Description of two new species of the mid-Cretaceous genus † Tichostephanus Engel (Hymenoptera, Gasteruptiidae)

The genus † Tichostephanus comprises unique apocritan hymenopterans characterized by distinct fore wing venation, featuring a very large submarginal cell, and a “bottle brush”-like sensilla on the ovipositor sheath. Recently, the genus has been transferred from Stephanidae to Gasteruptiidae (Evanioidea). In this study, two new species, † Tichostephanus qinshubao sp. nov. and † Tichostephanus yuchijingde sp. nov., are described and illustrated based on specimens from mid-Cretaceous Burmese amber. The new species are distinguished from previously described taxa by the length-to-width ratio of the pterostigma; the degree of curvature of vein 1Cu; the shape of the first subdiscal cell; and the presence or absence of transverse striae on the middle part of the pronotum. A key to all five known species of the genus is provided.