SYSTEMATICS OF THE TRAPDOOR SPIDER GENUS 
A LI A TY PUS (ARANEAE: ANTRODIAETIDAE)* 
By Frederick A. Coyle 
Department of Biology, Western Carolina University, 
Cullowhee, North Carolina, 28723 
Introduction 
Aliatypus species are all rather stocky mygalomorph spiders (Figs. 
45-49) which construct a burrow with a trapdoor entrance from 
which they capture prey. In general morphology and behavior, 
Aliatypus bears striking resemblance to the distantly related trapdoor 
spider family Ctenizidae, but this similarity is clearly the result of 
convergent, or at least parallel, evolution; Aliatypus is an atypoid 
mygalomorph taxon most closely related to Antrodiaetus, Atypoides, 
and the Mecicobothriidae. Aliatypus species appear to be restricted 
to California and Arizona (Maps 1-4) where they live in ravine 
banks, road banks, or other slopes in habitats ranging from hot, dry 
sagebrush scrub communities to wet coast redwood forests and cool 
California red hr mountain forests. They are among the most 
abundant trapdoor spiders in California. 
Aliatypus has been badly neglected; only one species has been 
described (Banks, 1896; Smith, 1908) and little natural history 
information has been published (Smith, 1908; Gertsch, 1949; Coyle, 
1971). During the last seven years a concerted collecting effort, 
largely by Wendell Icenogle and myself, has increased the availability 
of adult specimens from a dozen to 330 and has thereby made pos- 
sible this revision. My chief goal in this study has been to define 
accurately the species limits by means of an analysis of variation. 
The methods employed are essentially those of my earlier studies 
(Coyle 1968, 1971) and are summarized in the Methods section of 
this paper. Discussions of variation patterns are included in order 
to improve our understanding of geographic variation in mygalo- 
morph spiders and guide future research on Aliatypus. The consid- 
erable amount of behavioral and ecological data which has been 
collected will be published separately in a paper on Aliatypus natural 
history. 
* Manuscript received by the editor January 1, 1975. 
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