Fuxianhuiida

 ( Arthropod Taxa ) 

Fuxianhuiida is an extinct clade of from the Cambrian of China. All currently known species are from Cambrian Series 2 aged deposits in Yunnan, including the Chengjiang biota. Although historically suggested to be members of the arthropod stem group recent research has suggested that they may be closely related to Mandibulata. Many specimens are known with exceptional soft tissue preservation, including preserved guts and Nervous tissue, which given their basal phylogenetic position makes them important in understanding the evolution of Arthropoda as a whole. They reach a size of up to 15 cm, and are interpreted as Benthic zone predators and scavengers. The Fuxianhuiid exoskeleton is unmineralised, and the number of Tergum ranges from 15 to over 40. The cephalon is covered by a head shield and contains stalked eyes connected by the Sclerite, antennae, a butterfly shaped hyposome and a posterior facing mouth. Fuxianhuiids possess specialized post-antennal appendages with serrated edges used for food processing. The presence of in members of Chengjiangocardidae suggests that they were capable of durophagy. In most Fuxianhuiids, the Thorax narrow posteriorly, terminating in either a swimming paddle or paired flukes with a tail spine. In members of Fuxianhuiidae the thorax is divided into two sections, the anterior wide opisthothorax and the posterior narrow limbless tail-like abdomen.

It has been suggested that Shankouia zhenghei is synonymous with Liangwangshania biloba, with sexual dimorphism accounting for variation between specimens.