A new extinct species of Scybalophagus dung beetle supports the collateral extinction hypothesis at the Chilean South American Pleistocene–Holocene boundary

Abstract

The extinction of megaherbivores (weighing over 1000 kg) at the Pleistocene–Holocene boundary caused drastic changes at multiple trophic levels. However, few examples of Pleistocene insect extinction have been reported in the literature. Here we describe a new extinct dung beetle species, Scybalophagus brellenthinae sp. nov., based on fossil remains recorded from an Upper Pleistocene sequence from Chilean Northern Patagonia (Osorno city: 40°34′S, 73°07′W) dated between ~16 400 and ~12 800 cal a bp. S. brellenthinae is shown to be a species of the genus Scybalophagus based on the following morphological characters: a bidentate clypeus, teeth separated by U-shaped emargination; protibiae with three major denticles on the external margin, separated by minor denticles, present at the base of the protibiae; and mesotibiae with prominent transverse carinae. Additionally, this new species can be clearly distinguished from extant species of the genus by its shiny green color. Extant Scybalophagus are true dung beetle species that depend on fresh mammal dung for their nest development. Therefore, we suggest that the mass extinction of the megaherbivores during a period of drastic environmental change at the Pleistocene–Holocene boundary in southern South America induced the collateral extinction of S. brellenthinae. Thus, this study provides new insights into dung beetle diversity of the past.