Ecosystems come and go as the Earth's outer crust makes transformative shifts. Scientists run computerized paleoclimate models to predict the past ecosystems but the new fossilized plant findings suggest that these previous models might have been off.
10 million-year-old fossil plants uncovered in the Andean Altiplano region suggest that the area was more humid at the time than previously assumed.
Researchers from the Smithsonian Tropical Research Institute (STRI) and several universities were staggered to uncover a huge fossilized tree buried in the high altitude, cold, grassy plains.
Camila Martinez from the STRI told “This tree and the hundreds of fossil wood, leaf and pollen samples we collected on the expedition, reveal that when these plants were alive the ecosystem was more humid—even more humid than climate models of the past predicted,” and added that “There is probably no comparable modern ecosystem, because temperatures were higher when these fossils were deposited 10 million years ago.”
The petrified (or permineralized) remains found by researchers is quite similar to what we would find in a low-altitude tropical forest of today. And indeed, 10 million years ago the altitude of the area was likely about half as low as today with 6560 ft (2000 mt) compared to its whopping current altitude of 13123 ft (4000 mt).
Younger fossils and the future awaiting us
5 million-year-old fossils from the same area confirm that the current ecosystem prevalent in the area settled around this age. Fossil findings from this era suggest that the rise of the area due to tectonic movements occurred around 5 million years ago. These younger findings were mostly grasses and herbs, in contrast with the older humid-climate-loving tree.
Carlos Jaramillo from the STRI, who also was the project leader told, “The fossil record in the region tells us two things: both the altitude and the vegetation changed dramatically over a relatively short period of time, supporting a hypothesis that suggests the tectonic uplift of this region occurred in rapid pulses,”
Martinez added, “Andean uplift played an important role in shaping the climate of South America, but the relationship between the rise of the Andes, local climates and vegetation is still not well understood,”. She also hypothesized that the rising atmospheric CO2 concentrations will approximate the conditions of 10 million years ago in the century ahead of us.
The research was published in Science Advances.