The Origin of Mites: Fossil History and Relationships

Abstract

Mites are members of the arthropod subphylum Chelicerata, a group with a long fossil history of about 500 million years (Dunlop 2010) (Fig. 2.1). The earliest chelicerate fossils are known from the Cambrian and appear to be related to a group of anomalous arthropods with large, raptorial anterior appendages in place of antennae (Haug et al. 2012). Within the Chelicerata, the mites are placed among the terrestrial lineages known as the Arachnida. Thus, to understand the origin of mites, we must peer back through the mists of time and seek answers to these basic questions: What is an arthropod? Why are chelicerate arthropods different from other arthropods? What does it mean to be an arachnid? Which arachnids are the closest relatives of mites?