Megalostrata Karsch 1880
Creators: name: Bonaldo, Alexandre B.
name: Galán-Sanchez, M. Antonio
name: García, Fabián
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Corinnidae
Megalostrata

description: Megalostrata Karsch, 1880
Megalostrata Karsch, 1880: 377;
type species by monotypy, M. venifica Karsch, 1880 [
synonymized with Megalostrata raptor (L. Koch, 1866) by Bonaldo (2000)]. For a complete list of synonyms see Bonaldo (2000: 116).
Diagnosis. Megalostrata appears to be most closely related to Erendira Bonaldo, 2000 with which it shares a prolateral tegular process that is apical in relation to the embolus insertion (Figs 3A, C, 20A, B, 22A, B; Bonaldo 2000: figs 110–113, 304, 314) and the epigynum with an unsclerotized dorsal vulval plate and highly modified posterior plate (Figs 5C, 8C, 12C, 22D; Bonaldo 2000: figs 309, 323). Erendira also have dimorphic chelicerae, being longer in males than in females, but the male chelicerae of Erendira are not as modified as in Megalostrata (Figs 1, 2, 4A, C, 15A, C; see also Bonaldo 2000: figs 303, 312). Representatives of Megalostrata are readily separated from those of Erendira by presenting porrect male chelicerae, with only two large retromarginal teeth (Figs 2B, 17B; Bonaldo 2000: fig. 303) (male chelicerae not porrect, with three to four unmodified retromarginal teeth in Erendira), male palpal tegulum without a conductor and with a highly coiled spermatic duct (Figs 3A, C, 20, 22A, B) (hyaline conductor and uncoiled spermatic duct, with terminal portion adjacent to the second fold in Erendira, see Bonaldo 2000: figs 314, 320); female epigynum with posterior plate excavated medially, exposing the unsclerotized cuticle of the epigastric plate (Figs 5C, 6E, 8C, 9E, 12C, 13E, 22D, 24C) (posterior plate not medially excavated, with a pair of accessory lateral pockets in Erendira, see Bonaldo 2000: figs 317, 323). Species of Megalostrata also have a distinctive body color pattern, generally with contrasting stripes on the carapace, and yellowish-white and black patches or lines on the abdomen of both sexes, features that are easily visible in living specimens (Fig. 1).
Description. See Bonaldo (2000: 116).
Key to species of Megalostrata
1 Males [Those of M. monistica (Chamberlin, 1924), M. bruneri (Bryant, 1936) and M. pacifica spec. nov. unknown]....... 2
- Females............................................................................................. 4
2(1) Retrolateral tibial apophysis bifid (Figs 3C, D; Bonaldo 2000: figs 310, 311)...... M. depicta (O. Pickard-Cambridge, 1895)
- Retrolateral tibial apophysis entire (Figs 3A, B, 20A, 22A, B; Bonaldo 2000: figs 304–306).......................... 3
3(2) Apex of tegular process rounded, devoid of teeth; embolus directed retro-basally (Figs 3A, B; Bonaldo 2000: figs 304–306)................................................................................ M. raptor (L. Koch, 1866)
- Apex of tegular process truncated, with small teeth; embolus directed retro-apically (Figs 20, 22A, B, 23A, B)............................................................................................. M. paludosa spec. nov.
4(1) Secondary spermathecae elongated, tube-shaped (Figs 5A, B, 6A–D, 8A, B, 9A–D; Bonaldo 2000: fig. 309)............. 5
- Secondary spermathecae bulbous (Figs 12A, B, 13A–D, 14C, 22C, E, 23C, D, 24A, B).............................. 7
5(4) Secondary spermathecae oriented obliquely (Figs 5A, B, 6A–D; Bonaldo 2000: figs 308, 309)........................ 6
- Secondary spermathecae oriented longitudinally (Figs 8A, B, 9A–D)........................... M. pacifica spec. nov.
6(5) Posterior atrium defined by a transversal anterior ridge at the level of copulatory openings (Bonaldo 2000: fig. 308)....................................................................................... M. raptor (L. Koch, 1866)
- Posterior atrium borders ill-defined, transversal anterior ridge absent (Figs 5A, B, 6A–D)................................................................................................ M. depicta (O. Pickard-Cambridge, 1895)
7(4) Copulatory openings wide, leading to long, curved anteriorly copulatory ducts; posterior margin of epigynal plate with a median invagination (Figs 10C, 12A, 13A, C)..................................... M. monistica (Chamberlin, 1924)
- Copulatory openings inconspicuous, copulatory ducts short; posterior margin of epigynal plate without median invagination (Figs 14C, 22C)...................................................................................... 8
8(7) Primary spermathecae small (diameter near the atrium height), positioned anteriorly to posterior atrium (Fig. 14C)........................................................................................ M. bruneri (Bryant, 1936)
- Primary spermathecae large (diameter larger than the atrium height), positioned at the level of posterior atrium (Figs 22C, 23C, 24A, B)........................................................................... M. paludosa spec. nov.
description: Published as part of Bonaldo, Alexandre B., Galán-Sanchez, M. Antonio & García, Fabián, 2024, Advances on the taxonomy of Megalostrata Karsch, 1880 (Araneae, Corinnidae, Corinninae), with descriptions of two new species, pp. 495-523 in Zootaxa 5458 (4) on pages 496-497, DOI: 10.11646/zootaxa.5458.4.2, http://zenodo.org/record/11547908