New specimens from Mid-Cretaceous Myanmar amber illuminate the phylogenetic placement of Lagonomegopidae (Arachnida: Araneae) Author Guo, Xiangbo Author Selden, Paul A. Author Ren, Dong text Zoological Journal of the Linnean Society 2022 2021-06-16 195 399 416 https://www.mendeley.com/catalogue/e9144677-a36a-374f-9b9f-ef35c5f8cd3c/ journal article 61601 10.1093/zoolinnean/zlab027 507433fb-c54c-4c3a-9872-748cd6417b9d 0024-4082 6599779 GENUS SCOPOMEGOPS GUO ET AL . gen. nov . Zoobank registration : urn: lsid: zoobank. org:act: A8809BE3-D927-432B-9C04-0AC83C27391F Etymology: The genus name is the combination of scopa , broom in Latin, after the clustered clavate spicules on the palpal retrolateral tibial apophysis (RTA), and the Greek suffix -μεγόψ, magnification, from Lagonomegops , type genus of the family. The name is masculine. Type species: Scopomegops fax sp. nov. Diagnosis: Male palpal tibia with a small apophysis on the distal retrolateral surface, several clustered clavate spicules situated on the top of retrolateral apophysis; leg metatarsus distinctly much longer than tarsus. Remarks: CNU-ARA-MA2 0 2 0 0 0 1 is an adult male. It can be easily distinguished from other male lagonomegopids by the apophysis on the distal retrolateral surface of the male palpal tibia. It cannot be included in the two lagonomegopid genera ( Lagonoburmops Wunderlich, 2012 and Picturmegops Wunderlich, 2015 ) comprised only of female specimens, because of: carapace piriform in outline, much longer than wide (carapace distinctly narrowed posteriorly, slightly wider than long in Picturmegops ); leg setae not long and dense (legs densely covered with long setae in Lagonoburmops ). Conspecific spiders have some morphological differences at different developmental stages ( Foelix, 2011 ). It is difficult to judge whether an adult male and a juvenile are the same species, especially in fossils. Therefore, we have erected a new genus Scopomegops based on CNU-ARA-MA2020001. Besides Scopomegops , seven species belonging to five genera of Lagonomegopidae are known to have one or more apophyses on the male palpal tibia. In Albiburmops annulipes Wunderlich, 2017 , the carapace length is equal to its width, whereas the carapace is distinctly much longer than wide in Scopomegops . In Archaelagonops propinquus Wunderlich, 2015 and Archaelagonops scorsum Wunderlich, 2015 , the palpal tibia bears two apophyses, whereas there is only one in Scopomegops . In Cymbiolagonops cymbiocalcar Wunderlich, 2015 , the palpal tibia bears a divided apophysis, whereas the RTA is undivided in Scopomegops . In? Parviburmops bigibber Wunderlich, 2017 , the tibial apophysis is situated on the ventral surface, but is on the retrolateral surface in Scopomegops . In Paxillomegops longipes Wunderlich, 2015 and? Paxillomegops brevipes Wunderlich, 2015 , the palpal tibia bears numerous short peg bristles, which are lacking in Scopomegops .