Hiatomegops GUO ET AL. 2022, gen. nov.
Creators: name: Guo, Xiangbo
name: Selden, Paul A.
name: Ren, Dong
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Lagonomegopidae
Hiatomegops

description: GENUS HIATOMEGOPS GUO ET AL. gen. nov.
Zoobank registration: u r n: l s i d: z o o b a n k. org:act: F0561F03-E69D-45E6-A7FB-4A4D3BFEC6EE
Etymology: The genus name is the combination of hiatus, opening in Latin, after the broad tracheal spiracle behind the epigastric furrow, and Lagonomegops, type genus of the family, from Greek -μεγόψ, magnification. The name is masculine.
Type species: Hiatomegops spinalis sp. nov.
Diagnosis: Palpal tibia and tarsus with several dorsal trichobothria; leg metatarsus slightly longer than tarsus; broad tracheal spiracle situated on postgastric area behind epigastric furrow.
Remarks: Finding a fossil spider species in which both males and females have been described is rare. Among 19 reported genera in Lagonomegopidae, only Archaelagonops Wunderlich, 2012 is known from both male and female specimens. The two female specimens, which were subsequently included in Archaelagonops (erected on a male specimen originally), lack sufficient evidence to belong in that genus (Wunderlich, 2012, 2015). In general, female spiders are a larger size than conspecific males. Four lagonomegopid species, Lineaburmops beigeli, Lineaburmops maculatus Wunderlich, 2015, Parviburmops brevipalpus Wunderlich, 2015 and Planimegops parvus Wunderlich, 2017, comprised only of male specimens, were described as having a similar or smaller size with CNU-ARA-MA2020002, an adult female. CNU-ARA-MA2020002 can be distinguished from them by: carapace without white patch (carapace with distinct white patches in Lineaburmops beigeli and Lineaburmops maculatus); carapace much longer than wide (carapace length equal with width in Parviburmops brevipalpus); cephalic region of carapace with a pair of anterolateral protrusions next to the inner side of PME (protrusions absent in Planimegops parvus). We erected a new genus Hiatomegops based on CNU-ARA-MA2020002. Hiatomegops can be distinguished from the other two lagonomegopid genera (Lagonoburmops and Picturmegops) comprised only of female specimens by: body length 2.89 (body length about 8.00 in Lagonoburmops); carapace piriform in outline, much longer than wide (carapace distinctly narrowed posteriorly, slightly wider than long in Picturmegops); carapace without a stripe (carapace with distinct stripes in Picturmegops); metatarsus of leg I slightly longer than tarsus (metatarsus of leg I about two times longer than tarsus in Lagonoburmops).
In addition, the holotypes of Grandoculus chemahawinensis Penney, 2004,? Lagonomegops cor Pérez-de la Fuente et al., 2013, Soplaogonomegops unzuei Pérez-de la Fuente et al., 2013, Spinomegops aragonensis Pérez-de la Fuente et al., 2013 and Spinomegops arcanus Pérez-de la Fuente et al., 2013 were identified as ‘juvenile or adult female’ (Penney, 2004; Pérez-de la Fuente et al., 2013). Hiatomegops can be easily separated from these by: carapace piriform in outline, without neck (carapace heart-shaped when viewed from above in? Lagonomegops cor; cephalic region constricted in a neck, with narrowest point medially in Soplaogonomegops unzuei), fovea small oval, deeply depressed (fovea absent in Spinomegops aragonensis and Spinomegops arcanus), leg I not enlarged, metatarsus and tarsus without scopulae (leg I distinctly longer and more robust than the others, metatarsus and tarsus with scopulae hairs in Grandoculus chemahawinensis).
description: Published as part of Guo, Xiangbo, Selden, Paul A. & Ren, Dong, 2022, New specimens from Mid-Cretaceous Myanmar amber illuminate the phylogenetic placement of Lagonomegopidae (Arachnida: Araneae), pp. 399-416 in Zoological Journal of the Linnean Society 195 on pages 404-406, DOI: 10.1093/zoolinnean/zlab027, http://zenodo.org/record/6599779