Thaumasia is a genus of nursery web spiders that was first described by Josef Anton Maximilian Perty in 1833.

Species: it contains seventeen species, found in South America, Costa Rica, Panama, Honduras, and Mexico:

• Thaumasia abrahami Mello-Leitão, 1948 – Honduras to Brazil
• Thaumasia acreana Silva & Carico, 2012 – Brazil
• Thaumasia annulipes F. O. Pickard-Cambridge, 1903 – Suriname, Peru, Brazil
• Thaumasia argenteonotata (Simon, 1898) – Mexico to Brazil
• Thaumasia caracarai Silva & Carico, 2012 – Mexico to Brazil
• Thaumasia caxiuana Silva & Carico, 2012 – Brazil
• Thaumasia diasi Silva & Carico, 2012 – Ecuador, Brazil
• Thaumasia heterogyna Chamberlin & Ivie, 1936 – Panama to Brazil
• Thaumasia hirsutochela Silva & Carico, 2012 – Costa Rica to Brazil
• Thaumasia lisei Silva & Carico, 2012 – Brazil
• Thaumasia onca Silva & Carico, 2012 – Colombia to Brazil
• Thaumasia oriximina Silva & Carico, 2012 – Brazil
• Thaumasia peruana Silva & Carico, 2012 – Peru
• Thaumasia scoparia (Simon, 1888) – Venezuela
• Thaumasia senilis Perty, 1833 (type) – Costa Rica to Paraguay
• Thaumasia velox Simon, 1898 – Panama to Argentina
• Thaumasia xingu Silva & Carico, 2012 – Colombia to Brazil