Revision of the old world Holothyridae (Arachnida : Anactinotrichida : Holothyrina)

Abstract

A revised classification of the Holothyridae is presented. The family is restricted to archipelagoes from Melanesia to the Seychelles, with no known records from any continent. Evolution of holothyrid characters, phylogenetic relationships of the eight holothyrid genera and criteria for taxonomic categories in Holothyridae are discussed.

Holothyrus braueri Thon, 1905, from the Seychelle Islands, is selected as the type species of a new genus, Sternothyrus. A new genus, Lindothyrus, is created for L. rubellus, sp. nov., from the western coast of New Caledonia, and L. elongatus, sp. nov., from Lord Howe Island, Australia. Indothyrus greeni, gen. et sp. nov., is described from Sri Lanka.

Hammenius (Leiothyrus) Hammen, 1983 is raised to generic rank and Holothyrus nitidissimus Thorell, 1882 from the Fly River, and H. armatus Canestrini from Tamara Island (Aitape), both New Guinea, are included in this genus. The two previously known New Guinean genera, Thonius Lehtinen, 1981 and Hammenius Lehtinen, 1981, are redefined and relimited, and their type species are redescribed. Five new holothyrid taxa are described from New Guinea: Thonius mendi from the Strickland River, T. berlesei from an unknown locality, Hammenius fujuge iora from the Central district, Oro Province, H. grandjeani gressitti from Mt Bosavi, and H. insularis from the Louisiade Archipelago.

Holothyrus Gervais, 1842 is restricted to two species from Mauritius only. A new genus, Haplothyrus, is created for the New Caledonian species H. expolitissimus Berlese, 1924 and for H. hyatti, sp. nov., from an unknown locality. Haplothyrus is characterised by the possession of a single female genital valve instead of four valves, as in all other genera of this suborder. The poorly described Seychellian species with no preserved material could not be revised.