Phylogenetic relationships within Philodromidae, with a taxonomic revision of Philodromus subgenus Artanes in the western Palearctic (Arachnida:Araneae)

Abstract

The first quantitative phylogenetic analysis within the spider family Philodromidae (using 65 morphological characters from 40 ingroup taxa) does not corroborate Schick’s division into the tribes Thanatini (Apollophanes O. P.-Cambridge, 1898, Pelloctanes Schick, 1965, Thanatus C. L. Koch, 1837; Tibellus, Simon, 1875) and Philodromini (Ebo Keyserling, 1884, Philodromus Walckenaer, 1826; Rhysodromus Schick, 1965). Instead, Ebo is sister to all other genera in the family, and a fraction of Philodromus (the histrio species-group = Rhysodromus Schick) are contained with the Thanatini. The forgotten genus Artanes Thorell, 1870 constitutes a well-defined distal taxon in a clade that contains the majority of Philodromus species. Here Artanes is considered a subgenus of Philodromus, and includes the margaritatus and the poecilus species-groups. The western Palearctic species of the subgenus are revised. Twelve species are (re-)described, keyed and illustrated: Philodromus blanckei (Wunderlich, 1995) (first description of ♀); P. calidus Lucas, 1846; P. femurostriatus, sp. nov. from the eastern Mediterranean; P. fuscomarginatus (De Geer, 1778); P. johani, sp. nov. from Crete; P. laricium Simon, 1875, removed from synonymy with P. corticinus (C. L. Koch); P. maghrebi, sp. nov. from northern Africa (♀ only); P. margaritatus (Clerck, 1757); P. parietalis Simon, 1875; P. pentheri, sp. nov. from the Caspian region and Albania (♀ only); P. pinetorum, sp. nov. from the Mediterranean; and P. poecilus (Thorell, 1872).

The Ebo-like running crab spiders in the Old World (Araneae, Philodromidae)

“…However, the leg spination pattern is strikingly diff erent, with Titanebo resembling Rhysodromus (the Philodromus histrio group) and Halodromus gen. n. Ebo and Titanebo are also diff erent in the structure of the female genitalia and in some morphometric indices (Table 1). In none of the phylogenetic analyses performed by Muster (2009) did Titanebo emerge as sister to Ebo. In conclusion, Titanebo clearly deserves generic re-establishment.…”

“…Th e histrio group in its current limits is most likely an artifi cial assemblage of superfi cially similar species. A recent cladistic analysis within Philodromidae (Muster 2009) has shown that histrio and related species are more closely related to the Th anatini (Th anatus and Tibellus) than to other Philodromus species groups. Th us, Rhysodromus clearly deserves re-elevation to genus rank, but the urgently required revision of the histrio group from a phylogenetic perspective is beyond the scope of this study.…”

“…Glandular heads are treated as synonymous with spermathecal organs. As the use of the term "Bursa copulatrix" has been controversial in the past, I here applied a rigid defi nition as proposed by Muster (2009): the "bursa copulatrix" is a canal or three-dimensional region of the vulva that is passed by the embolus during copulation before it enters the receptacula and that is not connected with the duct leading to the glandular heads. If the intromittent canal is merged with the ducts of the glandular heads, this structure is called a "copulatory duct".…”

“…Concerning leg spination in Ebo, I found not only the Old World species to be more similar to spiders of the Philodromus histrio group (= Rhysodromus Schick, 1965) than to North American congeners, but also striking diff erences between the Nearctic subgenera Ebo and Titanebo Gertsch, 1933. A fi rst quantitative cladistic analysis of phylogenetic relationships within Philodromidae (Muster 2009) provided further evidence: Ebo emerged as the most basal clade within the family, while Titanebo grouped with Rhysodromus, Old World Ebo and the Th anatini in a clade that was sister to the remaining Philodromus species. Th e aim of this study is a generic revision of the Ebo-like philodromid spiders (those with markedly elongated leg II and enlarged AME) in order to achieve a better concordance of genera with phylogenetic lineages.…”

“…Th is view is corroborated by a thorough examination of the leg spination pattern. Recent comprehensive studies within Philodromidae have shown that leg spination, in particular that of the tibiae and metatarsi, is presumably the most useful morphological criterion for delineation of supraspecifi c taxa in this family (Muster 2009). Concerning leg spination in Ebo, I found not only the Old World species to be more similar to spiders of the Philodromus histrio group (= Rhysodromus Schick, 1965) than to North American congeners, but also striking diff erences between the Nearctic subgenera Ebo and Titanebo Gertsch, 1933.…”