A Systematic Revision of the South African Pettalidae (Arachnida : Opiliones : Cyphophthalmi) Based on a Combined Analysis of Discrete and Continuous Morphological Characters with the Description of Seven New Species

Abstract

The cyphophthalmid family Pettalidae in South Africa is revised and seven new species are described from museum material collected between 1939 and 1985. Two of these are placed in the genus Purcellia and five in Parapurcellia, bringing the total number of described South African cyphophthalmids to 15. In addition, Purcellia peregrinator is transferred to the genus Parapurcellia. Phylogenetic analyses of discrete morphological and continuous morphometric characters, both separately and in combination, support the generic assignments and contribute towards a more detailed understanding of the systematics of the group in South Africa. In order to assess the stability of our phylogenetic results, the different morphological datasets were analysed under equal and implied weighting, as well as under several weighting schemes that varied the respective contribution to tree length of the discrete and continuous data partitions. These variations generated two phylogenetic hypotheses: (1) monophyly of the South African pettalids + Austropurcellia from north-eastern Australia as a derived clade within Pettalidae; and (2) polyphyly of the South African pettalids with Parapurcellia basal within Pettalidae. The latter hypothesis is congruent with previous molecular phylogenies of Cyphophthalmi, and has moderate bootstrap support. The sisterhood of Purcellia griswoldi, sp. nov. and P. lawrencei, sp. nov. receives high nodal support across analytic methods. New combination: Parapurcellia peregrinator (Lawrence, 1963).