Camelomecia

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Camelomecia
Temporal range: Earliest Cenomanian
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Camelomecia janovitzi AMNH-BUTJ003 right profile.jpg
Camelomecia janovitzi holotype AMNH-BUTJ003
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Genus: Camelomecia
Species:
C. janovitzi
Binomial name
Camelomecia janovitzi
Barden & Grimaldi, 2016

Camelomecia is an extinct genus of stem-group ants not placed into any Formicidae subfamily. Fossils of the single known species, Camelomecia janovitzi, are known from the Middle Cretaceous of Asia. The genus is one of several ants described from Middle Cretaceous ambers of Myanmar.

Contents

History and classification

Camelomecia is known from three total adult fossils, the holotype, 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 the American Museum of Natural History, in New York City. The described specimens are of queen and drone caste adults which have been preserved as inclusions in transparent chunks of Burmese amber. [1] The amber specimens were recovered from deposits in Kachin State, in Myanmar. Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the Aptian  Cenomanian boundary, in the earliest Cenomanian. [2] [3]

The fossils were first studied by paleoentomologists Philip Barden and David Grimaldi, both of the American Museum of Natural History. [1] Barden and Grimaldi's 2016 type description of the new genus and species was published in the journal Current Biology. [1] The genus name Camelomecia was 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. The specific epithet janovitzi is a patronym honoring Tyler Janovitz who donated the type specimen for study. [1] Camelomecia is one of several ant genera described from Burmese amber the others being Burmomyrma , Ceratomyrmex , Gerontoformica , Haidomyrmex , Myanmyrma , and Zigrasimecia . [1] [3] [4]

Phylogeny

A phylogeny of stem group ants in relation to wasps and crown group ants was produced by Barden and Grimaldi in 2016. The phylogeny placed Camelomecia as a stem group genus of Formicidae, with no mention of a specific subfamily, rather leaving the genus as incertae sedis. The genus was recovered as close to both Sphecomyrma and Zigrasimecia which are both members of the subfamily Sphecomyrmicinae. [1]

Sphecomyrma freyi Sphecomyrma freyi AMNH-NJ943B.jpg
Sphecomyrma freyi
C. janovitzi profile Camelomecia janovitzi AMNH-BUTJ003 head profile.jpg
C. janovitzi profile
Zigrasimecia ferox Zigrasimecia ferox JWJ-Bu17 profile view.jpg
Zigrasimecia ferox
Hymenoptera
Bradynobaenidae  +  Apoidea

Chyphotes mellipes

Chalybion californicum

Heterogyna species

Formicidae
Haidomyrmecines

Haidomyrmodes mammuthus

Haidomyrmex scimitarus

Haidoterminus cippus

Sphecomyrma freyi

Camelomecia janovitzi

Myanmyrma gracilis

Zigrasimecia ferox

Gerontoformica spiralis

Gerontoformica magnus

Gerontoformica gracilis

Gerontoformica pilosus

Brownimecia clavata

Crown Group ants

Descriptions

Camelomecia has 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 the clypeal surface and 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 modified labrum has 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. The metapleural gland has 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 the propodium has a collar like ring of hairs. The gaster is 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]

C. janovitzi mandibles, labrum, and denticles Camelomecia janovitzi AMNH-BUTJ003 Head.jpg
C. janovitzi mandibles, labrum, and denticles

Similar to the C. janovitzi gyne is the Camelomecia species 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 the C. janovitzi gyne, which has a rounded propodium with a flattened front face. Due to the differences the specimen was assigned to Camelomecia, but not placed into C. janovitzi or a new species. [1]

An 8.5 mm (0.33 in) winged male was described as a possible Camelomecia specimen 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 fourteen hamuli on 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 of Sphecomyrma or Gerontoformica species. Unlike the described Camelomecia females, 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]

Related Research Articles

<i>Sphecomyrma</i> Extinct genus of ants

Sphecomyrma is an extinct genus of ants which existed in the Cretaceous approximately 79 to 92 million years ago. The first specimens were collected in 1966, found embedded in amber which had been exposed in the cliffs of Cliffwood, New Jersey, by Edmund Frey and his wife. In 1967, zoologists E. O. Wilson, Frank Carpenter and William L. Brown, Jr. published a paper describing and naming Sphecomyrma freyi. They described an ant with a mosaic of features—a mix of characteristics from modern ants and aculeate wasps. It possessed a metapleural gland, a feature unique to ants. Furthermore, it was wingless and had a petiole which was ant-like in form. The mandibles were short and wasp-like with only two teeth, the gaster was constricted, and the middle and hind legs had double tibial spurs. The antennae were, in form, midway between the wasps and ants, having a short first segment but a long flexible funiculus. Two additional species, S. canadensis and S. mesaki, were described in 1985 and 2005, respectively.

