Researchers have discovered what they say is the only known fossil depicting an ancient spider attack on its prey. The fossil, preserved in a piece of amber tree resin, has been aged at between 97 and 110 million years old, “almost certainly with dinosaurs wandering nearby,” states a news release issued by Oregon State University.

Photo showing 100-million-year-old spider attack fossil is courtesy of Oregon State University

The spider attack occurred in the Hukawng Valley of Myanmar in the Early Cretaceous period. The fossil also contains the body of a male spider in the same web and provides what scientists say is the oldest evidence of social behavior among spiders.

The “extraordinary rare” find is all the more remarkable because of the fossil’s sharp detail.

“This juvenile spider was going to make a meal out of a tiny parasitic wasp, but never quite got to it,” said George Poinar Jr., a professor emeritus of zoology at Oregon State, and a leading expert on insects trapped in amber.

Poinar outlined the findings in a new publication in the journal Historical Biology.

“This was a male wasp that suddenly found itself trapped in a spider web,” Poinar said. “This was the wasp’s worst nightmare, and it never ended. The wasp was watching the spider just as it was about to be attacked, when tree resin flowed over and captured both of them.”

Spiders are believed to date back about 200 million years, but the oldest fossil evidence is 130 million years old.

The spider and wasp depicted in the newly discovered fossil are species that are now extinct.

Concludes the news release: “At least 15 unbroken strands of spider silk run through the amber piece, and on some of these the wasp was ensnared. Its large and probably terrified eyes now stare for eternity at its attacker, moving in for the kill.”