Out of the twilight zone: phylogeny and evolutionary morphology of the orb-weaving spider family Mysmenidae, with a focus on spinneret spigot morphology in symphytognathoids (Araneae, Araneoidea) Author Lopardo, Lara Author Hormiga, Gustavo text Zoological Journal of the Linnean Society 2015 2015-02-16 173 3 527 786 http://dx.doi.org/10.1111/zoj.12199 journal article 123829 10.1111/zoj.12199 02f79ff2-493a-449e-8206-5662abfa5c52 0024-4082 5331625 MYSMENINAE PETRUNKEVITCH, 1928 (CLADE C133) Composition This morphologically distinct subfamily is circumscribed here to comprise the following genera: Anjouanella , Brasilionata , Calodipoena , Calomyspoena , Itapua , Kekenboschiella , Microdipoena , Mysmena , Mysmenella , Mysmeniola , and Tamasesia [ Fig. 160 , see below and refer to Fig. 161B for synonymies, see below for comments on recently erected Chinese genera not included in the analyses; see main text for the removal and suggested new familial status of Crassignatha , Iardinis , Leviola , and Phricotelus ; see Miller et al . (2009) for the removal of Crassignatha based on morphology; and see Rix & Harvey (2010) for the transfer of Taphiassa to Micropholcommatinae and its synonymy with Parapua ]. In our phylogenetic analyses, Mysmeninae included the following taxa: Microdipoena , Mysmeniola , Brasilionata , Mysmena (see below for total number of species and generic composition), and the following undescribed species (regarded here as Mysmeninae incertae sedis ): MYSM-001-MAD, MYSM-006-MAD, MYSM-008-ARG, MYSM-009-MAD, MYSM-012-MAD, MYSM-019-MAD, MYSM-020-MAD, MYSM-021-MAD, MYSM-023-MAD, MYSM-026- MAD, MYSM-027-MAD, MYSM-029-MAD, MYSM-031-MAD, MYSM-032-MAD, and MYSM-033-MAD. Monophyly Relationships within Mysmeninae are unstable, except for a few taxa (see below). The following synapomorphies support Mysmeninae as we have circumscribed it: respiratory system with anterior tracheae restricted to opisthosoma ( Fig. 37A ; extending into prosoma in MYSM-005-ARG, MYSM-007- MEX , and Microdipoena s.s. ); advanced and wide posterior spiracular opening located midway between the spinnerets and epigastric groove ( Fig. 24A, E ), connected to branched posterior lateral tracheae extending into prosoma ( Fig. 22A, B ); aciniform gland spigots of posterior spinnerets with two different outlines ( Figs 19F , 33D , 37 ,B E); posterior lateral spinnerets with an anterior flat spatulate modified seta [ Figs 23B, E , 33G, H , 52C ; secondarily absent in Mysmena (= Tamasesia ) rotunda ], and slim cylindrical spigots ( Figs 23B , 37B, E ); palpal tibial trichobothria of females lacking ( Figs 38E , 52E ); female copulatory openings within the epigastric furrow ( Fig. 24A ; secondarily external in MYSM-023-MAD), membranous atrium ( Figs 129A, E, G , 130B ), and irregular membranous copulatory ducts ( Figs 18G , 27D , 129A–C, E, H , 130A– G ; distally sclerotized independently in two clades); males with coiled embolus ( Figs 27A , 47A, B , 132D, E , 134G ) and secondary (external) cymbial conductor ( Figs 31C , 40A , 43C ; secondarily absent in clade C128: Microdipoena , Brasilionata , Mysmeniola , and MYSM-019-MAD; Fig. 22F ). Other synapomorphies include: abdomen with a whitish ventral ring surrounding the spinnerets ( Figs 142J, L , 143A, B, G, I, L ), trichobothria on tibia III and IV between two and three tibia diameters in length ( Figs 26G , 29E , 39G ; short trichobothria occurs independently within the group), and strongly serrated distal promarginal curved seta ( Figs 19E , 38H , 42E , 48B ). Ambiguously optimized synapomorphies for this clade include: a posterior tracheal arrangement consisting of lateral tracheae surrounding the minute median apodemes ( Fig. 29B ); fingerprint cuticular pattern on the piriform field ( Figs 23A, C , 33E ); flagelliform spigots absent in males ( Fig. 23E ; secondarily present in Mysmena leichhardti and MYSM-005-ARG); orb webs with a proliferation of out-of-plane radii both above and below the orb plane ( Fig. 147A, B ); males with prolateral row of slim setae occupying only distal half of tarsus I ( Figs 16H , 26A , 34D , 45I , 50F ; all along tarsus in Mysmeniola spinifera ); cymbial prolateral basal expansion ( Figs 27A , 30B, C , 36C , 47B ); embolus with pars pendula ( Figs 32H , 36B , 132C–F , 133C , secondarily absent in MYSM-005- ARG); palpal tibial rim setae longer and arranged distally in a row or two [ Figs 18A , 32E , 36D , 42B , 45C ; secondarily irregular in Mysmeniola spinifera and Microdipoena (= Mysmenella ) jobi ]; and females with weakly modified epigynal area (i.e. epigynum absent; Figs 14C , 37A , 52F ; modified copulatory area in MYSM-023-MAD, Fig. 49D, E ). A total of 163 molecular synapomorphies support this subfamily. Diagnosis Mysmeninae differs from all other mysmenid genera and subfamilies by the following unique combination of features: the characteristic architecture of their orb webs with a proliferation of out-of-plane radii both above and below the orb plane; anterior tracheae restricted to opisthosoma (extending into prosoma in MYSM-005-ARG, MYSM-007- MEX , and Microdipoena s.s. ), and an advanced and wide posterior spiracular opening located midway between the spinnerets and epigastric groove, connected to branched posterior lateral tracheae extending into prosoma and surrounding the minute median apodemes; anterior lateral spinnerets with fingerprint cuticular pattern on the piriform field, posterior spinnerets with aciniform gland spigots of two different outlines, and posterior lateral spinnerets with an anterior flat spatulate modified seta [as in Maymena , secondarily absent in Mysmena (= Tamasesia ) rotunda ], slim cylindrical spigots, and flagelliform spigots absent in males (secondarily present in males of Mysmena leichhardti and MYSM-005-ARG); females without epigynum and with the copulatory openings within the epigastric furrow (secondarily external in MYSM-023- MAD), a membranous internal atrium and irregular membranous copulatory ducts (distally sclerotized independently in two clades); males with secondary (external) cymbial conductor (secondarily absent in clade C128: Microdipoena , Brasilionata , Mysmeniola , and MYSM-019-MAD), cymbial prolateral basal expansion, coiled embolus with pars pendula (secondarily absent in MYSM-005-ARG), palpal tibial rim setae long and arranged distally in a row or two [secondarily irregular in Mysmeniola spinifera and Microdipoena (= Mysmenella ) jobi ], a prolateral row of slim setae occupying only distal half of tarsus I (all along tarsus in Mysmeniola spinifera ); and also a strongly serrated distal promarginal curved seta, abdomen with a whitish ventral ring around the spinnerets, trichobothria on tibia III and IV of medium length.