Researchers have found what they say is the only fossil ever discovered of a spider attack on prey caught in its web – a 100 million-year-old snapshot of an engagement frozen in time.
The extraordinarily rare fossils are in a piece of amber that preserved this event in remarkable detail, an action that took place in the Hukawng Valley of Myanmar in the Early Cretaceous between 97-110 million years ago, almost certainly with dinosaurs wandering nearby.
Aside from showing the first and only fossil evidence of a spider attacking prey in its web, the piece of amber also contains the body of a male spider in the same web. This provides the oldest evidence of social behavior in spiders, which still exists in some species but is fairly rare. Most spiders have solitary, often cannibalistic lives, and males will not hesitate to attack immature species in the same web.
"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 University and world expert on insects trapped in amber. He 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 ancient invertebrates that researchers believe date back some 200 million years, but the oldest fossil evidence ever found of a spider web is only about 130 million years old. An actual attack such as this between a spider and its prey caught in the web has never before been documented as a fossil, the researchers said.
The tree resin that forms amber is renowned for its ability to flow over insects, small plants and other life forms, preserving them in near perfection before it later turns into a semi-precious stone. It often gives scientists a look into the biology of the distant past. This spider, which may have been waiting patiently for hours to capture some prey, was smothered in resin just a split second before its attack.
This type of wasp, Poinar said, belongs to a group that is known today to parasitize spider and insect eggs. In that context, the attack by the spider, an orb-weaver, might be considered payback.
Both the spider and the wasp belong to extinct genera and are described in the paper. 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.
Oregon State University: http://www.orst.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Claims that Ai Hin was faking pregnancy to get better treatment have been debunked by leading panda expert
The recent release of Susan Greenfields new book and the film Lucy, both of which are dependent on tired misconceptions or dubious theories about the brain, suggest one worrying conclusion: we are running out of myths about the brain. So here are some new ones, to keep things mysterious
These are the siphonophores, some 180 known species of gelatinous strings that can grow to 100 feet long, making them some of the longest critters on the planet. But instead of growing as a single body like virtually every other animal, siphonophores clone themselves thousands of times over into half a dozen different types of specialized cloned bodies, all strung together to work as a team---a very deadly team at that.
Researchers who study memory have had a thrilling couple of years. Some have erased memories in people with electroshock therapy, for example. Others have figured out, in mice, how to create false memories and even turn bad memories into good ones.
Hunting bats don't just listen out for male frogs' mating calls: they can also use echolocation to detect when the frogs inflate their throat sacs
A crèche of 30 dinosaur infants looked over by an older animal shows that even terrible lizards needed a night away from the kids
Families have identifiable collections of microbes that travel with them. It can take just 24 hours for the microbes to take over a new house
When rabbits were domesticated, around 100 regions of their genome changed to make them less fearful, but the variations are not fixed
Scientists never understood what became of the Paleo-Eskimos who once peopled the north. Now they know—and there's new reason to miss them
NOAA whittles down initial list of 66 species to be covered by Endangered Species Act