The order Neuroptera ‌Linnaeus, 1758 is one of the earliest lineages of holometabolous insects, with the earliest remains dating back from the Early Permian (Ponomarenko 2002) and is estimated to have been already present during the Carboniferous (Vasilikopoulos et al. 2020). During the Permian period, the group was not insignificant in number. For example, it makes up to 5.9% of all fossil insects collected at the Upper Permian Isady locality (European Russia), ranking fifth among insect orders (Aristov et al. 2013). However, the diversity of Permian Neuroptera at the family level was low. The 62 species and 25 genera described so far for the Permian all belong to the single family Permithonidae ‌Tillyard, 1922 (Prokop et al. 2015), except for Archeosmylus ‌pectinatus ‌Riek, 1953 from the Upper Permian of Australia,which belongs to the Archeosmylidae ‌Riek, 1953.

Diversification at the family level increased during the Triassic period, when some of the recent families of Neuroptera appeared, such as Psychopsidae ‌Handlirsch, 1906 and Berothidae ‌Handlirsch, 1906 (Khramov 2023; Lambkin 2014), as well as the first representatives of recent neuropteran super-families Osmyloidea Leach, 1830 and Ithonoidea Newman, 1853 (Khramov et al. 2024). The Triassic was also the time when some typical Mesozoic families appeared, such as the Osmylopsychopidae ‌Martynova, 1949 (Lambkin 2014), one of the most diverse and abundant groups of extinct Neuroptera. At the same time, families of Permian origin, the Permithonidae and Archeosmylidae, co-existed with these new lineages (Khramov 2024; Montagna et al. 2024) and subsequently went extinct by the Jurassic. In sum, the Triassic marked a transition from comparatively uniform Permian faunas to more diverse Mesozoic and Cenozoic assemblages.

To gain a more detailed picture of this transitional stage, it is crucial to broaden the geographical scope of the Triassic record of the order. So far, Triassic Neuroptera have only been recorded from two continents, Australia and Eurasia. The richest and most abundant (but still understudied) assemblage of Triassic Neuroptera comes from the Madygen locality (Kyrgyzstan, Central Asia; Khramov 2023, 2024). Two other important sources of Triassic Neuroptera are various localities in Queensland (Australia; Lambkin 1988, 1992, 2014, 2024; Riek 1955, 1956; Tillyard 1917, 1919, 1922, 1923) and the Ominé locality (Momonoki Formation; Khramov et al. 2024). Isolate findings of Triassic Neuroptera have been reported also from France, China and Switzerland (Ellenberger et al. 1952, Hong 1980, Montagna et al. 2024). In the present paper, we add to this list a new Triassic Neuroptera site in South Africa, namely the Molteno Formation. This unit is the lowest part of the Upper Triassic-Lower Jurassic Stormberg Group, which covers portions of the Eastern Cape Province of South Africa in the Karoo basin (Chima et al. 2018). The Molteno Formation, up to 600 m thick, extends over an area roughly 400 km north to south and 200 km west to east. Fossils from the Molteno Formation, primarily consisting of plants and insects, have been collected from 69 sites scattered across the region (Anderson et al. 1998). The Molteno Formation was deposited in braided river channels and consists of different types of sediments, including conglomerates, sandstones, siltstones, mudstones as well as coal seams (Anderson et al. 1998; Chima et al. 2018). It yielded more than 2000 fossil insects, which are most abundant in laminated shales deposited in the floodplain lakes (Anderson et al. 1998). Among them, only three belong to the Neuroptera, one of them being the focus of the current account.

The fossil specimen PRE/F/21985 newly described herein (Fig. 1) was collected from the lacustrine deposits at Aasvöelberg (Aas) 411 site, located in the north-central part of Eastern Cape Province, 50 km southwest of the town of Molteno (South Africa), and belonging to the Molteno Formation. It is estimated to be Carnian in age based on plant macrofossils (Anderson et al. 1998; Anderson & Anderson 2023). The fossiliferous horizon at Aas 411 is two-meter thick, consisting of highly baked yellowish-grey rhythmically bedded and thinly laminated shales (Labandeira et al. 2018; Scott et al. 2004). Fossil insects are diverse at Aas 411, numerically dominated by Coleoptera Linnaeus, 1758 and Blattodea Latreille, 1810 (Labandeira et al. 2018; Scott et al. 2004). The specimen is housed at the Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg (South Africa).

