Cheiracanthium
Guides
Cheiracanthiidae
Long-legged Sac Spiders
Cheiracanthiidae is a family of araneomorph spiders established by Wagner in 1887, with priority over the synonym Eutichuridae. The family contains approximately 15 genera and 385 species as of 2026, with Cheiracanthium being the largest and most species-rich genus. Members are commonly known as long-legged sac spiders. The family's phylogenetic placement has been historically contested, having been assigned to Clubionidae, Miturgidae, and Eutichuridae before recognition as a distinct family. Molecular analyses indicate Cheiracanthium is paraphyletic, with divergence estimated at 67 million years ago.