Some 90 percent of all sea life perished, along with 70 percent of land animals and most terrestrial plants. The researchers say the volcanic activity was likely going on before the impact, but was then fueled into a frenzy. The one-two punch, it seems, may be what's needed to precipitate the worst extinctions. The discovery, and the new technique used to make it, could lead scientists to find that some of the other 20 or so mass extinctions in the last billion years were also caused, or at least helped along, by cosmic collisions. The key to the new finding lay inside odd molecules known as Buckyballs, which scientists describe as looking somewhat like tiny soccer balls.
Buckyballs are complex carbon molecules more scientifically known as fullerenes.
The research team studied Buckyballs found in exposed soil layers known to be 251 million years old, from sites in China and Japan. Inside these fullerenes, the scientists found gases with a particular structure that could not have formed in our solar system. So these molecules are not only from beyond Earth, but from beyond our solar system, having formed in some distant primordial environment unlike the one created by our Sun. They would have then been incorporated into a comet when our solar system formed. Scientists say the object that slammed into Earth 251 million years ago, which may have been a comet, likely had a different composition than the presumed asteroid that hit the Yucatan Peninsula 65 million years ago, and hence left behind only small quantities of iridium.