Camelomecia
| Camelomecia Temporal range:
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|---|---|
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| Camelomecia janovitziholotype AMNH-BUTJ003 | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Genus: | †Camelomecia |
| Species: | †C. janovitzi
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| Binomial name | |
| †Camelomecia janovitzi Barden & Grimaldi, 2016
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Camelomeciais anextinctgenusofstem-groupantsnot placed into any Formicidae subfamily and probably not into Formicidae itself. Fossils of the single known species,Camelomecia janovitzi,are known from theMiddle CretaceousofAsia.The genus is one of several ants described from Middle Cretaceous ambers of Myanmar.
History and naming[edit]
Camelomeciais known from three total adult fossils, theholotype,specimen number "AMNH Bu-TJ003", and two additional fragmentary adults not designated as paratypes. At the time of the genus description, the three specimens were residing in theAmerican Museum of Natural History,inNew York City.The described specimens are ofqueen and drone casteadults which have been preserved asinclusionsin transparent chunks ofBurmese amber.[1]Theamberspecimens were recovered from deposits inKachin State,in Myanmar. Burmese amber has beenradiometrically datedusingU-Pbisotopes, yielding an age of approximately 98.79 ± 0.62 million years old, close to theAptian–Cenomanianboundary, in the earliest Cenomanian.[2][3]
The fossils were first studied by paleoentomologists Philip Barden andDavid Grimaldi,both of the American Museum of Natural History.[1]Barden and Grimaldi's 2016type descriptionof the new genus and species was published in the journalCurrent Biology.[1]The genus nameCamelomeciawas coined as a combination of the suffix "mecia" which is commonly used in ant genus names, and camel, in reference to the head when viewed from the side. Thespecific epithetjanovitziis a patronym honoring Tyler Janovitz who donated the type specimen for study.[1]Camelomeciais one of several ant genera described from Burmese amber the others beingBurmomyrma,Ceratomyrmex,Gerontoformica,Haidomyrmex,Myanmyrma,andZigrasimecia.[1][3][4]
Phylogeny[edit]
A phylogeny of stem group ants in relation to wasps and crown group ants was produced by Barden and Grimaldi in 2016. The phylogeny placedCamelomeciaas a stem group genus of Formicidae, with no mention of a specific subfamily, rather leaving the genus asincertae sedis.The genus was recovered as close to bothSphecomyrmaandZigrasimeciawhich are both members of the subfamily Sphecomyrmicinae.[1]
| Hymenoptera | |
In 2020,Camelomeciaand two species of the mid-Cretaceous genusCamelospheciawere placed in a clade that lies ouside of the Formicidae and forms the larger groupFormicoideawith it.[5]
Descriptions[edit]
Camelomeciahas an elongated head which flares out from the base area of the compound eyes and antennae sockets to the rear of the head capsule, which is gently rounded at the tip.[1]Occeli placed located on a ridge of raised cuticle, between the elliptical shaped compound eyes. The twelve segmented antennae are approximately 3.79 millimetres (0.149 in) long, and have a notably short scape. Of the segments, antennomeres four through eleven have small bases and widen unequally to the tops. The upper edges of the antennomeres have a point on the upper inner sides, giving the antennae a slightly serrate appearance. The mandibles have a distinct cup-like appearance, with the inner side of each cup towards theclypeal surfaceand a single tooth is present on the lower apex.[1]The front of the inner margins on the mandibles each have a row of thick setae while rows of denticles run along the dorsoventral edge. The modifiedlabrumhas a rounded, tongue like look extending between the mandibles. On each of the side edges of the labrum are a row of forward facing setae, while the front edge has many dense setae. The maxillary palps are composed of five segments and the labial palps are composed of three segments. Themetapleural glandhas a small slit like opening that has between three and four small setae on lower edge. The wings of the holotype are damaged and little is visible of the vein structure. The front edge of thepropodiumhas a collar like ring of hairs. Thegasteris attached to the petiole with a broad connection on the second metasomal segment, while the petiole is generally stalk shaped. A sting is present and partly extended from the gaster tip.[1]
Similar to theC. janovitzigyne is theCamelomeciaspecies gyne described, but the mandibles are slightly more elongated then the holotype gyne. Additionally the labrum has fewer setae on the lateral and frontal edges, and the side edges are darkened and clypeus has a rear margin that spans the full width of the head with the face being flattened dorsally. The propodium has a flat face on the back side and small spines, in contrast to theC. janovitzigyne, which has a rounded propodium with a flattened front face. Due to the differences the specimen was assigned toCamelomecia,but not placed intoC. janovitzior a new species.[1]
An 8.5 mm (0.33 in) winged male was described as a possibleCamelomeciaspecimen based on the similarities in wing veination and mandible structures. The wings are shortened, the forewings being about 4.96 mm (0.195 in) and the hindwings 3.96 mm (0.156 in). There are a total of fourteenhamulion the hindwings, all but one located towards the wing tip, with the last just to the base side of the Rs vein. The forewings have a very large parallelogram shaped DC cell and a DC2 cell, which is not seen in wings ofSphecomyrmaorGerontoformicaspecies. Unlike the describedCamelomeciafemales, the male has only eleven antennae segments, and the clypeus lacks denticles, rather a brush of fine setae is present. The gaster has preserved and distinct conical male genitalia.[1]
References[edit]
- ^abcdefghijkBarden, P.; Grimaldi, D.A. (2016)."Adaptive radiation in socially advanced stem-group ants from the Cretaceous".Current Biology.26(4): 515–521.Bibcode:2016CBio...26..515B.doi:10.1016/j.cub.2015.12.060.PMID26877084.
- ^Shi, G.; Grimaldi, D.A.; Harlow, G.E.; Wang, Ji.; Wang, Ju.; Yang, M.; Lei, W.; Li, Q.; Li, X. (2012). "Age constraint on Burmese amber based on U-Pb dating of zircons".Cretaceous Research.37:155–163.Bibcode:2012CrRes..37..155S.doi:10.1016/j.cretres.2012.03.014.
- ^abBarden, P.; Grimaldi, D. (2013)."A New Genus of Highly Specialized Ants in Cretaceous Burmese Amber (Hymenoptera: Formicidae)"(PDF).Zootaxa.3681(4): 405–412.doi:10.11646/zootaxa.3681.4.5.PMID25232618.Archived(PDF)from the original on 2016-03-04.Retrieved2016-03-27.
- ^Perrichot, V.; Wang, B.; Engel, M. S. (2016)."Extreme Morphogenesis and Ecological Specialization among Cretaceous Basal Ants".Current Biology.26(11): 1468–1472.Bibcode:2016CBio...26.1468P.doi:10.1016/j.cub.2016.03.075.PMID27238278.
- ^Brendon E. Boudinot; Vincent Perrichot; Júlio C. M. Chaul (December 2020)."†Camelosphecia gen. nov., lost ant-wasp intermediates from the mid-Cretaceous (Hymenoptera, Formicoidea)".ZooKeys(1005): 21-55.doi:10.3897/zookeys.1005.57629.