Albaillellarian (radiolaria) assemblages across the Guadalupian–Lopingian boundary (Permian) and their environmental implications

Abstract

It remains unclear how radiolarian lineages adapted to the changing environments through the Guadalupian–Lopingian boundary (G-LB) interval. In this study, a well-preserved radiolarian fauna was obtained from silty cherts and siltstones deposited throughout the G-LB of the Sanpaoling, Yutouling, and Xiaqianling sections, located in Qinzhou City, Guangxi, China. Two genera of Albaillellaria, including ten species of and two species/morphotypes, are presented in this study. This assemblage is correlated with the Interval Zone. Based on the material obtained near the G-LB, the taxonomic value of pores on the test of species is here evaluated. This research documents a relatively significant morphological variation of the Albaillellarian lineages and an evolutionary reversal in through the G-LB. Based on the combination of the faunal and evolutionary response in the studied area, we suggest that the G-LB witnessed rapidly changing environmental conditions, imposing adaptive pressure on radiolarians, at least on the deep-dwelling Albaillellarians.