''Deinodryinus areolatus'' is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of '' Deinodryinus'' in the

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. ...

family

Dryinidae Dryinidae is a cosmopolitan family of solitary wasps. Its name comes from the Greek ''drys'' for oak: Latreille named the type genus ''Dryinus'' because the first species was collected in an oak plant in Spain. The larvae are parasitoids of the ...

. The species is solely known from an

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

fossil found in the Baltic region.

History and classification

''Deinodryinus areolatus'' is known only from a single fossil, the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

, specimen number PIN No. 964/60, which is housed in the A.A. Borissiak

Paleontological Institute, Russian Academy of Sciences The Paleontological Institute, Russian Academy of Sciences (PIN; russian: Палеонтологический институт РАН) in Moscow is among the world's largest paleontological institutes. An affiliate of the Russian Academy of Scienc ...

, in

Moscow Moscow ( , US chiefly ; rus, links=no, Москва, r=Moskva, p=mɐskˈva, a=Москва.ogg) is the capital and largest city of Russia. The city stands on the Moskva River in Central Russia, with a population estimated at 13.0 millio ...

. The specimen is composed of a fully complete adult female wasp. The specimen is preserved as an

inclusion Inclusion or Include may refer to: Sociology * Social inclusion, aims to create an environment that supports equal opportunity for individuals and groups that form a society. ** Inclusion (disability rights), promotion of people with disabiliti ...

in a transparent chunk of

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In ...

. The amber dates to between forty and forty-five million years old, and, being

Baltic amber The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It was produced sometime during the Eocene epoch, but exactly when is controversial. It has been estimated that these forests created more than ...

dispersed in the sea, a more specific type location than the Baltic region is not possible to identify. ''Deinodryinus areolatus'' was first studied by the Russian paleoentomologist Nadezdha Ponomarenko in 1975, with a redescription by paleoentomologists Adalgisa Guglielmino and Massimo Olmi, both of the

University of Tuscia University of Tuscia ( it, Università degli Studi della Tuscia, UNITUS) is a university located in Viterbo, Italy. It was founded in 1979 and comprises 6 faculties. On 26 February 2019, the President of Republic Sergio Mattarella inaugurated th ...

. Ponomarenko's 1975 type description of the new genus and species was published in the Russian journal '' Paleontologicheskiy Zhurnal'', with the species placed by her into a new genus ''Electrodryinus''. ''Electrodryinus '' was subsequently synonymized with ''Deinodryinus'' in a 1984 paper by Massimo Olmi, resulting in the current binomial ''Deinodryinus areolatus''. ''D. areolatus'' was the first of three ''Deinodryinus'' species to be described from the fossil record. '' Deinodryinus velteni'' is also known from a fossil preserved in Baltic amber, while '' Deinodryinus? aptianus'' is known only from a Mongolian

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason f ...

in marl.

Description

The holotype specimen is a complete adult female preserved with areas of the face, vertex,

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum ( dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

, scutellum and

metanotum The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites ( exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) ...

obscured. Overall the female is in length, with antennae that are less than three times the length of the head and macropterous hyaline wings. The antennae are composed of ten segments, densely hairy, and distinctly clavate, (club shaped) in structure. The

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

s have four teeth on each side, which progress from large to small. The tooth size changes in relation to the placement front to back on the mandible. The

forewings Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwi ...

have three cells at the base that are formed by pigmented veins. The forewings have a pterostigma that is approximately four times as long as it is wide, and a stigmal vein that is not "S" shaped. The forelegs have a chelate structure, with the subapical tooth or other teeth.

References

{{Taxonbar, from=Q5252474 Dryinidae Eocene insects Fossil taxa described in 1975 Prehistoric insects of Europe Hymenoptera of Europe Baltic amber