|
|
Germs Found Trapped in Amber Lived With First Dinosaurs |
|
Brian Handwerk for National Geographic News |
| December 13, 2006 |
|
Scientists have discovered a "microworld" of 220-million-year-old life trapped in tiny drops of ancient amber. The fossilized plant resin preserved bacteria, fungi, algae, and microscopic animals known as protozoans some 220 million years agothe era when the very first dinosaurs began to appear. Surprisingly, these microscopic organisms look quite familiar to today's scientists. Alexander Schmidt and colleagues from the Humboldt University of Berlin, Germany, report that the microbes have undergone few or no physical changes since the Triassic periodfrom 245 million to 208 million years ago. (See an interactive feature on sea monsters of the Triassic.) During Earth's many geological epochs and climatic shifts, countless species have appeared only to vanish or evolve. Yet these microbes appear to be related to present-day organisms. The find was described in this week's edition of the journal Nature. Extinction Survivors Most fossils of microorganisms have been found in marine sediments, not terrestrial environments. And such marine fossils typically reveal patterns of great change over Earth's many epochs, unlike the new Triassic amber find. "Many marine microorganisms serve as so-called index fossils [for the dating of rock sediments] because they are so characteristic for a single period of time," Schmidt said. Terrestrial regions changed as much as marine environments did during these shifts, he added, but not all of these changes registered at a microscopic scale. "Although there were big changes in the composition of forests from the Triassic to recent [times] their microhabitats probably changed little, even during extinction events," Schmidt explained. Many ancient organisms have been found in amber, but samples older than about 135 million years are quite rare. The amber was found near Cortina d'Ampezzo, a village in the Dolomites mountain range in northern Italy. During the Triassic, the region was covered by humid forests on the coast of an ancient sea. Free Email News Updates Best Online Newsletter, 2006 Codie Awards Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample). |
|   |
| © 1996-2008 National Geographic Society. All rights reserved. |