Thalassinoides ichnofabrics from the Zhangxia Formation (Cambiran Miaolingian series) in Henan province: Bioturbators as Ecosystem engineers

Bioturbation, a crucial ecosystem engineering behavior in marine environments, significantly influences fluid flow and the physical environment. Trace fossil records serve as valuable tools for understanding the impact of bioturbation by ecosystem engineers on sedimentary substrates. This study utilizes the abundant trace fossil Thalassinoides found in the Zhangxia Formation of the Middle Cambrian (Miaolingian, Wuliuan) in the Dengfeng section of western Henan Province, China, as research materials to analyze the evolution of trace makers' ecosystem engineering behavior and its influence on sediment mixing. Investigations reveal that the producers of Thalassinoides adopt diverse survival strategies in response to environmental changes, leading to varying degrees of sediment mixing. Despite the potential impact of environmental fluctuations on benthic organisms, constraining their excavation into deeper sediment layers, the complex engineering behaviors of the ecosystem continued to evolve during the mid-Cambrian period. These ecosystem engineers not only modify the sedimentary substrates, expanding ecological space, but also potentially accelerate the rate of nutrient cycling in the seafloor, thereby serving as a driving force for further prosperity within the early Paleozoic benthic communities. •The Image J machine training method is used for the first time to automatically identify the bioturbation structure in the field images, and the amount of bioturbation is quantitatively analyzed.•This study provides a new idea and method for the transition from qualitative analysis to quantitative analysis in the study of trace fossils.•In the framework of ecosystem engineering, the evolution of behavior in Thalassinoides tracemakers is elucidated, along with its impact on sediment substrate.