Credit: Photo by George Poinar Jr., Courtesy of Oregon State University

 

This one really was a fight for the ages. Researchers have discovered the only fossil known of a spider attack on prey caught in its web. The young male arachnid (top) was just about to pounce on a tiny parasitic wasp when the pair became smothered in tree resin in the Hukawng Valley of Myanmar 97 million to 110 million years ago. The result was a fossilized piece of amber that captured the event—complete with spider silk—in remarkable detail. The amber, described in the current issue of Historical Biology, also ensnared an adult male spider in the same web. Few arachnid species today are known to share a web, suggesting this is the oldest fossil evidence of social behavior in spiders.