''Allorapisma'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

lacewing The Hemerobiiformia are a suborder of insects in the order Neuroptera that include most of the lacewings, antlions and their allies. The phylogeny of the Neuroptera was explored in 2014 using mitochondrial DNA sequences. The results indicate t ...

in the moth lacewings family

Ithonidae Ithonidae, commonly called moth lacewings and giant lacewings, is a small family (biology), family of Pterygota, winged insects of the insect order (biology), order Neuroptera. The family contains a total of ten living genera, and over a dozen e ...

. The genus is solely known from two

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

fossils found in North America. At the time of description the genus was composed of a single species, ''Allorapisma chuorum''.

History and classification

''Allorapisma chuorum'' is known only from two fossils, the part side of the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

left fore-wing, specimen number SR 08-14-01, and the part side of a

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

right fore-wing, specimen number SRUI 08-04-01. Both the fossil are currently housed in the collections of the

Stonerose Interpretive Center The Stonerose Interpretive center & Eocene Fossil Site is a 501c(3), 501c(3) non-profit public museum and fossil dig located in Republic, Washington. The center was established in 1989 and houses fossils that have been featured in ''National Geo ...

Republic, Washington Republic is a city in Ferry County, Washington, United States. The population was 992 at the 2020 census. It is the county seat of Ferry County. It was the largest mining camp in the Republic Mining District, and home to the "Hot Air Line" rail ...

, US. The specimens are preserved as

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 ...

s in silty yellow to grayish

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

, which were recovered from outcrops of the Tom Thumb Tuff member of the

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington (state), Washington state. The formation is composed of volcanic rocks in the upper unit and volcanic plus lacu ...

. The formation is approximately

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

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

in age, being radiometrically dated as . ''Allorapisma'' was first studied by the paleoentomologists Vladimir N. Makarkin of the Far Eastern Branch of the Russian Academy of Sciences and S. Bruce Archibald from

Simon Fraser University Simon Fraser University (SFU) is a Public university, public research university in British Columbia, Canada. It maintains three campuses in Greater Vancouver, respectively located in Burnaby (main campus), Surrey, British Columbia, Surrey, and ...

Burnaby, British Columbia Burnaby is a city in the Lower Mainland region of British Columbia, Canada. Located in the centre of the Burrard Peninsula, it neighbours the City of Vancouver to the west, the District of North Vancouver across the confluence of the Burrard ...

. Their 2009

type description A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

of the new genus and species was published in the online journal ''

Zootaxa ''Zootaxa'' is a peer-reviewed scientific mega journal for animal taxonomists. It is published by Magnolia Press (Auckland, New Zealand). The journal was established by Zhi-Qiang Zhang in 2001 and new issues are published multiple times a week ...

''. The genus name ''Allorapisma'' was coined by the researchers as a combination of the moth lacewing type genus ''

Rapisma ''Rapisma'' is a genus of moth lacewings, Ithonidae. They were previously placed in family of their own, Rapismatidae. They are mostly brown or green and the body is broad and the head is short and retracted under the pronotum. Some species show ...

'' and the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word ''Allo'' meaning "other", which is in reference to the similarity of the new genus to ''Rapisma''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''chuorum'' is honor of the Chu family from

Kirkland, Washington Kirkland is a city in King County, Washington, United States. A suburb east of Seattle, its population was 92,175 in the 2020 U.S. census which made it the sixth largest city in King County and the twelfth largest city in the state of Washington. ...

who found the holotype and donated it to the Stonerose Interpretive Center. Overall the vein structure of ''Allorapisma'' is most similar to the genus '' Principiala'', known from

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

fossils found in both Brazil and England. Following the

Comstock–Needham system The Comstock–Needham system is a naming system for insect wing veins, devised by John Comstock and George Needham in 1898. It was an important step in showing the homology of all insect wings. This system was based on Needham's ''pretracheat ...

, the wings of both genera show the apical end of the Rs vein fused to the MA vein. Both have similar positioning and shaping of the MP vein and the CuA vein running parallel to the MP vein. As such, Makarkin and Archibald suggested the two be grouped in an informal suprageneric group called the ''Principiala'' group. This group is one of three possibly

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

groups in

, the others two being the ''Ithone'' group and the ''Rapisma'' group. Before the merging of the families Ithonidae and

Polystoechotidae Ithonidae, commonly called moth lacewings and giant lacewings, is a small family of winged insects of the insect order Neuroptera. The family contains a total of ten living genera, and over a dozen extinct genera described from fossils. The mod ...

in 2010, ''Allorapisma'' was the first Ithonidae fossil to be described from the

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

Description

The holotype and paratype are both composed of partially complete fore-wings, each of which is missing a sections of the lower wing edge. The preserved section of the holotype fore-wing is approximately long and wide. The paratype is slightly longer at and wide. The wings have a costal space that is wide, widening towards the wing base and narrowing towards the wing tip. The space between the R1 and Rs veins is notably larger than the subcostal space, while the costal space has several crossveins near the edge of the costal margin. The MA and MP veins are distinct in origins from each other, with the MA starting at the R vein, a character that is rare in Neuroptera.

References

{{Taxonbar, from=Q4733141 Ithonidae Fossil taxa described in 2009 Ypresian insects Eocene insects of North America Klondike Mountain Formation Monotypic prehistoric insect genera