Cladistics
Cladistics 25 (2009) 231–262 10.1111/j.1096-0031.2009.00249.x
Higher-level phylogenetics of linyphiid spiders (Araneae, Linyphiidae) based on morphological and molecular evidence
Miquel A. Arnedoa,*, Gustavo Hormigab and Nikolaj Scharff c
aDepartament Biologia Animal, Universitat de Barcelona, Av. Diagonal 645, E-8028 Barcelona, Spain; bDepartment of Biological Sciences, The George Washington University, Washington, DC 20052, USA; cDepartment of Entomology, Natural History Museum of Denmark, Zoological Museum, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark Accepted 19 November 2008
Abstract
This study infers the higher-level cladistic relationships of linyphiid spiders from five genes (mitochondrial CO1, 16S; nuclear 28S, 18S, histone H3) and morphological data. In total, the character matrix includes 47 taxa: 35 linyphiids representing the currently used subfamilies of Linyphiidae (Stemonyphantinae, Mynogleninae, Erigoninae, and Linyphiinae (Micronetini plus Linyphiini)) and 12 outgroup species representing nine araneoid families (Pimoidae, Theridiidae, Nesticidae, Synotaxidae, Cyatholipidae, Mysmenidae, Theridiosomatidae, Tetragnathidae, and Araneidae). The morphological characters include those used in recent studies of linyphiid phylogenetics, covering both genitalic and somatic morphology. Different sequence alignments and analytical methods produce different cladistic hypotheses. Lack of congruence among different analyses is, in part, due to the shifting placement of Labulla, Pityohyphantes, Notholepthyphantes, and Pocobletus. Almost all combined analyses agree on the monophyly of linyphioids, Pimoidae, Linyphiidae, Erigoninae, Mynogleninae, as well as Stemonyphantes as a basal lineage within Linyphiidae. Our results suggest independent origins of the desmitracheate tracheal system in micronetines and erigonines, and that erigonines were primitively haplotracheate. Cephalothoracic glandular specializations of erigonines and mynoglenines apparently evolved independently. Subocular sulci of mynoglenines and lateral sulci (e.g. Bathyphantes) evolved independently but glandular pores in the prosoma proliferated once. The contribution of different character partitions and their sensitivity to changes in traditional analytical parameters is explored and quantified. The Willi Hennig Society 2009.
Introduction are linyphiids; Scharff and Gudik-Sørensen, 2006). In the tropics, linyphiids can also be diverse (Scharff, Linyphiids are the most speciose family-level lineage 1990a, 1992; Miller, 2007) but they represent a much of araneoid spiders, a large clade that includes, among smaller fraction of the total spider diversity (Scharff, others, the ecribellate orbweavers (Griswold et al., 1998) 1990b, 1992, 1993; Silva and Coddington, 1996; and close to 30% of the total described species diversity Sørensen et al., 2002; Floren and Deeleman-Reinhold, of spiders (Platnick, 2008) (Fig. 1). Although linyphiids 2005). Most linyphiid species are generalist predators have a worldwide distribution, they are most diverse in and build aerial or substrate webs to capture their prey. north temperate and colder regions. At higher latitudes Linyphiid webs are often built as a sheet, with various they account for a large fraction of the spider species elaborations such as an upper and lower scaffolding (or richness (e.g. 216 of the 523 spider species in Denmark none at all) (Fig. 2), although only a very few detailed descriptions of their webs exist in the literature (Benja- *Corresponding author: min and Zschokke, 2004; Hormiga, 2007). Compared E-mail address: [email protected] with other araneoid lineages, such as the members of the