Insect trace fossils i Pleistocene deposits from the Pityusic Islands (Balearic Archipelago, Western Mediterranean): Ichnotaxonomy and palaeoenvironmental significance

Abstract

[eng] Insect trace fossils attributable to the Celliforma ichnofacies (Rebuffoichnus casamiquelai and Palmiraichnus castellanosi) are recorded from the Pleistocene deposits of nine sites from the Pityusic islands. These deposits, characterized by aeolian and colluvial strata interbedded with two types of palaeosols with a high amount of trace fossils, show a strong relationship with environmental changes occurred during the Pleistocene. The Celliforma Ichnofacies is typical of well-drained palaeosols with low vegetation indicating semiarid to sub-humid conditions. According to the abundance of ichnospecies in each type of palaeosol, Palmiraichnus castellanosi indicates that bees preferred to nest in wetter conditions, whereas Rebuffoichnus casamiquelai, indicates that coleopterans could live under drier conditions, even in this case when its abundance is relatively high within periods with increased rainfall.