“These are the fastest-known arachnids so far,” says the study’s lead author, Hannah Wood, curator of spiders at the Smithsonian’s National Museum of Natural History. And they are the only ones known to catch prey in a way similar to trap-jaw ants. As such, Wood is calling these spiders, from the family Mecysmaucheniidae, “trap-jaw spiders.

http://player.ooyala.com/iframe.js#pbid=MGQxZGQ1N2VlMDRjNGJmNmFmN2QwY2U2&ec=BsdG9tMjE6F0xo12_zmWk3jgLDGN6GaeThis Semysmauchenius spider can make a strike with its chelicerae in just 0.56 milliseconds. The spider was recorded at 3,000 frames per second (fps), but the video is playing at 20 fps, so in real life its movements would be 150 times as fast as seen here.
”Mecysmaucheniidae spiders are especially secretive creatures, tiny and difficult to spot on the forest floor in their native New Zealand and southern South America. Experts have described 25 species in the family, but another 11 await descriptions—and still more are likely waiting to be discovered.

Source: Tiny Spiders Are the Fastest Known on Earth | Science | Smithsonian

And, for my fellow arachnophiles, here’s an album of our insect preying friends: