100-Million-Year-Old Spider

100-Million-Year-Old Spider Attack Recorded in Amber

Looks like this 100-million-year old spider didn’t get to enjoy its final meal. Trapped in a piece of amber, the juvenile spider appears to be on the cusp of devouring a male wasp that was caught in its web. Such a grisly scene between spider and prey has never before been found in the fossil record. The amazing snapshot shows an event that occurred in the Early Cretaceous period, about 97 to 110 million years ago, in the Hukawng Valley of Myanmar, “almost certainly with dinosaurs wandering nearby,” as the press release about this discovery reports. The spider is a social orb-weaver spider, formally known as Geratonephila burmanica, and its victim is a wasp of the species Cascoscelio incassus. Both species are extinct today but the fossil suggests that insect behavior from the past is not too different from the present. Related wasp species are known to parasitize spider eggs, so there is some poetic justice in the spider’s attack. “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,” said entomologist George Poinar Jr. of Oregon State University in the release. This latest fossil doesn’t just capture the dramatic spider attack but also evidence of spider social life in the Early Cretaceous. Another spider, an adult male, is captured some distance away in the amber, co-habiting on the same web as the juvenile. Males of modern-day social orb-weavers are typically found living on female-constructed webs, where they assist in capturing insects and maintaining the web. Droplets on the fossil web also contain aerial plankton (pollen, spores and dust particles) from the time. A paper about the discovery appears Oct. 8 in the journal Historical Biology.