COLLEGE PARK, Md A fossil leaf fragment collected decades ago on a Virginia canal bank has been identified as one of North America's oldest flowering plants, a 115- to 125-million-year-old species new to science. The fossil find, an ancient relative of today's bleeding hearts, poses a new question in the study of plant evolution: did Earth's dominant group of flowering plants evolve along with its distinctive pollen? Or did pollen come later?
The find also unearths a forgotten chapter in Civil War history reminiscent of the film "Twelve Years a Slave." In 1864 Union Army troops forced a group of freed slaves into involuntary labor, digging a canal along the James River at Dutch Gap, Virginia. The captive freedmen's shovels exposed the oldest flowering plant fossil beds in North America, where the new plant species was ultimately found.
University of Maryland doctoral student Nathan Jud, a paleobotanist an expert in plant fossils and their environments identified the species and its significance. Jud named it Potomacapnos apeleutheron - Potomacapnos for the Potomac River region where it was found, and apeleutheron, the Greek word for freedmen. A paper describing the new species was published in the December 2013 issue of the American Journal of Botany.
Jud is studying the change that began 140 million years ago in the Early Cretaceous period, when plant communities of ferns gave way to a world dominated by flowering plants. In December 2011 he was at the Smithsonian Institution, where he is a pre-doctoral fellow, looking through clay-encrusted fossil ferns from Dutch Gap. Jud spotted one tiny leaf tip that seemed different.
A technician scraped away clay to reveal compound leaves, which placed the specimen in the flowering plant group known as eudicots. Today most flowering plants are eudicots, but they were rare in the Early Cretaceous. Potomacapnos apeleutheron is the first North Ame
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University of Maryland