Specialized paleontologists, called paleobotanists, study the earliest days of South America, Antarctica, Australia, Africa, and India through bits of leaf and petal impressions trapped in ancient stone. The hunt for fossilized tropical plants produces data that documents the breakup of the Pangea land mass and the continental drift that resulted in today's continents. It also gives us valuable clues about climate change and how that affects living systems. The rich material from the past may help us to predict the future. Does this Spark an idea?
Ferns from Before the Dinosaurs
Geologists in St. Louis County, Missouri have collected numerous fossils that reveal the tropical climate of the area 300 million years ago. Shale deposits in the northern part of the county hold perfectly preserved fossils of seed ferns. They are so detailed that they could be used to cast sculptures of the plants. The seed ferns flourished in tropical swamps during the Pennsylvanian Period, at the very beginning of the emergence of reptiles. Scientists have uncovered plant fossils that are the source of shallow coal beds in northern and western Missouri. The prehistoric ferns discovered at various sites are now extinct.
Ancient Bananas
Fifty-eight million years ago, Colombia had a rainforest teeming with gargantuan turtles, titanic snakes and prehistoric crocodiles. (reference 3)The time was the Paleocene Age and life was brutish, nasty and short. But the flora managed to survive. Scientists have discovered thousands of plant fossils in a huge open-pit coal mine -- an extraordinary rarity in a persistently tropical climate where traces of the past vanish like the afternoon cloudbursts. The fossils of avocados, palms, legumes and bananas represent a chance to explore how climate change affects a biosphere. Study of the fossils reveals that the tropics have cooled somewhat since the fossils were formed and that there was 60 to 80 percent less diversity in the Colombian rainforest flora of the Paleocene Age. The ancestors of the plants that grow there today may have been the remnants of the great dinosaur extinction or the earliest stages of plant diversification that led to the rainforest we have now.
Out of Africa
Most of the flowering plants that grow in the tropics, sub tropics and temperate zones of the world today had their origins in Africa but, until recently, information about those origins was a mystery. A site near Chilga in northwestern Ethiopia, is rich in plant fossils from 28 to 27 million years ago. The highly detailed flowers, wood, seed casts and leaf litter preserved in volcanic ash at the site provide clues to the climate history of the continent and the evolution of its woodlands, forests and savannas. For example, larger leaves mean a wetter climate; leaf litter reveals which plants coexisted in proximity and what an ancient forest may have looked like. Paleobotanists are now looking for information about rainfall, plant distribution, volcanic eruptions over the millennia and the origins of contemporary tropical African botany. Concurrent with the research is the development of a paleo-tourism industry to support the local villagers.
Tags: million years, plant fossils, climate change, fossils that, information about, leaf litter
