The first adult mantis lacewing from Baltic amber, with an evaluation of the post-Cretaceous loss of morphological diversity of raptorial appendages in Mantispidae

Abstract

Mantis lacewings (Neuroptera: Mantispidae) are prominent and charismatic predatory representatives of Insecta. Nevertheless, representatives of the group are surprisingly scarce in Paleogene deposits after a relative abundance of specimens known from Cretaceous. Here we present Mantispa? damzenogedanica sp. nov., representing the first adult of Mantispidae described from Baltic amber and the only Eocene adult mantispid hitherto preserved in amber. The new fossil species is also among the earliest representatives of Mantispinae, certainly the oldest adult of this group described from amber. Additionally, we discuss the changes through time in the ecological morphospace within Mantispidae based on the morphological diversity (≈disparity) of the raptorial legs. Possible explanations for the post-Cretaceous decline in the morphological diversity of mantis lacewings are posited.

The First Fossil Record of a Mantis Lacewing Pupa, and a Review of Pupae in Mantispidae and Their Evolutionary Significance

“…This is not surprising, as former studies have indicated that Mesozoic representatives of Mantispidae were in certain aspects more derived than modern ones (e.g. Lu et al 2020;Shi et al 2020a, b;Baranov et al 2022a).…”

“…For a quantitative comparison between adult stages and pupae, we used the data set from Baranov et al (2022a) and expanded it. We consider here all pupae known from groups that were traditionally considered as ingroups of Mantispidae (see below for details).…”

“…The fossil record of mantis lacewings is especially rich in the Mesozoic, including numerous fossils in sedimentary rocks and in different types of ambers (see recent summary in Baranov et al 2022a). Fossils in sedimentary rocks are restricted to adult specimens.…”

“…A more restricted number of mantis lacewings has been provided by Eocene ambers so far. Four possible larvae (Ohl 2011;Wunderlich 2012) and a single adult (Baranov et al 2022a;Fig. 6) have been reported.…”

“…We here review the knowledge on pupae of Mantispidae and report the first fossil pupal remains of this group. We also use quantitative as-pects of pupae and compare these to a recent quantitative study of adults (Baranov et al 2022a). Based on this comparison we can discuss some aspects on the pupa stage and its significance for understanding the evolutionary history of Mantispidae.…”