A revision of the genus Lomanella Pocock and its implications for family level classification in the Travunioidea (Arachnida: Opiliones: Triaenonychidae)

Abstract

ABSTRACT. Genus Lomanella Pocock, 1903 is redescribed for type species, L. raniceps Pocock, and 18 other species. One new combination is established: L. inermis (Callihamus) (Roewer, 1931). Four species groups are recognised on morphological grounds for the six previously described species and 13 new species: L. raniceps species group comprises L. raniceps, L. atrolutea Roewer, 1915, L. inermis (Roewer, 1931) A key to males is provided. Within the genus, tarsal claws of legs III and IV range from a simple trifurcating claw typical of many triaenonychids, to a complex multiply-branched peltonychium. There is also simplification of penis structure within species of Lomanella. The significance of both claw and penis structure to family level classification in the Travunioidea is discussed and it is shown that a subfamily classification of the Triaenonychidae based on claw morphology is difficult to sustain. Three species are known to inhabit caves including a second totally eyeless triaenonychid. The penis of Nucina silvestris

Tasmanian Trechinae and Psydrinae (Coleoptera, Carabidae): a taxonomic and biogeographic synthesis, with description of new species and evaluation of the impact of Quaternary climate changes on evolution of the subterranean fauna(3)

“…Interestingly, this pattern of troglomorphic adaptation is also suggested in several other invertebrate groups with cave dwelling representatives, including: dalodesmid millipedes (Mesibov 2005); hydrobiid molluscs (Ponder 1992;Ponder et al 2005); triaenonychid harvestmen (Hunt 1990;Hunt & Hickman 1993); synotaxid (Forster et al 1990), amphinectid (Davies 2003) and micropholcommatid (Rix & Harvey 2010) spiders.…”

A stable phylogenomic classification of Travunioidea (Arachnida, Opiliones, Laniatores) based on sequence capture of ultraconserved elements

“…The morphological distinction between the typical trident-shaped tarsal claw (with variable number of side-branches) and a peltonychium is not entirely clear in some travunioids (e.g., Izunonychus , Metanippononychus ), and the transition between forms is best documented in the triaenonychid genus Lomanella Pocock, 1902 (Hunt and Hickman 1993). However, all of the 18 travunioid species (not including subspecies) with a clear peltonychium are found in caves, 10 of which are either described to be troglobitic (cave-obligate) and/or show high levels of troglomorphy.…”

“…It is now widely-recognized that tarsal claw structure is a poor taxonomic character in this clade, as claw structure is highly homoplastic and variable at all taxonomic levels (e.g., Shear 1977, Maury 1988, Hunt and Hickman 1993, Karaman 2005, Shear and Derkarabetian 2008). For example, many travunioids were formerly grouped with the Triaenonychidae, sharing trident-shaped tarsal claw morphology.…”

“…The transfer of all “north temperate triaenonychids” to the Travunioidea was first hinted at by Staręga (1971), proposed based on intestinal morphology by Dumitrescu (1975, 1976), and has since been supported with additional morphological (Giribet and Kury 2007, Mendes 2009) and molecular phylogenetic data (e.g., Derkarabetian et al 2010, Giribet et al 2010, Sharma and Giribet 2011). Other somatic morphological characters have been used to diagnose travunioid taxa (e.g., free lateral sclerites), but these characters may be retained plesiomorphic states (Kury 2007a) and/or potentially neotenic (Rambla 1980, Hunt and Hickman 1993). To illustrate the difficulty in the using these characters specifically in travunioids, Karaman (2005) described the monotypic genus Trojanella Karaman, 2005 yet left it unplaced within Travunioidea due to the uncertainty and homoplasy surrounding the diagnostic characters typically used to assign travunioid taxa.…”

Cave fauna monitoring and management at Ida Bay, Tasmania

“…About 100 species of invertebrate are recorded including at least 15 species of which are obligate cave inhabitants, or troglobites (Harrison, 1966;Hickman, 1958;Hunt, 1990;Hunt and Hickman, 1993;Lea, 1910;Moore, 1967Moore, , 1972Richards, 1964Richards, , 1972. Conservation threats to the Ida Bay karst include limestone quarrying and human visitors to caves.…”