THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Monday, April 22, 1996 TAG: 9604220076
SECTION: LOCAL PAGE: B2 EDITION: FINAL
SOURCE: BY RICK WEISS, THE WASHINGTON POST
DATELINE: WASHINGTON LENGTH: Medium: 56 lines
A stone quarry straddling the border between Virginia and North Carolina has yielded some of the world's most impressive insect fossils from the Triassic period more than 200 million years ago, a time when dinosaurs were coming into their prime.
The shimmering silver imprints of flies, beetles and other insects - perfectly preserved in a finely grained, charcoal gray shale - show in astonishing detail the insects' mouthparts, head hairs and even the fine fringe found on some species' wings.
Scientists said the collection, which includes some of the oldest known examples of several major insect groups, reveals for the first time a bustling aquatic ecology that flourished during the Triassic period around the shores of a large lake near Danville, Va. It also indicates that insects had recovered quickly from the massive ``Permian extinction'' 20 million years earlier, which mysteriously wiped out about 95 percent of the Earth's animals and plants.
``This site may be one of the best in the world in terms of preservation,'' said Conrad C. Labandeira, a paleobiologist at the Smithsonian's National Museum of Natural History in Washington, who is familiar with the discovery. ``It also confirms that by the late Triassic we had insect communities that were structured very much along modern lines.''
Only two other sites - in Russia and Australia - contain good fossils from the Triassic period, which lasted from 245 million to 208 million years ago. As is generally the case with insects, however, those remains are mostly limited to wing parts, which are tough enough to survive the ravages of time.
The new find, described in Friday's issue of Nature, includes many insects whose soft body parts remain in excellent condition. Apparently, the insects settled to the bottom of the lake and were quickly buried in mud that sealed out all oxygen and bacteria, the major forces of degradation. Moreover, the mud was made of tiny particles about a micron in diameter, offering the equivalent of a fine-grained film.
``There is nothing like this anywhere else in North America,'' said David Grimaldi, an entomologist at the American Museum of Natural History in New York, who co-wrote the report with Nicholas Fraser of the Virginia Museum of Natural History in Martinsville and two colleagues. Grimaldi said the unprecedented degree of insect classification made possible by the fossils clearly shows that insects were well on their way to modern success relatively soon after the Permian extinctions.
The most common fossil insects recovered were waterbugs, swimming roach-like predatory insects about a half-inch long. Modern members of this group pierce their prey, inject tissue-dissolving poisons, and suck out their victim's soupy guts. The waterbug fossils are the oldest ever found. by CNB