Acroterius Irfan & Bashir & Peng 2021, gen. nov.
Creators: name: Irfan, Muhammad
name: Bashir, Shahida
name: Peng, Xianjin
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Acroterius

description: Acroterius gen. nov.
urn:lsid:zoobank.org:act: EEA7B37A-300B-43D9-87F3-82A380BC686D
Type species
Acroterius brevis gen. et sp. nov.
Diagnosis
Acroterius gen. nov. resembles Diplostyla; Kaestneria Wiehle, 1956; Laetesia Simon, 1908; Laperousea Dalmas, 1917 and Zhezhoulinyphia in: epigyne with parmula, originates from the posterior margin of posterior median plate with a socket ventrally (Fig. 8A–C; Ivie 1969: figs 105–108; van Helsdingen 1972: fig. 8; Millidge 1988: fig. 173; Irfan & Peng 2018: figs 5c–d, 6c–d; Irfan et al. 2019: figs 1–2, 7, 9–10). In the male palp, the distal margin of the radix is semicircular and has teeth as in Laetesia, Laperousea and Zhezhoulinyphia (Figs 6A–C, 7A–B; Millidge 1988: figs 145–146; Irfan et al. 2019: figs 4a–b, d, 5c–e, 6a–b); the embolus and embolic membrane arise from the dorsal side of the distal margin of the radix as in Zhezhoulinyphia (Figs 6A–C, 7A–B; Irfan et al. 2019: figs 4a–b, d, 5c–e, 6a–b). It can be distinguished by the anterior wall of the epigyne which has a posterior projection on each side (Fig. 8A–B), but in species of Laetesia, the posterior arm of the anterior wall of the epigynal plate is long, with a copulatory opening on the posterior ventral end (Millidge 1988: figs 173, 187), and the posterior projection of the anterior wall absent in species of Diplostyla, Kaestneria and Zhezhoulinyphia (van Helsdingen 1972: fig. 8; Millidge 1988: fig. 173; Irfan & Peng 2018: figs 5c–d, 6c–d; Irfan et al. 2019: figs 1–2, 7, 9–10). The spermathecae are situated near the base of the parmula (Fig. 8A–B) in Acroterius gen. nov., but towards the periphery of epigyne in species of Kaestneria, Laetesia and Zhezhoulinyphia (Millidge 1988: figs 187–189; Tao et al. 1995: figs 80–81; Irfan et al. 2019: figs 1–2, 7, 9–10). The cymbium has a cymbial retrolateral lobe (Figs 6B–D, 7B) as in species of Zhezhoulinyphia (Irfan et al. 2019: figs 4b, 5b, g, 6b), but it is absent in Kaestneria and Laetesia (Millidge 1988: figs 143–144; Paquin & Dupérré 2003: figs 1544, 1547). The distal arm of the paracymbium of Acroterius gen. nov. has two or three projections and covers most of the proximal part of paracymbium (Figs 6B–C, 7B), the distal part of the paracymbium of all species of Kaestneria and Laetesia is simple U- or V-shaped and doesn’t cover the proximal part (Millidge 1988: figs 187–189; Paquin & Dupérré 2003: figs 1544, 1547) and there is a large, distal arm longer than wide, tip pendulum-shaped in species of Zhezhoulinyphia (Irfan et al. 2019: figs 4b, 5f, 6b). The distal end of the distal suprategular apophysis of Acroterius gen. nov. and Kaestneria is not notched (Figs 6B–C, 7B; Tao et al. 1995: figs 77–78) (but notched in species of Laetesia, Millidge 1988: fig. 146), and proximally broad with teeth, has a distal part strongly curved into an inversed U-shape, almost touching the distal margin of the paracymbium in species of Zhezhoulinyphia (Irfan et al. 2019: figs 4b, 5b, g, 6b). The tegulum of Acroterius gen. nov. has a small tegular projection ventrally (Figs 6B–C, 7B), which is absent in Kaestneria (Paquin & Dupérré 2003: figs 1544, 1547; Zhao & Li 2014: figs 47b, 49b) and Laetesia (Millidge 1988: fig. 146). The embolic division of Acroterius gen. nov. comprises a distal semicircular part of the radix with a serrated margin anteriorly; the embolus and embolic