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.