As of November 2021[update], two genera are placed in the family Austrochilidae: Austrochilus and Thaida, found in Chile and Argentina.[3] The taxonomic placement of these genera has varied. In 1968, Lehtinen synonymizedAustrochilus and Thaida under the latter name, placing the genus in a family he called "Thaididae".[4] However, the family name "Thaididae" is preoccupied, being first used for a family of gastropods in 1887.[3] A single family was accepted by Forster et al. in 1987, under the name "Austrochilidae".[2]Molecular phylogenetic studies agree in placing the two genera as basal members of the Araneomorphae, although the precise details and the family placement are not yet agreed.[5]
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 lungs places the family at the base of the Araneomorphae, whereas some features of their silk production are regarded as derived.[5]
^Lehtinen, P.T. (1967). "Classification of the cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha". Annales Zoologici Fennici. 4: 199–468.
^ abWheeler, Ward C.; Coddington, Jonathan A.; Crowley, Louise M.; Dimitrov, Dimitar; Goloboff, Pablo A.; Griswold, Charles E.; Hormiga, Gustavo; Prendini, Lorenzo; Ramírez, Martín J.; Sierwald, Petra; Almeida-Silva, Lina; Alvarez-Padilla, Fernando; Arnedo, Miquel A.; Benavides Silva, Ligia R.; Benjamin, Suresh P.; Bond, Jason E.; Grismado, Cristian J.; Hasan, Emile; Hedin, Marshal; Izquierdo, Matías A.; Labarque, Facundo M.; Ledford, Joel; Lopardo, Lara; Maddison, Wayne P.; Miller, Jeremy A.; Piacentini, Luis N.; Platnick, Norman I.; Polotow, Daniele; Silva-Dávila, Diana; Scharff, Nikolaj; Szűts, Tamás; Ubick, Darrell; Vink, Cor J.; Wood, Hannah M. & Zhang, Junxia (2016). "The spider tree of life: phylogeny of Araneae based on target-gene analyses from an extensive taxon sampling". Cladistics. 33 (6): 574–616. doi:10.1111/cla.12182. PMID34724759. S2CID35535038.
Grismado, C. J., L. Lopardo & N. I. Platnick (2003). A new species of Austrochilus from Chile (Araneae, Austrochilidae, Austrochilinae). J. Arachnol. 31: 148–150. PDF (A. forsteri)