The oldest wood known to this day was found in Anjou
An international team of researchers including Christine Strullu-Derrien, who wrote her thesis in the University of Angers, discovered two fossilized plants aged 397 and 407 millions years old. One was found near Angers. The fossils are certainly very old, but their composition is out of ordinary: the stems consist of wood! The scientists were previously convinced that wood appeared 10 millions years later.
At the beginning, the quarry of Chateaupanne
In 2006, Christine Strullu-Derrien collected specimens of a fossil plant in the quarry of Chateupanne (Chalonnes-sur-Loire, south-west of Angers) with the assistance of Hubert Lardeux, a geologist. Some bright spots captivate researchers’ attention: “It seemed evident that this plant differed from contemporary species”, the scientist said.
The cross-section of wood were examined under a microscope and revealed that stems -fossilized in the form of pyrite- were made of wood.
A better understanding of the evolution
The discovery shows that wood appeared during the Devonian (period between 416 and 359 millions years ago), before leaves and seeds. This research has provided useful clues about the emergence of plants and has modified the time-line of plant evolution.
Christine Strullu-Derrien and her colleagues are now working on phylogenesis (the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms) of the Angevin fossil. Now extinct, this plant – an ancestor of lignophytes- was 10 to 20 centimeters (7.87 inches) tall. It could be characterized as the first expression of wood even if its body was not exactly the same as today. The plant will be named soon by the team. At the moment, the researchers are describing it and trying to situate it in evolutionary history.
Read the article published August 12, 2011 in Science by the team.