Photographs of this specimen were taken using a Canon EOS 5D Mark III equipped either with a 50 mm (general view; Fig. 1A) or a MP-E 65 mm (details; Fig. 1C) macro lens (all Canon, Tokyo, Japan). Obtained photographs were optimized using Adobe Photoshop CS6 (Adobe Systems, San Jose, CA, USA). Additionally, a draft drawing was prepared with the aid of a Zeiss SteREO Discovery V8 Stereomicroscope equipped with a pair of W-PL 10x/23 eye pieces, a Plan Apo S 1.0x FWD objective, and a drawing tube (Jena, Germany). A vector drawing (Fig. 1B) was produced using Adobe illustrator CS6 (Adobe Systems, San Jose, CA, USA) based on a working document composed of a scan of the draft drawing and multiple photographs as original data layers.

To conduct our comparative analysis, we also relied on four new photographs of the holotype of Petropsychops ‌superbus ‌Riek, 1956 [of both positive and negative imprints; housed at the Geosciences Collection, Queensland Museum, Brisbane (Australia); specimen number UQ C2135-6; Fig. 2A] made on request by G. Thompson (Queensland Museum) using a Canon 5DS equipped with a MP-E 65 mm macro lens. Each photograph was the outcome of the stacking of 11 source images (produced with the Zerene Stacker software) and further edited with Adobe Photoshop and Topaz AI Sharpening. The apical fragment of the specimen was re-adjusted digitally. A vector drawing was produced as specified above, based on a working document composed of the 4 new photographs and a scan of the drawing of the specimen by Lambkin (2014: fig. 9) as data layers.

Venation terminology and abbreviations follow Peng et al. (2016; and see reference therein for alternative homologies and terminology), as follows.

AA anterior analis;

CuA anterior cubitus;

CuP posterior cubitus;

M media;

R1 first branch of the radius;

Rs sector of the radius;

Rs1 first posterior branch of Rs;

Sc subcosta.

As already noted by Riek (1974) and further exemplified recently (Béthoux & Anderson 2021, 2023, Tierney et al. 2020), the insect fauna from the Molteno Formation (South Africa), of Carnian age (Anderson & Anderson 2023), stands in close relationship to those from Australian localities from Denmark Hill and Mount Crosby (Australia), of Norian age (Raven et al. 2015), but also from that from the Anisian Gayndah Formation (Lambkin 2024), although the latter is less well-sampled. Similarity between these assemblages is not unexpected, as they were located in southern Gondwana, at a similar latitudinal range, within the same floristic sub-province (Anderson & Anderson 1993, Kustatscher et al. 2018; among others). Moltenopsychops ‌magnus ‌n. gen., n. sp. the first Triassic and, to our knowledge, the first Mesozoic species of Neuroptera to be described from Africa, provides additional evidence of these close ties. Indeed, the closest known relative of the new taxon is the monotypic genus Petropsychops, known by incomplete wings from Denmark Hill and Mount Crosby (Lambkin 2014; and references therein).

We are grateful to two anonymous reviewers for their careful appraisal of an earlier version of this account, and to the editorial board of Geodiversitas for handling peer reviewing and publication process. Data on the new fossil species were collected during two visits to the Evolutionary Studies Institute (School of Geosciences, University of the Witwatersrand; Johannesburg, South Africa; 2014, 2015). We are grateful to M. Bamford and T. Scott-Turner for their help during these visits, which were supported by two grants from the ‘Action Transversale Muséum Émergences’ from the ‘Muséum national d’Histoire naturelle’ (O. Béthoux, 2014, 2015) and by a grant from the DFG (WA 1492/12-1; T. Wappler and O. Béthoux, 2014). This research was also supported by the Russian Science Foundation, project no. 21-14-00284 (for AVK). We are grateful to K. Spring, G. Thompson and M. O’Neill (all Queensland Museum, Brisbane, Australia) for facilitating the production of, producing, and allowing the reproduction of new photographs of the specimen UQ C2135. Finally, we are grateful to further members of the Anderson clan for their dedication towards collecting fossil insects from the Molteno Formation.