Anonychomyrma constricta
| Anonychomyrma constricta Temporal range: Lutetian | |
|---|---|
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| Anonychomyrma constricta worker | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Genus: | Anonychomyrma |
| Species: | †A. constricta |
| Binomial name | |
| Anonychomyrma constricta (Mayr, 1868) | |
| Synonyms | |
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Anonychomyrma constricta is an extinct species of ant in the subfamily Dolichoderinae known from several Middle Eocene fossils found in Europe.[1] A. constricta is one of three species in the ant genus Anonychomyrma to have been described from fossils found in Baltic amber.[2]
History and classification
When described Anonychomyrma constricta was known only from ten separate fossils, the four designated type specimens and a group of six additional fossils, which are fossilized as inclusions in transparent chunks of Baltic amber.[1] Baltic amber is approximately forty six million years old, having been deposited during Lutetian stage of the Middle Eocene. There is debate on what plant family the amber was produced by, with evidence supporting relatives of either an Agathis relative or a Pseudolarix relative.[3] All the type specimens were collected over 125 years ago, and when first described were part of the University of Königsberg amber collection. The fossils were first studied by Austrian entomologist Gustav Mayr who placed the species in the genus Hypoclinea, now considered a junior synonym of the living genus Dolichoderus. Mayr's 1868 type description of the new species was published in the journal Beiträge zur Naturkunde Preussens.[1] The species was moved from Hypoclinea to the small related genus Bothriomyrmex in 1873 by Dalla Torre.[1] William Morton Wheeler in his 1915 paper The ants of the Baltic amber again moved the species, suggesting it would be better placed in the genus Iridomyrmex.[1] Wheeler based the placement on the structuring of the labial and maxillary palpi. This placement was unchallenged until the genus was reviewed and redefined and split up in 1992 by Steven Shattuck. In the review, Iridomyrmex was split into a more restricted genus group while the other species which did not match the definition, including "Iridomyrmex" constricta were moved to other genera. Based on a number of characteristics, the species was moved to the genus Anonychomyrma as A. constricta.[4] In addition to Anonychomyrma constricta, two other Anonychomyrma species are known from fossils, A. geinitzi and A. samlandica[2] both from Baltic, Bitterfeld and Rovno ambers. A. constricta and A. geinitzi have also both been identified from Scandinavian amber.[5]
Description
Overall A. constricta can be distinguished from the congeneric A. geinitzi in several ways. A. geinitzi individuals are overall more gracile in form with a less constricted mesonotum and the mesosoma has a less convex appearance. A. constricta specimens have maxillary palps which are six jointed, labial palps which are four jointed, and an abundantly hairy body. The antennae have a scape which is just passes the back-edge of the head capsule and both female and ergatomorphic (male) workers. The ergatomorphs have larger and more rounded compound eyes then the workers do and the antennae are overall longer than seen in the workers. Both males and workers have a five segmented gaster and the males are distinguished by the slightly protruding stipites at the tip of segment five.[1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Wheeler, W. M. (1915). "The ants of the Baltic amber". Schriften der Physikalisch-Ökonomischen Gesellschaft zu Königsberg 55 (4): 56–59.
- ↑ 2.0 2.1 Heterick, B. E.; Shattuck, S. (2011). "Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae)". Zootaxa 2845: 169.
- ↑ Henderickx, H.; Tafforeau, P.; Soriano, C (2012). "Phase-contrast synchrotron microtomography reveals the morphology of a partially visible new Pseudogarypus in Baltic amber (Pseudoscorpiones: Pseudogarypidae)". Palaeontologia Electronica 15 (2;17A,11p): 1–11.
- ↑ Shattuck, S. O. (1992). "Review of the dolichoderine ant genus Iridomyrmex Mayr with descriptions of three new genera (Hymenoptera: Formicidae)". Journal of the Australian Entomological Society 31: 13–18. doi:10.1111/j.1440-6055.1992.tb00453.x.
- ↑ Dlussky, G. M.; Rasnitsyn, A. P. (2009). "Ants (Insecta: Vespida: Formicidae) in the Upper Eocene Amber of Central and Eastern Europe". Paleontological Journal 43 (9): 1024–1042. doi:10.1134/S0031030109090056.