Uncovering the worldwide footprint of an ancient relictual lineage of harvestmen: new genus and species of Buemarinoidae from Australia (Opiliones: Laniatores: Triaenonychoidea)

Abstract

Phocyx gen. nov. and Phocyx australis sp. nov. have been newly described from New South Wales, Australia. This represents the first record of the family Buemarinoidae in Australia, thereby remarkably extending the known distribution of this ancient and relictual group of Opiliones. Our descriptions include images of genital morphology, a critical element in group diagnosis. Additionally, we present a discourse on the conserved external morphology within Triaenonychoidea and underscore the significance of genital morphology in the taxonomy of this superfamily. Very low species diversity and relict taxa surviving in scattered isolated refugia (tropical environments of the Southern Hemisphere and hypogean habitats of the Northern Hemisphere) are a clear signature that extinction probably played a major role in shaping the current distribution ranges of Buemarinoidae. That is also reflected in buemarinoid systematics by the prevalence of monotypic genera, a product of the large-scale extinction process affecting this old harvestman lineage.