<span class="mw-page-title-main">Sphecomyrminae</span> Extinct subfamily of ants

Sphecomyrminae is an extinct subfamily of ants in family Formicidae known from a series of Cretaceous fossils found in North America, Europe, and Asia. Sphecomyrminae contains eight genera, divided into two tribes Sphecomyrmini and Zigrasimeciini. The tribe Sphecomyrmini contains the six genera Armania, Cretomyrma, Gerontoformica, Orapia, Pseudarmania and Sphecomyrma; while Zigrasimeciini contains Boltonimecia and Zigrasimecia. A number of taxa have been removed from the subfamily and placed either in other subfamilies or are now treated as incertae sedis in Formicidae.

<i>Brownimecia</i> Cretaceous ant genus described from amber fossils

Brownimecia is an extinct genus of ants, the only genus in the tribe Brownimeciini and subfamily Brownimeciinae of the Formicidae. Fossils of the single identified species, Brownimecia clavata, are known from the Middle Cretaceous of North America. The genus is one of several ants described from Middle Cretaceous ambers of New Jersey. Brownimecia was initially placed in the subfamily Ponerinae, until it was transferred to its own subfamily in 2003; it can be distinguished from other ants due to its unusual sickle-like mandibles and other morphological features that makes this ant unique among the Formicidae. The ant is also small, measuring 3.43 millimetres (0.135 in), and a stinger is present in almost all of the specimens collected. The morphology of the mandibles suggest a high level of feeding specialization.

<i>Zigrasimecia</i> Extinct genus of ants

Zigrasimecia is an extinct genus of ants which existed in the Cretaceous period approximately 98 million years ago. The first specimens were collected from Burmese amber in Kachin State, 100 kilometres (62 mi) west of Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and David Grimaldi published a paper describing and naming Zigrasimecia tonsora. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus Zigrasimecia was originally incertae sedis within Formicidae until a second species, Zigrasimecia ferox, was described in 2014, leading to its placement in the subfamily Sphecomyrminae. Later, it was considered to belong to the distinct subfamily Zigrasimeciinae.

<i>Haidomyrmodes</i> Extinct genus of ants

Haidomyrmodes is an extinct genus of ant in the formicid subfamily Haidomyrmecinae, and is one of only nine genera placed in the subfamily Haidomyrmecinae. The genus contains a single described species, Haidomyrmodes mammuthus. Haidomyrmodes is known from several Middle Cretaceous fossils which have been found in Europe.

<i>Haidoterminus</i> Extinct genus of ants

Haidoterminus is an extinct genus of ant in the Formicidae subfamily Haidomyrmecinae, and is one of only nine genera placed in this subfamily. The genus contains a single described species Haidoterminus cippus and is known from one Late Cretaceous fossil which has been found in North America.

<i>Haidomyrmex</i> Extinct genus of ants

Haidomyrmex is an extinct genus of ants in the formicid subfamily Haidomyrmecinae, and is one of nine genera placed in the subfamily Haidomyrmecinae. The genus contains three described species Haidomyrmex cerberus, Haidomyrmex scimitarus, and Haidomyrmex zigrasi. All three are known from single Late Cretaceous fossils which have been found in Asia. H. cerberus is the type species and Haidomyrmex the type genus for the subfamily Haidomyrmecinae.

<i>Burmomyrma</i> Genus of ants

Burmomyrma is an extinct genus of aculeate hymenopteran, suggested to be an ant. The genus contains a single described species, Burmomyrma rossi. Burmomyrma is known from a single Middle Cretaceous fossil which was found in Asia.

<i>Archimyrmex</i> Extinct genus of ants

Archimyrmex is an extinct genus of ant in the formicid subfamily Myrmeciinae, described by palaeoentomologist Theodore Cockerell in 1923. The genus contains four described species, Archimyrmex rostratus, Archimyrmex piatnitzkyi, Archimyrmex smekali and Archimyrmex wedmannae. Archimyrmex is known from a group of Middle Eocene fossils which were found in North America, South America, and Europe. The genus was initially placed in the subfamily Ponerinae, but it was later placed in Myrmeciinae; it is now believed to be the ancestor of the extant primitive genus Myrmecia from Australia. Despite this, Archimyrmex is not a member to any tribe and is regarded as incertae sedis within Myrmeciinae. However, some authors believe Archimyrmex should be assigned as incertae sedis within Formicidae. These ants can be characterised by their large mandibles and body length, ranging from 13.2 to 30 mm. They also have long, thin legs and an elongated mesosoma (thorax) and petiole.

