Tichostephanus Engel, 2019

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

Genera Incertae sedis Genus † Tichostephanus Engel, 2019

Type species.

† Tichostephanus hui Engel, 2019

Diagnosis.

Male, antenna relatively short with 12 robust flagellomeres. Head globose with about seven distinct coronal teeth on upper frons and vertex around ocelli; veins of forewing strongly reduced; pterostigma subparallel-sided, distinct elongate and acute apically; vein 1Rs/1M straight, few veins indistinguishable; vein Rs+M absent, vein 2Rs+M and 1m-cu continuous, forming straight elongated vein between anterior apex of subdiscal cell to origin of 2-Rs, thus forming massive submarginal cell owing to merging of submarginal and discal cells; apical abscissa of vein M absent; vein 2Cub absent, vein A elongated beyond 1cu-a and almost reach 2Cua; Hind wing with cu-a absent. Hind femur slender, edentulous. Hind tibia with its basal part petiolate while apical half distinctly flattened, without depression at inner side.

Remarks.

In our phylogenetic analysis, the monotypic genus † Tichostephanus showed a unique lineage that was sister to all other Stephanidae species. † Tichostephanus has many peculiar characteristics, like a short and robust antenna, absence of vein Rs+M, massive submarginal cell, edentulous hind femur, and strongly extended metasomal apex, which is not found in all other Stephaninae or even Stephanidae species. Combined with the phylogenetic analysis results, † Tichostephanus is excluded from Stephaninae . 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 † Tichostephanus as incertae sedis within the family.