The atypical tarantulas or purseweb spiders (family Atypidae) consist of only two genera. In the United States these are Sphodros and Atypus, and in Europe, Asia and Africa only Atypus.

Atypus piceus

Atypus lives in a silken tube parallel to the surface of the ground, while Sphodros usually props its tubes against a tree trunk. The females generally do not leave their silken tubes, but catch insects that crawl on the tube by biting the prey through the silk. Atypical tarantulas have huge chelicerae for their size and relatively long spinnerets (although not as long as those found in diplurids). The males are sometimes brightly colored and wander around looking for females in their tubes. The females are reddish-brown or dark-colored.

This North Carolina male (note the very large pedipalps) Sphodros rufipes specimen is making a threat display. (The chelicerae and fangs are very large also, the better to bite through silken tubes.) When approached with a Q-tip this individual exhibited a preference for biting first and then running.

External links

• Spiders of NW-Europe
• Platnick, N.I. 2003. World Spider Catalog
• Richman, D. B. 2003. Some Spiders - Photograph of Sphodros