Insect Trace Fossil Associations in Paleosols: The Coprinisphaera Ichnofacies (original) (raw)

The previously proposed Termitichnus ichnofacies was defined to include all paleosol trace fossil assemblages. However, the available information indicates that terrestrial environments are far more complex. Therefore, it is suggested that the Termitichnus ichnofacies as presently defined be abandoned because it does not reflect the diversity of paleosol settings and fails to provide significant paleoecologic information. Formal definition of a Termitichnus ichnofacies in a more restricted sense, to include assemblages dominated by termite nests in paleosols of closed forest ecosystems, should await documentation of additional studies to prove recurrence. Other fossil insect-nest associations in paleosols (e.g., halictid nests in calcareous soils) do not have enough recurrence in time and space to be considered Seilacherian ichnofacies, but do represent potential ichnofacies. The model proposed in this paper includes the paleoecologically defined Coprinisphaera ichnofacies plus a definite number of associations, each one possessing its own paleoenvironmental implications, which do not show the necessary recurrence to be considered ichnofacies, at present. Climate and vegetation are considered key factors in the shaping of terrestrial ecosystems and should be taken into account for the definition of additional terrestrial ichnofacies.