Termite nests in eolian backshore settings: An unusual record throughout the quaternary in the neotropical realm

Abstract

In this paper, we report the unusual presence of extant termite nests in frontal beach eolian sandy substrates in the Rio Grande do Sul Coastal Plain (southernmost Brazil) and describe the nest architectures, aiming to compare them with termite fossil nests preserved in Pleistocene backshore deposits of this same coastal plain. Four sites were analyzed along the modern beach, and the architecture of the termite nests was described. The nests are composed of a rounded convex epigeal portion and a hypogeal portion with variable dimensions formed by interconnecting spherical to semispherical chambers. Considering that termites are assumed to colonize more mature, vegetated soils due to the need for abundant cellulosic material, the occurrence of termite nests in backshore dunes close to the shoreline opens a discussion about the distribution and habit of termites and the applicability of their trace fossils for paleoenvironmental reconstitutions.