Curious discovery: An assemblage of modern diatoms through a microscope. These specimens were living between crystals of annual sea ice in McMurdo Sound, Antarctica.
Credit: Gordon T. Taylor, Stony Brook University
PARIS: Though they are baffled as to how it got there, scientists have discovered a menagerie of perfectly intact marine micro-organisms trapped in tree resin at least 100 million years old.
The unexpected find in the Charente region of southwestern France pushes back by at least 20 million years the period when a type of single-cell algae known as diatoms are known to have appeared on Earth.
Prehistoric mystery
But just how did sea creatures wind up trapped in a glob of resinated amber that oozed out of trees?
The most likely scenario, concludes a study in the U.S. journal the Proceedings of the National Academy of Sciences, is that the forest producing the amber was very near the coast.
The tiny organisms, largely made up of prehistoric plankton, were either carried inland by strong winds or flood waters during a storm, the authors write.
"This discovery will deepen our understanding of these lost marine species as well as providing precious data about the coastal environment of western France during the Cretaceous Period," which spanned from 145 to 65 million years ago, the researchers said.
Molecular clock
It also challenges certain theories about the evolution of these organisms, and vindicates the research of molecular geneticists, said co-author Jean-Paul Saint Martin, a scientist at the National History Museum in Paris, France.
Using "molecular clocks," biochemists move backward in time to figure out at what point in the evolutionary process certain plant and animal species split off into different branches.
"We had no record of these micro-organisms over a period of 20 million years. These fossils have filled that void in the most extraordinary manner," said Saint Martin.
