Pseudoundacypha yananensis, Huang, 2023

Huang, Di-Ying, 2023, Discovery of Thripida from the Middle Jurassic Yan’an Formation, Zootaxa 5396 (1), pp. 22-25 : 24

Pseudoundacypha yananensis sp. nov.

Holotype. NIGP203301 , an almost complete forewing, basal-upper section slightly broken.

Etymology. Yan’an, a City of Shaanxi Province, where the specimen was collected.

Diagnosis. As for genus.

Type locality and horizon. Fossil locality near the Peizhuang Village , Yan’an City, Shaanxi Province; Middle Jurassic Yan’an Formation .

Description. Forewing small-sized, 2.4 mm long, 0.9 mm wide, widest at circa 3/4 of wing length; wing width distinctly increase backwards; ScP present, elongate, nearly parallel wing margin; RA slightly curved apically, reaching 3/5 of wing length; common stem of RP straight, RP 1 almost straight, RP2 curved, a little longer than RP 1; M stem straight, M 1 almost straight, reaching wing apex, M 2 straight, distinct shorter than M 1; CuA slightly curved posteriorly; RP branched earlier than M branched; CuP nearly straight, rather elongate, reaching more than 1/3 of wing length; a short crossvein cua-cup present; A 1 nearly straight, A 2 small and near wing base.

Remarks. Pseudoundacypha gen. nov. can be assigned into the clade Lophioneurida by the position of cua-cup ( Nel et al., 2012). Pseudoundacypha gen. nov. generally resembles Undacypha Vishniakova, 1981 , but differs from the latter by presence of ScP and RA making an angle with R stem ( Vishniakova, 1981; Ansorge, 1996; Nel et al., 2014). The new genus is also similar to Jantardachus reductus Vishniakova, 1981 , but they can be also distinguished by the above differences, as well as a distinct longer stem of RP in Pseudoundacypha gen. nov. ( Vishniakova, 1981; Nel et al., 2014).

The presence of a long ScP is a common character for Panthysanoptera, but it also occurs in some species of Lophioneurida such as Lophiocypha permiana Tillyard, 1935 , Lophioneura ustulata Tillyard, 1921 , and Lophioneurodes sarbalensis Becker-Migdisova, 1953 . Among them, the new species resembles the Permian L. permiana . Pseudoundacypha yananensis differs from the latter by RP and M forked with larger angles and presence of a relatively straight CuA. Pseudoundacypha yananensis also differs from the Late Jurassic Karatavocypha oculata Vishniakova, 1981 by a longer ScP, RP, M forked with smaller angles, and a longer common stem of RP.

Abundant fossils of Thripida from the Middle-Late Jurassic Daohugou biota were assigned within the two genera Undacypha and Lophiosina ( Nel et al., 2014; Huang et al., 2018; Lian et al., 2021). These genera are clearly different from the new genus by absence of ScP. Another species, Mesopsocus divaricatus Hong, 1983 , was initially classified within Psocoptera. In the original description and line drawing, a weak ScP is evident. It distinguishes itself from the new species by RP and M forked with much smaller angles and a distinct longer CuA ( Hong, 1983).