Two new fossil genera and species of Cerocephalinae (Hymenoptera, Chalcidoidea, Pteromalidae), including the first record from the Eocene Author Blaeser, Marcel Author Krogmann, Lars Author Peters, Ralph S. text ZooKeys 2015 545 89 100 http://dx.doi.org/10.3897/zookeys.545.6470 journal article http://dx.doi.org/10.3897/zookeys.545.6470 1313-2970-545-89 61C2313F341741698E3559D134F884E0 61C2313F341741698E3559D134F884E0 Taxon classification Animalia Hymenoptera Pteromalidae Tenuicornus gen. n. Type species. Tenuicornus dominicus sp. n. Material. Female holotype, preserved in Lower Miocene Dominican amber (20-15 Ma). Holotype deposited in the amber collection of the Senckenberg Forschungsinstitut und Naturmuseum Frankfurt am Main, Germany, collection number SMF Be 2395. Diagnosis. Funicle of female 6-segmented and clavate with F1-F2 longer than wide and F3-F6 wider than long and distally broadening; scape elongate (1/3 of total antennal length) (Fig. 2D). Face deeply impressed with one distinct seta at each side of lateral margin of the impression anterior to mandibular articulation; seta long and thickened, slightly clavate in shape (Fig. 2C). Inner antennal process (iap) very thin and nail-like, located above level of toruli at upper margin of facial impression. Position of iap distinctly above ventral margin of eyes, on level with middle of eyes (Fig. 2C, D). Fore wing without a tuft of erect setae at parastigma. Wing disc bare, without setal bases. Marginal vein four times as long as stigmal vein (Fig. 2E). Prepectus large and triangular. Mesonotum almost completely polished (Fig. 2B). Exerted part of ovipositor long, approximately 1/4 of gaster length (Fig. 2A). Etymology . The first letters of the generic name Tenui- are derived from the Latin word "tenuis" , meaning "thin" or "sharp" . The last letters -cornus of the generic name are derived from the Latin word "cornus" , meaning "horn" . The generic name is male in gender and refers to the thin inner antennal process.