N.B. fossils show origins of wood
Change allowed knee-high plants to colonize the planet
Scientists in New Brunswick have discovered the earliest evidence of how wood evolved on the land the province now occupies.
Randy Miller, the geology curator at the Museum of New Brunswick, said the province has some of the richest fossil deposits anywhere in the world.
The new evidence pushes the origins of wood back further than previously thought.
"This evidence shows that plants developed a woody structure about 395 to 400 million years ago. So it pushes our knowledge of that part of plant evolution back a little more," he said.
The fossils were discovered on the Campbellton coast. North Carolina paleontologist Patricia Gensel published the finding this week in the journal Science.
Miller said Gensel's work sheds light on life during the Devonian period of Earth's history. It was a bleak time before animals when the tallest plants were only knee high and clustered around rivers and marshes.
"If you were to be dropped in Campbellton you would see volcanoes; you'd look across the landscape and there would be no trees. You'd walk down to the river margin or the estuary margin and you'd be walking through brush," he said.
Wood turned plants into world-conquerors
The innovation of wood gave plants the strength and the structure to colonize inland.
Botanist Stephen Clayden said the chance adaptation of woody cells had important advantages for drawing more water into the plant.
"It didn't have that kind of mechanical, or conducting, plumbing system to get water very far above the soil," he said of plant life at the time. "The limitations were really like those of say a sponge."
The findings show the wood cells evolved first into conifers and later the broadleaf forests that make so much of life on the planet today possible.
"Wood formation and the origin of wood formation is one of the most significant features in the history of the Earth," Clayden said.
Gensel has promised to return the fossils to the Museum of New Brunswick. The first wood fossils will be added to a collection of many more dead-end plants and species of the period dating back nearly half a billion years.