Phoriostephanus Engel and Huang, 2016

Ge, Si-Xun, Jiang, Zhuo-Heng, Ren, Li-Li, van Achterberg, Cornelis & Tan, Jiang-Li, 2023, New insights into the phylogeny of Stephanidae (Hymenoptera: Apocrita), with a revision of the fossil species, Arthropod Systematics & amp; Phylogeny 81, pp. 819-844 : 819

Genus † Phoriostephanus Engel and Huang, 2016

Type species.

† Phoriostephanus exilis Engel and Huang, 2016.

Diagnosis.

Head globose, ocelli gathered closely on vertex. Front tibia with distinct dentition and not compressed medially. Pronotum elongated with neck differentiated. Forewing with vein 2Rs+M distinctly developed, about as long as vein Rs+M. Hind femur comparatively slender, edentulous. Hind tibia slender, without concavity medially.

Remarks.

In the original description by Engel and Huang (2016), the monotypic genus † Phoriostephanus was assigned to the subfamily Schlettereriinae , as the type species with a mediodorsal swelling on its hind coxa, as well as a non-petiolate hind tibia. However, according to the type specimen, it also showed many unique characteristics that separate it from all known Stephanidae (e.g., a globose head without tubercles on the vertex, an edentulous hind femur, and a venation with the discal cell I distinctly shorter than sub-discal cell I). Notably, Engel and Huang (2016) also thought that † P. exilis stands out disparately among Stephanoidea . It may represent a more basal lineage sister to Schlettereriinae or may even be given family rank and placed as sister to Stephanidae . Based on the results of our phylogenetic analysis, † Phoriostephanus is excluded from Schlettereriinae . Considering that the known specimen is male (lacking many important morphological information of females in phylogeny) and only contain one species in its lineage, we prudently treated Schlettereriinae as incertae sedis within the family.