Lepidochlamidae Wang et al., 2022, 2023

Wichard, Wilfried, 2023, Fossil Trichoptera embedded in mid-Cretaceous Burmese amber, Contributions to Entomology 73 (2), pp. 167-179 : 167

Family † Lepidochlamidae Wang et al., 2022 stat. nov.

Type genus + species.

Lepidochlamus nodosa Wang et al., 2022.

Family diagnosis

(based on Wang et al. 2022). Ocelli absent; antenna longer than forewing, at least 71 flagellomeres preserved; maxillary palpus five-segmented, terminal palpomere V longest, not annulated, shorter than combined lengths of preceding four palpomeres. Male forewing with forks I, III, and V; all crossveins absent. Hind wing covered with a single layer of angustifoliate scales; wing venation unknown. Tibial spur formula 2/4/4.

Systematic position.

The monobasic family Lepidochlamidae Wang et al., 2022 is transferred to the Integripalpian infraorder Brevitentoria and to its superfamily Leptoceroidea : Lepidochlamus nodosa is characterized by the absence of ocelli and by the presence of the five-segmented maxillary palps with terminal segment not annulated, the antennae longer than forewings and the mid-tibia with preapical and apical pairs of Tibial spurs . The combination of these morphological features clearly points to the superfamily Leptoceroidea ( Ross 1967; Weaver 1983, 1984; Frania and Wiggins 1997; Morse 1997).

According to Wang et al. (2022), the " Lepidochlamidae , whose hindwings are covered with scales, are the sister group of all other caddisflies ( Eutrichoptera )." But as a member of the monobasic family Lepidochlamidae of the superfamily Leptoceroidea it cannot be the oldest representative of the order Trichoptera , forming a sister group relationship to all other Trichoptera , as suggested.

The establishment of the new taxa by Wang et al. (2022) is an overestimation of the scales on its hind wings. Scales on the hind wings of Brevitentorian species do not enforce the exceptional position of the " early caddisfly evolution " The scales on the hind wings are not a unique feature. Single-layered scales also cover other hindwings, e.g. Helicopsyche kariona Ross, 1975, Helicopsyche boularia Ross, 1975 (see Johanson 1998) and both wings together e.g. Helicopsyche megalochari Malicky, 1974 as well as forewings, e.g. Lepidostoma americanum Flint and Wiggins,1961, Oecetis pechana Mosely & Kimmins, 1953. In xiphocentronid genera Drepanocentron and Abaria scales are found on fore- and hindwings as well on hindwings only ( Schmid 1982). Scales on the wings (also called scale-like setae or scaloid setae) are well known in Trichoptera families and are probably derived from primitive setae.

In addition, the wing vein reduction in general and here the forewing venation reduction of Lepidochlamus nodosa is clearly phylogenetically derived. The plesiomorphic complete set of five apical forks is reduced by the loss of forks II and IV, which is common in some families of Brevitentoria as well as in its family Lepidochlamidae . Moreover, the nygmata in fork II and occasionally in the thyridial cell may be absent, and also the crossveins that would occlude the discoidal, medial, and thyridial cells, are not discernable most likely due to the embedding condition in amber. In my experience, the crossveins and nygmata are very difficult or impossible to recognize in amber. Only a comparison of several specimens of the same species allows a reliable statement about the presence or absence of the nygmata and the cross veins. The fossil Lepidochlamus nodosa is based on a single specimen, moderately preserved in mid-Cretaceous Burmese amber, kept as holotype no. CNU-TRI-MA-2015501, in Capital Normal University, Beijing, China.