membrane arise from the terminal part of the radix (Figs 6A–C, 7A–B) as in species of Zhezhoulinyphia (Irfan et al. 2019: figs 4a–b, 5c–e, 6a–b); the embolus and median membrane arise from the lateral (inner) side of the plate in Kaestneria and Laetesia (Millidge 1988: figs 145, 149; Zhao & Li 2014: figs 47b, 49b) whereas in Diplostyla the embolus arises near the base of the cymbium and extends parallel along the full length of cymbium (Ivie 1969: figs 107–108). In Acroterius gen. nov. the proximal end of the radix has a radical apophysis (Figs 6A–C, 7A–B) as in species of Zhezhoulinyphia (Irfan et al. 2019: figs 4a–b, 5c–e, 6a–b), but it is absent in Diplostyla, Kaestneria and Laetesia (Ivie 1969: figs 107–108; Millidge 1988: figs 145, 149; Zhao & Li 2014: figs 47b, 49b).
Etymology
The generic name is an arbitrary combination of letters. Gender masculine.
Description
MEASUREMENTS. Large sized, male total length 2.66–3.61; female total length 2.66–4.15.
HEAD. Cephalic region slightly elevated, yellowish to dark brown; fovea, cervical and radial grooves distinct; sternum longer than wide, green to yellowish to dark brown with spine-like hairs; labium wider than long, dark brown; maxillae long, distal end broader with scopulae. Eye region narrow, AER recurved, PER procurved slightly wider.
LEGS. All legs with annuli; patella of each leg with two spines; chaetotaxy: 2–2–2–2; Tm I and Tm IV present.
ABDOMEN. Oval, dorsally with pattern extending down to the base of spinnerets followed by irregular white patches dorso-laterally, and ventrally pale, greenish to brown with or without irregular white patches (Fig. 4A–B).
MALE PALP (Figs 1, 3, 6, 7, 10–12, 15–16, 24, 26, 30–31). Patella shorter than tibia, dorsally with a long spine;tibia cone shaped, with two retrolateral trichobothria, with some short and long setae on all surfaces; paracymbium highly sclerotized, proximal part simple, somewhat rectangular, distal arm with two to three projections (characterized as lateral, median and ventral projections); cymbium with retrolateral lobe, covered with long thick spines; tegulum with small projection ventrally; distal suprategular apophysis long, basally covered by embolic division. Radix with distal broad semicircular serrated part giving rise to embolus and embolic membrane, at proximal end with small radical apophysis and dorsal projection of embolic plate; dorsal projection of embolic plate long, slightly overlapping cymbium; embolic membrane curved and approachnig distal semicircular part, in prolateral view; embolus stout, short with pointed end.
EPIGYNE (Figs 8, 13, 17, 21A–D, 22, 27, 29A–D, 32, 34B–E, 36A–D, 37). Anterior wall of epigyne wider than long; posterior margin of anterior wall with a projection on each side; copulatory openings situated inside the atrium between the anterior wall and posterior median plate, connected with long, semicircular copulatory ducts joined to the spermathecae. Posterior median plate posteriorly with a parmula of variable length with a socket ventrally. Spermathecae slender, present near the posterior median plate. Fertilization ducts long, present laterally on the posterior median plate, extending mesally.
Distribution
China (Yunnan Province, Figs 38–39).
description: Published as part of Irfan, Muhammad, Bashir, Shahida & Peng, Xianjin, 2021, Acroterius gen. nov. (Araneae: Linyphiidae: Linyphiinae) with twelve new species from Yunnan, China, pp. 1-53 in European Journal of Taxonomy 743 on pages 3-5, DOI: 10.5852/ejt.2021.743.1293, http://zenodo.org/record/4664312