May 3, 2002. Copyright 2002. Graphic News. All rights reserved.

Fossil plant could be most important flowering plant ever found

LONDON, May 3, Graphic News: The worldÕs oldest known flower never bloomed, but it has opened scientific questions into whether all modern flowering plants share underwater origins.  The newly discovered remains of the most complete flowering plant show it lived at least 124.6 million years ago, and grew in the water that refreshed the dinosaurs, according to University of Florida paleobotanist David Dilcher.

The Lower Cretaceous fossil had no petals, but there is no question it was a flowering plant because of the presence of seeds enclosed in an immature fruit -- a trait separating flowering plants (known as angiosperms) from all other seed plants. The discovery is important because it provides clues about how these now-extinct ancestors evolved into todayÕs flowering plants, said Dilcher. 

ÒFlowering plants are the dominant vegetation in the world today,Ó he said. ÒTheyÕre the basic food crop and fibre source for the worldÕs population. ItÕs useful for us to understand the relationships among flowering plants, especially in this day of molecular genetic manipulations.Ó

ÒWhen you sit down in the morning and have a bowl of Wheaties or cornflakes, thatÕs a flowering plant,Ó he said. ÒWhen you eat a beef steak, thatÕs from an animal that ate flowering plants. So, when we study this fossil, weÕre looking at the ancestry of what sustains us in the world today.Ó 

The plant was about 20 inches (51cm) high with thin stems stretching up to the surface and its pollen and seed organs extending above the water, Dilcher said. The seeds probably dispersed in the water and floated up along the shore and germinated in shallow water, he said. 

ÒThe mysteries of the origin and radiation of the flowering plants remain among the greatest dilemmas facing paleontology and evolutionary biology,Ó said William Crepet, plant biologist at Cornell University. ÒThis fossil represents the first evidence of an angiosperm that is basal to all other angiosperms, yet that does not fit within any modern taxonomic group of angiosperms. This makes it one of, if not the most important fossil flowering plants ever reported.Ó

The researchers, writing in the journal Science, conclude that the fossil consists of a new genus, Archaefructus, with two species, A. liaoningensis and A. sinensis, and constitutes a sister group, or Òclade,Ó to all other angiosperms. The fossil was found in Liaoning Province in China by local farmers who gave it to one of the paperÕs coauthors. 

ÒIt was a great surprise to find leaves typical of a plant that lived underwater with characteristics unique to flowering plants at such an early age in their history,Ó Dilcher added. 
/ENDS

Source: Science