Zigrasolabis is an extinct genus of earwig in the family Labiduridae known from Cretaceous fossils found in Myanmar. The genus contains a single described species, Zigrasolabis speciosa.

Toxolabis is an extinct genus of earwig in the dermapteran family Anisolabididae known from a Cretaceous fossil found in Burma. The genus contains a single described species, Toxolabis zigrasi.

<i>Myanmyrma</i> Extinct genus of ants

Myanmyrma is an extinct genus of ants not placed into any Formicidae subfamily. Fossils of the single known species, Myanmyrma gracilis, are known from the Middle Cretaceous of Asia. The genus is one of several ants described from Middle Cretaceous ambers of Myanmar.

Cananeuretus is an extinct genus of ant in the Formicidae subfamily Aneuretinae, and is one of two Cretaceous genera of the subfamily. The genus contains a single described species Cananeuretus occidentalis and is known from one Late Cretaceous fossil which has been found in North America.

Burmaleon is an extinct genus of lacewing in the family Osmylidae known from fossils found in Asia. The genus contains a single species, Burmaleon magnificus.

<i>Gerontoformica</i> Extinct genus of ants

Gerontoformica is an extinct genus of stem-group ants. The genus contains thirteen described species known from Late Cretaceous fossils found in Asia and Europe. The species were described between 2004 and 2016, with a number of the species formerly being placed into the junior synonym genus Sphecomyrmodes.

<i>Paraneuretus</i> Genus of ants

Paraneuretus is an extinct genus of formicid in the ant subfamily Aneuretinae known from fossils found in Asia and Europe. The genus contains three middle to late Eocene age species, Paraneuretus dubovikoffi, Paraneuretus longicornis, and Paraneuretus tornquisti.

<i>Ceratomyrmex</i> Extinct genus of ants

Ceratomyrmex is an extinct genus of ant in the Formicidae subfamily Haidomyrmecinae. The genus contains a single described species Ceratomyrmex ellenbergeri and is known from several Late Cretaceous fossils which have been found in Asia.

<i>Linguamyrmex</i> Extinct genus of ants

Linguamyrmex is an extinct genus of ant in the formicid subfamily Haidomyrmecinae, and is one of only nine genera placed in the subfamily Haidomyrmecinae. The genus contains three described species, Linguamyrmex brevicornis, Linguamyrmex rhinocerus, and the type species Linguamyrmex vladi all known from Late Cretaceous fossils found in Asia.

<i>Boltonimecia</i> Extinct genus of ants

Boltonimecia is an extinct genus of ant in the formicid subfamily Zigrasimeciinae. The genus contains a single described species, Boltonimecia canadensis, and is known from a single Late Cretaceous fossil which was found in Canada. The type species was originally described as a species of the extinct genus Sphecomyrma under the combination Sphecomyrma canadensis.

<span class="mw-page-title-main">Zigrasimeciinae</span> Extinct subfamily of ants

Zigrasimeciinae is a subfamily of ants, known from the Cretaceous period, originally named as the tribe Zigrasimeciini within the subfamily Sphecomyrminae by Borysenko, 2017, it was elevated to full subfamily in 2020. It contains three described genera. They are sometimes known as iron-maiden ants in reference to their densely spiked mouthparts, reminiscent of an iron maiden torture device, that were likely used to trap prey. Boltonimecia canadensis was described from Campanian Canadian amber out of Alberta, Canada, while the species of Protozigrasimecia and Zigrasimecia are both exclusively known from Cenomanian Burmese amber found in Myanmar.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 Barden, P.; Grimaldi, D.A. (2016). "Adaptive radiation in socially advanced stem-group ants from the Cretaceous". Current Biology. 26 (4): 515–521. doi: 10.1016/j.cub.2015.12.060 . PMID   26877084.
  2. 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. doi:10.1016/j.cretres.2012.03.014.
  3. 1 2 Barden, 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. PMID   25232618. Archived (PDF) from the original on 2016-03-04. Retrieved 2016-03-27.
  4. Perrichot, V.; Wang, B.; Engel, M. S. (2016). "Extreme Morphogenesis and Ecological Specialization among Cretaceous Basal Ants". Current Biology. 26 (11): 1468–1472. doi: 10.1016/j.cub.2016.03.075 . PMID   27238278.