The ground spiders (family Gnaphosidae) include nearly 2000 species in over 100 genera worldwide. This makes the family the 7th largest known. New species are still being discovered.

Common genera include Gnaphosa, Drassodes, Micaria, Cesonia, Zelotes and many others. Generally, ground spiders are characterized by having barrel-shaped anterior spinnerets that are one spinneret diameter apart. The main exception to this rule is found in the ant-mimicking genus Micaria. Another characteristic is an indentation in the endites (paired mouthparts anterior and lateral to the labium, or lip). All ground spiders lack a prey-capture web and generally run prey down on the surface.

At present, no ground spiders are known to be seriously venomous to humans. Very few people even notice these nearly worldwide reddish, brown, gray, striped or black spiders.

External links

• Arachnology Home Pages: Araneae

• Platnick, N.I. 2003. World Spider Catalog