The time of the dinosaurs was also the time of the fern plants
It is now widely accepted that the dinosaurs (and many other species of animals) were wiped off the face of the earth 65 million years ago, when a large meteorite hit the earth near what is now Yucatan, Mexico.
It is less clear what exactly happened to the vegetation as a result of the impact of the meteorite, whose diameter was at least 9.5 km. While there is evidence that much of the Northern Hemisphere was desolate as a result (as might be expected, since the meteorite struck from the southeast and spread its fragments northward), there is no sign of similar destruction of the flora in the south.
Now, however, scientists from Sweden and New Zealand have discovered evidence that deforestation was global. In an article in the journal "Science" they describe a "fern event" in the Southern Hemisphere, an event in which the various life forms of the plant almost disappear and some species of the fern dominate the dome. The time of occurrence corresponds to the time of the meteorite impact. Similar "fern events" were discovered earlier at sites in the Northern Hemisphere.
The scientists studied coal and sandstone deposits in a mine on the South Island of New Zealand. Analyzing pollen grains and spores in the layers dated before the meteorite hit, a wide variety of plant life was found, including conifers and other seedless trees, ferns and flower plants ("seed covered"). In the layers dated to the impact of the meteorite, the flower plants and the proportion of ferns disappear
is about 90 percent of the details found.
The researchers found that the flowering plants did not recover for more than a million years. In their opinion, this and other evidence supports the assumption that the meteorite impact severely disrupted the carbon cycle, and this led to sharp fluctuations in the climate for the next million years or so.
