''Metapelma archetypon'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

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 parasitic wasp in the Metapelmatidae genus '' Metapelma''. The species is solely known from the

Early Eocene In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ...

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 1 ...

deposits in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

region of Europe. Of the thirty seven described species in the genus ''Metapelma'', ''M. archetypon'' is the only species known from the fossil record.

History and classification

''Metapelma archetypon'' is known only from one fossil, the holotype, number "AMNH BaJWJ-407", which is a single female specimen preserved, along with a spider, in a nearly rectangular amber block in size. The block is currently residing in the

American Museum of Natural History The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...

paleoentomology The most recent understanding of the evolution of insects is based on studies of the following branches of science: molecular biology, insect morphology, paleontology, insect taxonomy, evolution, embryology, bioinformatics and scientific computing ...

collections in

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

, USA. ''M. archetypon'' was first studied by Gary A. P. Gibson with his 2009

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

being published in the journal ''

ZooKeys ''ZooKeys'' is a peer-reviewed open access scientific journal covering zoological taxonomy, phylogeny, and biogeography. It was established in 2008 and the editor-in-chief is Terry Erwin (Smithsonian Institution). It is published by Pensoft Publ ...

''. The specific epithet "''archetypon''" was designated by Gary Gibson from the Greek (') which translates as "original" or "model". This is in reference to the similarity of the head and hind leg structure similarity between the extinct and extant species.

Description

The holotype of ''Metapelma archetypon'' is in length when the

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

is excluded. Several areas of the female are obscured or missing, with the dorsal mesosomal and part of the gastral structures covered by a white substance. The terminal sections of both antenna and three of the legs are missing and both hind tarsi have the apical three segments detached but still present. Also missing is the terminal section of the ovipositor sheaths. The

forewing 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 hindwin ...

s are hyaline in coloration. While ''M. archetypon'' has a deeply divided upper and lower mesepimeron separating the acropleuron and metapleuron, a feature found only in ''Metapelma'', the shapes of the hind legs and head are closer to the general morphology of the subfamily Neanastatinae. The basal Neanastatinae groundplan is thought to have been modified in the modern genera in the subfamily. Although not confirmed shape of the ovipositor and relationship in the genus ''Metapelma'' suggests ''M. archetypon'' was parasitic on

wood-boring beetles The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood (i.e., are xylophagous). In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The t ...

References

{{Taxonbar, from=Q6823096 Eocene insects † Prehistoric insects of Europe Fossil taxa described in 2009 Baltic amber