Magnocula Viertler, Klopfstein & Spasojevic 2023, gen. nov.
Creators: name: Viertler, Alexandra
name: Urfer, Karin
name: Schulz, Georg
name: Klopfstein, Seraina
name: Spasojevic, Tamara
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Magnocula

description: Genus Magnocula Viertler, Klopfstein & Spasojevic gen. nov. (feminine)
urn:lsid:zoobank.org:act: D2B1B906-279E-440E-B666- F5984022A986
Etymology: The name is a combination of the latin words “magna” and “ocula”, meaning “large-eyed”.
Type species: Magnocula sarcophaga gen. et sp. nov.
Systematic placement: The long and narrow T 1, with its sternite fused and without glymma resembles some Diacritinae. Also, the fossils’ strong notaulus and the small areolet are characteristics found in Diacritinae. However, the taxa in this subfamily do not possess a complete sternaulus, are at least double the size, and have their nervellus intercepted, which is not the case in our fossil. The fossil also resembles Adelphion Townes, 1969 in Pedunculinae, with a similarly looking clypeus, wing venation, and T 1. But the notaulus shape disagrees with this genus, as well as the dimension of the laterotergite 2 and 3, and the shape of the ovipositor tip.
The fossil does also resemble some Orthocentrinae, with its setae on the ovipositor sheaths about as long as the sheath width or slightly shorter. Specifically, the short carina anterior of the notauli, and the shapes of the hypopygium and the ovipositor are similar to Symplecis Förster, 1869. But despite the similarities, the fossils mandibles do not agree with Orthocentrinae. Unfortunately, the dense fringe on the apex of the hind tibia, a character that would further support the placement in Orthocentrinae, is not discernible.
The fossil resembles taxa in the extinct subfamily Townesitinae, which is only known from Baltic amber. The similarities include the extremely small body size, tapered mandible, narrow temples, seemingly elongate scapus, long sternaulus, fully areolated propodeum, and the slender legs. However, the strongly developed epomia, together with the wing venation does not fit Townesitinae, which normally possess a very short r-rs vein, and generally stout and short 1 M + 1 R 1 and 2 M cells.
A long sternaulus, which reaches back to the posterior end of mesopleuron, is not only found in Townesitinae, but also in two extant subfamilies, Cryptinae and Phygadeuontinae. The sternaulus, which ends posteriorly above the mid coxa and the two bullae in vein 2m-cu, means the fossil resembles Phygadeuontinae more than Cryptinae. The quadratic and slightly petiolate areolet is still quite rare in both Phygadeuontinae and Cryptinae, and the observed shape of the first tergite, with the spiracle around the middle, is also not common in this group and points to a potentially ancestral position. Ancestral Phygadeuontinae seem to exhibit more plesiomorphic character combinations, as was already observed in the extinct genus Madma Viertler, Klopfstein & Spasojevic, 2022 (Viertler et al., 2022b).
The fossil combines characteristics of many extant genera and tribes of Phygadeuontinae, which are in agreement with the phylogenetic placement. However, given the similarities to some Orthocentrinae and Pedunculinae, and lack of some subfamily-specific morphological characters due to taphonomic processes, we add a question mark behind the subfamily name.
Diagnosis: Within Phygadeuontinae, the fossil seems to combine characteristics from different extant groups. With the rather deep and strongly converging notauli (Character #57 and # 58), the elongate area superomedia (not coded) and the very long first sternite (Character #174), the fossil resembles some genera previously placed in Chiroticina. But species of Chiroticina have mostly elongated maxillary palps and a long malar space, which is not the case in our fossil.
Phygadeuontine genera previously placed in the tribe Hemitelina can be excluded since they have the spiracle behind the middle and have their laterotergites 2 and 3 not creased.
The slender T 1 with the spiracle around the middle (Character #164 and #171) fits some genera previously placed in Bathytrichina. Many share characteristics with the fossil, such as a rather wide head (not coded) and an elongate area superomedia (not coded). Those genera have their pedicel rather large compared to the scape, but we are uncertain in the interpretation of pedicel and scape in our fossil, which might be either normal in dimensions or enlarged. We can exclude Apophysius Cushman, 1922 due to the single bulla in 2m-cu; Bathythrix Förster, 1869 due to weakly converging notauli, that reach only the centre of the mesoscutum; Chrysocryptus Cameron, 1902 due to the teeth length and the clypeus with modifications; Retalia Seyrig, 1952 and Rhabdosis Townes, 1970 due to not having propodeal apophyses; and Surculus Townes, 1970 due to the absence of the basal section of the lateral longitudinal carina and no propodeal apophyses. In addition, the quadratic and slightly petiolate areolet (Character #129) is not found in any taxa of Bathytrichina, or any other extant tribe. We therefore suggest a new extinct genus, Magnocula gen. nov.
Magnocula gen. nov. differs from the only other described extinct Phygadeuontinae, genus Madma Viertler, Klopfstein, & Spasojevic 2022, by not having a bilobed posterior transverse carina on the mesosternum, no tooth on the apical margin of the fore tibia and by having a quadratic areolet. Magnocula gen. nov. shows less plesiomorphic characteristics than Madma, thus, in contrast to Madma, we suggest it is a crown than stem Phygadeuontinae. In conclusion, since this fossils characteristic combination is not found elsewhere and the fossil shows quite a special quadratic areolet shape for the subfamily, we suggest a new genus.
Description: The new genus Magnocula gen. nov. exhibits a combination the following: Bidentate mandibles and the malar space 0.7 × of the mandible base width, the clypeus slightly convex without modifications on the apical margin, the eyes are large with 0.8 ×head height in lateral view, the occipital carina complete and antenna with 15–17 segments. The notaulus is deep and strongly converging to the middle of the mesoscutum. The epomia is rather strong in Magnocula gen. nov. and ventrally on a slight elevation. Sternaulus present and ending above the mid coxa, the posterior transverse carina of the mesosternum absent in front of mid coxa but present otherwise. Juxtacoxal carina present, as well as the lateromedian, lateral longitudinal and both transverse carinae. The fore wing with quadratic areolet, which is slightly petiolate, 2m-cu bowed outwards with two bullae, and 1cu-a meets 1 M + 1Rs interstitial. 2Cu absent in the hind wing. S1 almost reaching the posterior part of T 1, T 1 slender and with the spiracle around the middle. T 2 with gastrocoelus. Laterotergites of T 2– T 5 creased. T 8 is elongate dorsally, not forming a horn or boss. The length of the ovipositor sheath is around 0.3 × the metasoma length.
description: Published as part of Viertler, Alexandra, Urfer, Karin, Schulz, Georg, Klopfstein, Seraina & Spasojevic, Tamara, 2023, Impact of increasing morphological information by micro-CT scanning on the phylogenetic placement of Darwin wasps (Hymenoptera, Ichneumonidae) in amber, pp. 1-27 in Swiss Journal of Palaeontology (30) (30) 142 (1) on pages 19-20, DOI: 10.1186/s13358-023-00294-2, http://zenodo.org/record/12002950