluolishania、Jianshanopodia and Megadictyon, we have made some progresses in tracing relationship between lobopods and arthropods.

Keywords： Lobopod, arthropods, Cambrian, Chengjiang fossil Lagerstä tte