Zoophycos macroevolution since 541 Ma.

Abstract

Zoophycos is one of the most complex and enigmatic trace fossils recorded in marine strata from Cambrian to Quaternary worldwide, which is invaluable for the study of Phanerozoic development of organism–environment interactions. Here we address and demonstrate the macroevolution of Phanerozoic Zoophycos by assembling 448 points in constructing the Phanerozoic Zoophycos database based on 291 papers from 1821 to 2015 and 180 specimens from Cambrian to Palaeogene. The comprehensive dataset reveals, for the first time, five peaks and six depressions in Phanerozoic Zoophycos occurrence frequency. Secondly, the palaeogeographical distribution of Zoophycos is closely associated with the supercontinent Pangaea shifting, independent of the latitude. Our data also attest that the bathymetrical shift of Zoophycos from the littoral–neritic to bathyal environments is synchronized with the tiering shift from shallow to deep. By detailed comparison with body fossils, geochemical and palaeogeographical records, we conclude that the macroevolution of Phanerozoic Zoophycos is multi-affected by the global biodiversity expansion, benthic nutrient enhancement, and the biotic macroevolution of the Zoophycos-producers. The macroevolution of development evidenced by the morphological changes of Zoophycos and other trace fossils, may have great implications on the behavioural and physiological adaptation of ancient animals to the environments.