Austrochilidae is a small

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

family with nine species in two genera. '' Austrochilus'' and '' Thaida'' are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the Andean forest of central and southern

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

and adjacent

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Taxonomy

, two

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

are placed in the family Austrochilidae: '' Austrochilus'' and '' Thaida'', found in

and

. The taxonomic placement of these genera has varied. In 1968, Lehtinen synonymized ''Austrochilus'' and ''Thaida'' under the latter name, placing the genus in a family he called "Thaididae". However, the family name "Thaididae" is preoccupied, being first used for a family of

gastropods Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. Ther ...

in 1887. A single family was accepted by Forster ''et al''. in 1987, under the name "Austrochilidae".

Molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies agree in placing the two genera as basal members of the

Araneomorphae The Araneomorphae (also called the Labidognatha or "true spiders") are an infraorder of spiders. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (taran ...

, although the precise details and the family placement are not yet agreed.

Phylogeny

One hypothesis for the phylogeny of the genera placed in the family is shown below (Austrochilidae genera in bold). The family shows a mixture of "primitive" and "advanced" features. The retention of four

book lung A book lung is a type of respiration organ used for atmospheric gas-exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open, ventral-abdominal, air-filled cavity (atrium) and co ...

s places the family at the base of the

, whereas some features of their silk production are regarded as derived.

Species

, the

World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...

accepts the following genera: *'' Austrochilus'' Gertsch & Zapfe, 1955 — Chile, Argentina *'' Thaida'' Karsch, 1880 — Chile, Argentina

References

* Grismado, C. J., L. Lopardo & N. I. Platnick (2003). A new species of ''Austrochilus'' from Chile (Araneae, Austrochilidae, Austrochilinae). J. Arachnol. 31: 148–150
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(''A. forsteri'') {{Taxonbar, from=Q5896 Spiders of Australia Spiders of South America Araneomorphae families

Taxonomy

Phylogeny

Species

See also

References