Metapelma archetypon
Encyclopedia
Metapelma archetypon is an extinct species
of parasitic wasp
in the Eupelmidae
genus Metapelma. The species is solely known from the Early Eocene Baltic amber
deposits in the Baltic Sea
region of Europe. Of the thirty seven described species in the genus Metapelma, M. archetypon is the only species known from the fossil record.
paleoentomology collections in New York City
, USA. M. archetypon was first studied by Gary A. P. Gibson with his 2009 type description being published in the journal ZooKeys
. 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.
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 termial 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 forewings 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.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of parasitic wasp
Parasitic wasp
The term parasitoid wasp refers to a large evolutionary grade of hymenopteran superfamilies, mainly in the Apocrita. They are primarily parasitoids of other animals, mostly other arthropods...
in the Eupelmidae
Eupelmidae
Eupelmidae is a family of parasitic wasps in the superfamily Chalcidoidea. The group is apparently polyphyletic, though the different subfamilies may each be monophyletic, and may be elevated to family status in the near future. As presently defined, there are over 905 described species in 45 genera...
genus Metapelma. The species is solely known from the Early Eocene Baltic amber
Baltic amber
The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite, with about 80% of the world's known amber found there. It dates from 44 million years ago...
deposits in the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
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 13 by in size. The block is currently residing in the American Museum of Natural HistoryAmerican Museum of Natural History
The American Museum of Natural History , located on the Upper West Side of Manhattan in New York City, United States, is one of the largest and most celebrated museums in the world...
paleoentomology collections in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
, USA. M. archetypon was first studied by Gary A. P. Gibson with his 2009 type description being published in the journal ZooKeys
ZooKeys
ZooKeys is a peer-reviewed open access academic journal for the field of zoology. It was established in 2008, and the editor-in-chief is Terry Erwin from the Smithsonian Institution...
. The specific epithet "archetypon" was designated by Gary Gibson from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
() 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 7.7 millimetre (0.303149606299213 in) in length when the ovipositorOvipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
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 termial 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 forewings 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.