Atypoides
plus AntrodiaetusLineage of the Mygalomorph Spiders (Araneae, Antrodiaetidae)"
WORK
BY JEREMY MILLER
Cladistic analysis of the Atypoidesplus AntrodiaetusLineage of the Mygalomorph Spiders (Araneae, Antrodiaetidae)
Jeremy A. Miller and Frederick A. Coyle. 1996. Journal of Arachnology,24 (3): 201-213.
ABSTRACT. Cladistic analyses of the antrodiaetid spider genera AtypoidesO.P. - Cambridge 1883 and AntrodiaetusAusserer 1871 yield a much more completely resolved phylogeny than that proposed by Coyle in 1971. Twenty-nine potentially informative characters were used in the analyses, which were performed using PAUP's a posterioriweighting options. Three independent analyses were performed, each with a different outgroup. These outgroups were 1) the antrodiaetid genus AliatypusSmith 1908, the putative sister group of Atypoidesplus Antrodiaetus, 2) Aliatypus gulosus Coyle 1974, the most primitive Aliatypusspecies, and 3) a hypothetical ancestral taxon based on character states found in Aliatypusand the Atypidae, the latter being the putative sister group of the antrodiaetids. These three analyses produced a total of eight most parsimonious trees which support the following principal conclusions: 1) Atypoides,as defined by Coyle, is paraphyletic (Atypoides riversi0. P. - Cambridge 1883 plus At. gertschiCoyle 1968 share with Antrodiaetusa common ancestor not shared with Ar. hadrosCoyle 1968). 2) Antrodiaetus roretzi(L. Koch 1878) is a relict species which shares a unique common ancestor with all other Antrodiaetusspecies. 3) Coyle's unicolorgroup of nine Antrodiaetusspecies is paraphyletic; six of these form a recently-derived clade, (Antrodiaetus occultusCoyle 1971 (An. yesoensis[Uyemura 1942], An. cerberusCoyle 1971, (An. montanus [Chamberlin & Ivie 1933], (An. pugnax[Chamberlin 1917], An. hageni[Chamberlin 1917]), and the other three species, An. pacificus(Simon 1884), An. robustus(Simon 1890), and An. unicolor(Hentz 1841), are derived from more ancestral stock. 4) Coyle's lincolnianusgroup of three Antrodiaetusspecies, An. lincolnianus(Worley 1928), An. stygiusCoyle 1971, and An. apachecusCoyle 1971, represents a valid clade. Our phylogeny suggests that two separate vicariance events led to the evolution of the two east Asian members of this otherwise North American assemblage. Vicariance events that are indicated by geological evidence and consistent with our phylogeny are postulated to account for the present distribution of North American species. New putative synapomorphies of Antrodiaetus,and of Antrodiaetusplus Atypoides,are proposed.