Cretoneuronema, LIU & CHEN & ZHUO, 2022

LIU, XING-YUE, CHEN, ZU-LUAN & ZHUO, DE, 2022, Cretoneuronema gen. nov. (Neuroptera: Hemerobiidae), a new brown lacewing genus from the mid-Cretaceous Kachin amber, Palaeoentomology 5 (3), pp. 226-232 : 227-228

Cretoneuronema gen. nov.

( Figs 1–3 )

Type species. Cretoneuronema jarzembowskii sp. nov.

Etymology. The generic epithet Cretoneuronema is a combination of Creta - (from “Cretaceous”) and Neuronema (a genus-group name of Hemerobiidae ), in reference to the Cretaceous occurrence of the new genus and its morphological similarity to Neuronema .

Diagnosis. Forewing broadly ovoid; ScP and RA distally fused; two subcostal crossveins; RP and MA separately diverging from R, and closely spaced with each other, nearly at same level with 1scp-r; three radial crossveins, basal one nearly at same level with 2scp-r; MA pectinate, with anteriorly directed branches; CuP deeply forked; two gradate series of crossveins (i. e., 3ir and 4ir); crossveins proximad of inner gradate series (including pre-3ir1) present; crossveins between branches of CuA continuous with outer gradate series. Hind wing: ScP and RA distally fused; sinuate stem of MA entering RP distinctly distad origin of RP1; CuP present; two short gradate series of crossveins present respectively between branches of RP and branches of RP, MA, MP, and CuA.

Remarks. Among the fossil genera of brown lacewings, the new genus appears to be closely related to Promegalomus from the Late Jurassic, Cretomerobius from the Early Cretaceous and Eocene, and Proneuronema from the Eocene by the characteristic forewing MA (= ORB1), which is pectinate with anteriorly directed branches, the deeply forked forewing CuP, and the presence of complete outer gradate series in the forewing. Moreover, the combination of these characters is also shared by several extant genera, which is named the Megalomus -like genus-group by Makarkin et al. (2016), including Drepanacra Tillyard, 1916 , Austromegalomus Esben-Petersen, 1935 , Conchopterella Handschin, 1955 , and Neuronema McLachlan, 1869 . However, the new genus clearly differs from all these extant genera by the distal fusion of ScP and RA in both fore- and hind wings, and the presence of only two forewing ORB (i. e., RP and MA) separated from R near wing base. By these two characters, Cretoneuronema gen. nov. can be also distinguished from Promegalomus , Proneuronema , and Cretomerobius , in which the distal parts of forewing ScP and RA appears to be not fused (present in Promegalomus , Proneuronema , and Cretomerobius wehri Makarkin, Archibald & Oswald, 1993a ), the separating point of forewing RP (ORB2) is nearly at middle of wing, distinctly apart from the separating point of MA (ORB1) (present in Promegalomus ), and the forewing ORB3 is developed (present in Proneuronema and Cretomerobius ). The new genus differs from other two extinct genera from the Cretaceous, i. e., Plesiorobius Makarkin, 1994 and Hemeroberotha Makarkin & Gröhn, 2020 by the presence of separate origins of forewing RP and MA from R (= presence of two ORBs), while the latter two genera have a single stem of RP+MA; and it differs from the Cretaceous genus Purbemerobius Jepson, Makarkin & Coram, 2012 by the distal fusion of hind wing ScP and RA, while in the latter genus these two veins are terminally separated in the hind wing.

Figures

FIGURE 1. Cretoneuronema jarzembowskii gen. et sp. nov., holotype BXAM BA-NEU-010. Photographs of habitus. A, Dorsal view. B, Ventral view. Scale bars = 1.0 mm.

FIGURE 2. Cretoneuronema jarzembowskii gen. et sp. nov., holotype BXAM BA-NEU-010. Photographs. A, Antero-distal parts of right fore- and hind wings, showing fusion between ScP and RA (indicated by arrows). B, Basal part of right hind wing. C, Basal fork of forewing MP, showing closely spaced crossveins (indicated by arrows). D, Right protibia. E, Left protibia. F, Left mesotibia. G, Left protarsus. ts, tibial spur. Scale bars = 1.0 mm (A, B); 0.5 mm (C–G).

FIGURE 3. Cretoneuronema jarzembowskii gen. et sp. nov., holotype BXAM BA-NEU-010, drawings of wing venation. A, Right forewing. B, Right hind wing. Scale bars = 1.0 mm.