Isela Griswold 1985
Creators: name: Lopardo, Lara
name: Hormiga, Gustavo
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Mysmenidae
Isela

description: ISELA GRISWOLD 1985
(FIGS 1–9, 128A, C, 131D, G, H, 140A–F: CLADE C158)
Isela Griswold, 1985: 208.
Kilifina Baert & Murphy, 1992: 104 (replacement name for Kilifia Baert & Murphy, 1987: 194, preoccupied; type species by monotypy Kilifia inquilina Baert & Murphy, 1987, paratype material in IRSN and MRAC, examined). New synonymy.
Type species
Isela okuncana Griswold 1985 by original designation and monotypy, type material in NMSA and CAS, examined.
Synonymy justification
Both of these African monotypic genera share extremely peculiar male and female genitalia (see Figs 128A, C, 131D, G, H), form a clade in all morphological and combined analyses, and share several other morphological synapomorphies. The type material of both species have been examined as well as a third of undescribed species from Kenya, and the conformation of the genital morphology remains consistent across all of them.
Familial placement and composition
Isela is sister to Mysmenopsis within the subfamily Mysmenopsinae (Fig. 161B). Currently, and as defined here, the genus Isela comprises two species (I. okuncana and I. inquilina comb. nov.), and is here represented by one described plus one undescribed species: I. okuncana and Kilifina- MYSM-002- KENYA.
Synapomorphies
Morphological synapomorphies of Isela include: females with coiled tubuliform spermathecae (Figs 5D, 128A, C) and without flagelliform gland spigots (Fig. 6D); both sexes with median trichobothria on metatarsus I (Fig. 8A); and males with secondary external cymbial conductor (Fig. 4G); internal cymbial tarsal organ (Fig. 4I); coiled embolus (Figs 4H, 131H); and two or more prolateral tibial trichobothria on male palp (Figs 1B, 4E). Ambiguously optimized synapomorphies for this genus include: posterior respiratory system with median and single lateral tracheae (Fig. 5E); males with twisted metatarsal clasping spine (Figs 3B, 8B, C, 140E, F); epiandrous fusules dispersed in a row; palpal tibial bearing spine-like strong setae (Figs 1A, B, 4A, E); a prolateral apical secondary cymbial conductor (Fig. 4G, F); and a row of small setae on cymbial fold (Fig. 4G).
Diagnosis
Isela differs from all other mysmenid genera by the spine-like strong setae on male palpal tibial, a secondary cymbial conductor located prolaterally– apically; females without flagelliform gland spigots and with coiled tubuliform spermathecae; posterior median and single lateral tracheae; and trichobothrium located medially on metatarsus I. In addition, the following combination of male features is unique for Isela: twisted metatarsal clasping spine; internal cymbial tarsal organ; a row of small setae on cymbial fold; coiled embolus; and epiandrous fusules dispersed in a row. Originally, Isela was diagnosed by the carapace depression separating the posterior median eyes (PME) from the anterior eye row (AER); the male palpal tibia large, cup-shaped, and with stout dorsoapical spines; by the morphology of cephalothorax; and by the general morphology of male and female genitalia (Griswold, 1985). Baert & Murphy (1987) also noted the general resemblance of Kilifina with Isela in terms of carapace morphology, the separation of the PME from the AER, and the swollen femora I, but stated that the differences between these two genera were based on the male palpal morphology, which were diagnostic for Kilifina. As the male and female genitalia of these two species are identical in their general morphology, the differences between them are here attributed to be at species, and not generic, level. Interestingly, the only diagnostic feature shared between the current and the previous diagnoses for Isela (including Kilifina) are the strong setae on the male palpal tibia. Remaining characteristics are shared in varying degrees with other mysmenid genera, and are not diagnostic of the genus.
description: Published as part of Lopardo, Lara & Hormiga, Gustavo, 2015, 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), pp. 527-786 in Zoological Journal of the Linnean Society 173 (3) on page 780, DOI: 10.1111/zoj.12199, http://zenodo.org/record/5331625