Deinodryinus? aptianus Olmi, Rasnitsyn & Guglielmino

Guglielmino, Adalgisa & Olmi, Massimo, 2011, Revision of fossil species of Deinodryinus, with description of a new species (Hymenoptera, Dryinidae), ZooKeys 130, pp. 495-504 : 497-498

Deinodryinus? aptianus Olmi, Rasnitsyn & Guglielmino Fig. 1

Deinodryinus? aptianus Olmi, Rasnitsyn & Guglielmino 2010: 30.

Material examined.

Type: Holotype, female, MONGOLIA: Central Mongolia, Bayanhongor Aimag, 5-8 km N Bon Tsagan Nuur Lake, outcrop 87, bed 8, impressed in marl of the Khurilt rock unit probably of Aptian age (Early Cretaceous) (100-115 mybp)(PIN, No. 3559/4586).

Diagnosis.

Female with antenna filiform and compound eye small (Fig. 1).

Redescription.

Female: macropterous; length 6.2 mm; length of main regions: head: 0.87 mm; antennae: 3.06 mm; mesosoma: 1.37 mm; prothorax: 0.87 mm; me sothorax + metathorax + propodeum: 1.37 mm; metasoma: 3.12 mm. Antenna filiform (Fig. 1); antennal segments in following proportions: 14:12:14:12:13:17:15:13:12:15; length/breadth ratio of antennal segments 8-10: 8th: 13:3; 9th: 12:3; 10th: 15:3. Head only visible from ventral side. Occiput very deeply excavated, with hipostomal bridge short (in ventral side, length of occiput: 0.62 mm; hipostomal bridge: 0.62 mm; oral fossa: 0.43 mm). Palpi not visible. Compound eye small (Fig. 1). Propleura normal (as in extant dryinids). Profemur very large, covering ventral side of mesothorax. Forewing hyaline, with three basal cells completely enclosed by pigmented veins. Marginal cell closed. Stigmal vein regularly curved, distal part much longer than proximal part. Pterostigma very narrow, with following length/breadth ratio: 35:7. Petiole very short. Ovipositor present. Legs only partly visible. Profemur very large (length/breadth ratio: 39:18), as in extant chelate female of dryinids. Chela present, hardly visible. Remainder of forelegs, partly missing. Mid- and hindlegs partly missing. Length of mesocoxa: 0.62 mm. Length of metacoxa: 0.81 mm. Tibial spurs not visible.

Male: unknown.

Hosts.

Unknown.

Remarks.

This fossil is only visible in ventral aspect and is difficult accordingly to place within a particular genus. In addition, the legs are partly missing and the chela is hardly visible. However, it is possible to identify tentatively this specimen as a species of the extant genus Deinodryinus given the shape of the pterostigma and stigmal vein and for the presence in the forewing of three basal cells completely enclosed by pigmented veins. Among Anteoninae , the above characters may also place this specimen in Lonchodryinus Kieffer, 1905, but Lonchodryinus has the hypostomal bridge much shorter than in Deinodryinus . Given that the fossil exhibits the condition in the latter genus the authors placed the species in Deinodryinus . Among Dryinidae , the above characters of the forewing may also place this specimen in Dryininae and Gonatopodinae but because the occiput is less excavated in Dryininae and Gonatopodinae than in Deinodryinus , and in Deinodryinus? aptianus, attribution to Deinodryinus is more justified. Another unusual character of Deinodryinus? aptianus is the shape of the antennae: they are filiform, as in males of Dryinidae , whereas in females usually they are clavate ( Olmi et al. 2010).