Chaetotaxy is the arrangement of bristles (macrochaetae) on an

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

, or

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

based on their position and size. For example, it is important in Diptera, in which group it was formalised by Ernst August Girschner. The term chaetotaxy was later proposed by

Carl Robert Osten-Sacken Carl Robert Osten-Sacken or Carl-Robert Romanovich, Baron von der Osten-Sacken, Baron Osten Sacken (21 August 1828, – 20 May 1906) was a Russian diplomat and entomologist. He served as the Russian consul general in New York City during the A ...

. The chaetotaxy of a fly might include :- acrostichal, dorsocentral, humeral, mesopleural, sternopleural, notopleural, postalar, supraalar and scutellar bristles on the thorax; dorsal, posterodorsal, anterodorsal, ventral, posteroventral and anteroventral bristles on the legs and ocellar, orbital, postvertical, vibrissal, outer vertical and inner vertical bristles on the head. Chaetotaxy is also used in determining homology in certain morphological traits, as well as providing information about the

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spe ...

between taxa. For example, chaetotaxy has been used to clarify evolutionary relationships in

Collembola Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called E ...

, as well as identify new

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

References

*Capinera, J.L. (editor). 2008. ''Encyclopedia of Entomology'', 2nd Edition. Vols. 1-4. Springer, Dordrecht, The Netherlands. {{ISBN, 1-4020-6242-7. *McAlpine, J.F. 1981 Morphology and terminology - Adults. - In: McAlpine, J.P. et al. (eds.): ''Manual of Nearctic Diptera'', vol. 1; p. 9-63 - Ottawa: Research Branch, Agriculture Canada, Monograph 27. *Steyskal, G.C. (1976) The terminology of bristles on the upper back of the head in the higher Diptera. ''Journal of the Kansas Entomological Society'' 49 (2): 155-159.

External links

CSIRO Anatomy atlas
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TOL
Description of the family

Clusiidae Clusiidae or "druid flies" is a family of small (~ 3.5 mm), thin, yellow to black acalyptrate flies with a characteristic antenna (The second segment of the antennae has a triangular projection over the third segment when viewed from the o ...

including chaetotaxy.

References

External links

See also