Epibiosis and epifaunal tiering in brachiopods from the Cambrian Xiaoshiba Lagerstätte of China

In the early Cambrian, brachiopods quickly became a distinctive group of the marine community and played a key role in the increasingly diversified benthic ecosystem. Based on new material from the Cambrian Stage 3 Xiaoshiba Lagerstätte, we focus on brachiopods displaying epibiotic relationships and tiering attachment to demonstrate: 1) abundant individuals of Kutorgina chengjiangensis once acted as the predominant components to construct the cohesive substrate, which were often selected by epibionts as their hosts for shallow-sea inhabitation, exhibiting a symbiotic association; 2) within the same community, the secondary tierers are well recorded at least by some of acrotretoid brachiopods attaching to gregarious tubes of Tubulella sp. Our findings give additional evidence for illuminating the unexpected complexity of the palaeoecosystem and clarifying the rapid adaptive radiation and ecological niche expansion associated with early Cambrian brachiopods.