Deinodryinus aptianus

Olmi, Massimo, Rasnitsyn, Alexander P. & Guglielmino, Adalgisa, 2010, Revision of rock fossils of Dryinidae and Embolemidae (Hymenoptera: Chrysidoidea), Zootaxa 2499, pp. 21-38 : 30-31

Deinodryinus ? aptianus Olmi, Rasnitsyn & Guglielmino , n. sp.

Material examined: female holotype, PIN no. 3559/4586 from 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 (Early Cretaceous) (100–115 mybp).

FEMALE ( Fig. 10 ): length 6.2 mm; length of main regions: head: 0.87 mm; antennae: 3.06 mm; mesosoma: 1.37 mm; prothorax: 0.87 mm; mesothorax + metathorax + propodeum: 1.37 mm; gaster: 3.12 mm. Antennae filiform; 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. Propleura normal (as in extant dryinids).

Fore femora 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, with distal part much longer than proximal part. Pterostigma very narrow, with the following length/breadth ratio: 35:7. Petiole very short. Ovipositor present. Legs only partly visible. Fore femora very large (length/breadth ratio: 39:18), as in extant chelate female of dryinids. Chelae present, hardly visible. Rest of fore legs, partly missing. Mid and hind legs partly missing. Length of mid coxae: 0.62 mm. Length of hind coxae: 0.81 mm. Tibial spurs not visible.

MALE: unknown.

Remarks: this fossil is only visible in the ventral view and, as such, is difficult to place in a specific 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 new species belonging to the extant genus Deinodryinus R. Perkins, 1907 (Anteoninae) , because of the shape of pterostigma and stigmal vein and for the presence in 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 because Lonchodryinus has the hypostomal bridge much shorter than in Deinodryinus and in the species above described, we placed it 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 the above described species, we placed it in Deinodryinus . Another unusual character of the new species above described is the shape of antennae: they are filiform, as in males of Dryinidae , whereas in females usually they are clavate.

Deinodryinus areolatus ( N. Ponomarenko, 1975) , from Baltic amber, is the only known fossil of Deinodryinus . The type of this species, easily visible from all sides ( Fig. 2 in Ponomarenko, 1975; fig. 71 in Olmi, 1984), is a female with clavate antennae and eyes larger than in D. aptianus .

The above fossils are the only species of Deinodryinus known in Palaearctic region, with the only exception of D. tussaci Olmi, 1991 , from Morocco. The genus Deinodryinus is mainly spread in tropical and subtropical regions, with a supposed centre of origin in South America. The presence of fossil species in Baltic amber and Mongolia marl should mean that in the past these areas were characterized by warm climate and the genus had much wider distribution.

Figures

FIGURE 2. Baissobius minutus n. sp. (length 1.7 mm).

FIGURE 10. Deinodryinus? aptianus n. sp. (length 6.2 mm)