Family ties: molecular phylogeny of crab spiders(Araneae: Thomisidae)Suresh P. Benjamina,b*, Dimitar Dimitrova, Rosemary G. Gillespieband GustavoHormigaaaThe George Washington University, Department of Biological Sciences, 2023 G Street NW, Washington DC, 20052, USA;bUniversity of California,Berkeley, Insect Biology Division—ESPM, 201 Wellman Hall 3112, Berkeley, CA 94720-3112, USAAccepted 2 November 2007AbstractThe first quantitative phylogenetic analysis of three sequenced genes (16S rRNA, cytochrome c oxidase subunit I, histone 3) of 25genera of crab spiders and 11 outgroups supports the monophyly of Thomisidae. Four lineages within Thomisidae are recovered.They are informally named here as the Borboropactus clade, Epidius clade, Stephanopis clade and the Thomisus clade, pendingdetailed morphology based cladistic work. The Thomisus clade is recovered as a strongly supported monophyletic group with aminimal genetic divergence. Philodromidae previously widely considered a subfamily of Thomisidae do not group within thomisidsand is excluded from Thomisidae. However, Aphantochilinae previously generally considered as a separate family falls within theThomisus clade and is included in Thomisidae. The recently proposed new family Borboropactidae is rejected, as it is paraphyletic. The Willi Hennig Society 2008.Thomisidae Sundevall, 1833, commonly called crabspiders are often cryptically colored sit-and-wait preda-tors that do not build capture webs (Fig. 1). Thomisidaeis the sixth largest spider family. It includes 2062described species in 171 genera (Platnick, 2007) withmany more species remaining to be descri bed. They aremainly active during the day and ambush insects withtheir well-adapted first and second legs (Homann, 1934;Comstock, 1948). Not surprisingly, they are an impor-tant component of terrestrial ecosystems (Riechert,1974). As predators of agricultural pests, thomisids playan important part in natural pest control (Riechert andLockley, 1984; Nyffeler and Benz, 1987; Uetz et al.,1999).Some thomisids (e.g., M isumena, Diaea, Runcinia andThomisus) possess the ability to change color and blendinto their habitat, in most cases flowers (Packard, 1905;Gabritschevsky, 1927; Comstock, 1948). Misumena vatia(Clerck, 1757) has a remarkable ability to change color,which takes place during migration to flowers ofdifferent color from spring to the early part of summer(Comstock, 1948). Crab spiders are attracted by fra-grance components of flowers (Aldrich and Barros,1995; Krell and Kraem er, 1998) and use visual andtactile cues for selecting flowers (Morse, 1988; Grecoand Kevan, 1994). They reach their ambush sites in astep-by-step process using several draglines and bal-looning events (Homann, 1934).There are social crab spiders with maternal care in theEucalyptus forest of Australia (Main, 1988; Evans,1995). Mother Diaea ergandros Evans (1995), catchlarger prey for their own offspring, but not for theadopted offspring leading to large size and possiblybetter survival rates for the natural offspring (Evans,1998). Mothers further increase survival of naturaloffspring by producing trophic oocytes used in a systemof sacrificial care (Evans, 1998).Myrmecomorphism is known in a number of thomis-ids: Strigoplus albostriatus Simon, 1885, Amyciaeaforticeps (O.P.-Cambridge, 1873), A. lineatipes*Corresponding author:E-mail address: [email protected]Present address: Department of Entomology, National Museum ofNatural History NHB 105, PO Box 37012, Smithsonian Institution,Washington, DC 20013-7012, USA. The Willi Hennig Society 2008Cladistics 24 (2008) 708–722Cladistics10.1111/j.1096-0031.2008.00202.xO.P.-Cambridge, 1901 and Aphantochilus rogersiO.P.-Cambridge, 1870, are known to be ant mimics.A. forticeps is of the same color as the ant Oecophyllasmaragdina and bears on the posterior part of theabdomen a pair of eye-like spots that correspond to eyesof the ant (Shelford, 1902). The similarity of A. rogersiito some spiny South American ants is striking, andforms a further instance of myrmecomorphism (Oliveiraand Sazima, 1984).Given their ecological significance and appealingadaptations one would expect to see a plethora ofphylogenetic studies. However, no such studies ofthomisids exist. Moreover, understanding the exacttaxonomic limits of this large family has always beenproblematic. Thomisidae was proposed to accommo-date spiders with legs generally extended sideways(laterigrade), instead of being oriented towards the frontor back as in most other spiders. Originally all spiderswith laterigrade legs such as Sparassidae and Philodr-omidae were included. Simon (1892) was the first topropose a hypothesis of generic groups for all thomi sidgenera recognized during his time. Although his‘‘groups’’ were neither evolutionary nor phylogeneticin the modern sense, he provided some information onThomisidae morphology and arguments supporting hisideas. His Stephanopsinae contained spiders with che-liceral teeth; Aphantochilinae and Strophiinae con-tained species wi th modifications such as elongatedmaxillae related to their ant mimicking habits; Stiphro-podinae included species with an enlarged tarsus; spidersthat did not fit into the above categories were includedin Misumeninae and Philodrominae. Species groupswere then formed within these subfamilies based on eyepattern and shape of prosoma.Since Simon (1892) the understanding of genericrelationships has not changed great ly. Holm (1940), onthe grounds of embryological studies, and Homann(1975), on the grounds of eye morphology, excludedPhilodromids from Thomisidae. Philodromids werelater given family status (Ono, 1988), which has beenaccepted since (but see Roberts, 1995). Sep arately,family status was proposed for some thomisids, Steph-anopidae (Pickard-Cambridge, 1871) and Aphantochi-lidae (Thorell, 1873). Levi (1982) placed the Thomisidaein a superfamily along with Aphantochilidae, which wasnot accepted by Ono (1988). In the most current studyThomisidae was separated into seven subfamilies (Ono,1988): Stephanopinae, Thomisinae, Bominae, Stiphr o-podinae, Dietinae, Strophiinae and Aphantochilinaeusing characters proposed by Simon (1892). Recently(Wunderlich, 2 004b) proposed a new family ‘‘Borborop-actidae’’ to include parts of Thomisidae. Thus, to date,the monophyly of Thomisidae remains untested.A great part of our knowledge of evolutionary historyis derived from phylogenies, reconstructed