SPATIAL RELATIONSHIPS OF EDIACARAN COMPLEX TRACE FOSSILS LAMONTE TREVALLIS

The spatial relationships of trace fossils record animal behaviors, offering clues on foraging behavior that can be used to infer the interactions between trace makers and local environments. In our study, we employed spatial point process analyses (SPPA) to examine the spatial patterns of the Ediacaran trace fossil, Lamonte trevallis, on a 6.7 m² rock surface, found in the Shibantan Member limestone of the upper Ediacaran Dengying Formation of South China. This trace fossil is characterized by horizontal tunnels connected with vertical burrows. Our analysis using the pair correlation functions suggests the aggregation of traces on a small scale (<15cm), which infers a preference for resources and reveals the lateral heterogeneity of the environment. Moreover, the mark correlation functions indicate an aggregation of segments of similar lengths, with a right-skewed length distribution of segments, characterized by numerous short segments with rare long segments. This distribution is consistent with the pattern of Lévy flights, which represents an optimized foraging strategy in response to heterogeneous resources. Additionally, the arrangement of isolated pit-shaped vertical traces, interpreted as L. trevallis formed after the deposition of the studied layer, resembles the aggregation pattern of connected vertical burrows of L. trevallis on the same surface. This similarity indicates persistent foraging behavior by the trace makers, in an environment where resources are abundant yet unequally distributed.