Astreptolabis
| Astreptolabis Temporal range: Earliest Cenomanian
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| Astreptolabis ethirosomatia | |
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| Astreptolabis laevisholotype | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Dermaptera |
| Family: | Pygidicranidae |
| Subfamily: | †Astreptolabidinae |
| Genus: | †Astreptolabis Engel,2011 |
| Species | |
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Astreptolabisis anextinctgenusofearwigin theDermapterafamilyPygidicranidaeknown from a group ofCretaceousfossils found inMyanmar.The genus contains two described species,Astreptolabis ethirosomatiaandAstreptolabis laevisand is the sole member of the subfamilyAstreptolabidinae.[1]
History and classification[edit]
Astreptolabis ethirosomatiais known only from a single fossil, theholotype,specimen number AMNH Bu-FB20, which is housed in the Amber Fossil Collection of theAmerican Museum of Natural HistoryinNew York City.The specimen is composed of a fully complete adult female earwig which has been preserved as aninclusionin a transparent chunk ofBurmese amber.[1]The age of the amber deposits inKachin Stateof northernmost Burma are understood to be about 100 million years old, placing them in the earliest part of theCenomanianstage of the Cretaceous.[2]TheAstreptolabisethirosomatiaholotype was recovered from outcrops near the city ofMyitkyinainKachin Stateand was first studied by paleoentomologistMichael S. Engelof the Division of Entomology at theUniversity of KansasinLawrence, Kansas.[1]Engel's 2011type descriptionof the new species was published in the online journalZooKeys.[1]The genus nameAstreptolabiswas coined by Engel as a combination ofGreekwordsastreptos,which means "not curved" andlabis,which means "forceps". This is in reference to the distinct structuring of the type specimenscerci or "pincers".Thespecific epithetethirosomatiais from the Greek wordsetheira,meaning "hairy" andsomation,the diminutive of the Greek word for "body". The subfamily name Astreptolabidinae is derived from the genus name with the suffix -inaeadded.[1]In 2020 a second species.A. laeviswas described.[3]
Several other earwing species have been found inBurmese amber.One other speciesTytthodiplatys mecynocercuswas described by Engel in the same 2011 paper, whileBurmapygia resinatawas described by Engel andDavid Grimaldiin 2004, with a fourth speciesMyrrholabia electrinafirst described byTheodore Cockerellin 1920.[1]An additional fifth and sixth speciesZigrasolabis speciosaandToxolabis zigrasiwere described by Engel and Grimaldi in 2014 paper.[4]
Description[edit]
The holotype specimen ofAstreptolabis ethirosomatiais a complete adult female with an overallcolorationthat appears to be mat brown to dark brown. The female is approximately 3.5 millimetres (0.14 in) in length when the cerci are included. The body is overall densely covered insetaethat are not thickened enough to be chaetulose. The antennae have a stoutscapeand are at least fourteen flagellomeres long. As is typical with earwigs, theforewingshave been modified intotegma.The tegma cover the four first segments of the abdomen and the abdomen comprises eight visible segments, also typical for female earwigs. The hind wings are present, but due to positioning of the tegma, are mostly obscured. The slender cerci are tubular and straight, tapering along the length to sharp points at the ends.[1]A. laevisis known from a holotype male, it is distinguished fromA. ethirosomatiaby more sparsesetationon the head,pronotum,andtegmina,larger compound eyes and absence of ocular setae.[3]
References[edit]
- ^abcdefgEngel, M.S. (2011)."New earwigs in mid-Cretaceous amber from Myanmar (Dermaptera, Neodermaptera)".ZooKeys(130): 137–152.doi:10.3897/zookeys.130.1293.PMC3260755.PMID22259272.
- ^Poinar Jr, G.; Huber, J.T. (2011)."A new genus of fossil Mymaridae (Hymenoptera) from Cretaceous amber and key to Cretaceous mymarid genera".ZooKeys(130): 461–472.doi:10.3897/zookeys.130.1241.PMC3260775.PMID22259293.
- ^abMao, Y.; Engel, M. S.; Ren, D.; Gao, T. (2020)."A new species ofAstreptolabisin mid-Cretaceous amber from northern Myanmar, with the discovery of the first male of Astreptolabidinae (Dermaptera) ".ZooKeys(911): 101–112.doi:10.3897/zookeys.911.38845.ISSN1313-2970.PMC7031395.PMID32104140.
- ^Engel, MS; Grimaldi, D (2014). "New mid-Cretaceous earwigs in amber from Myanmar (Dermaptera)".Novitates Paleoentomologicae.6:1–16.