When a giant meteor crashed into Earth 66 million years ago, the impact pulverized cubic kilometers of rock and blasted the dust and debris into the Earth’s atmosphere. It was previously believed that sulfur from the impact and soot from the global fires that followed drove a global “impact winter” that killed off 75% of species on Earth, including the dinosaurs.
A new geology paper says that the die-off was additionally fueled by ultrafine dust created by the impact which filled the atmosphere and blocked sunlight for as long as 15 years. Plants were unable to photosynthesize and global temperatures were lowered by 15 degrees C (59 F).
650 million years ago, Earth was completely or almost completely frozen, according to the Snowball Earth Hypothesis. As the atmosphere changed and Earth warmed up, it heralded the beginning of the Ediacaran Period. The Ediacaran Period marks the first time multicellular life was widespread on the planet. It predates the more well-known Cambrian Period, when more complex life emerged, diversified, and flourished.
Life during the Ediacaran Period faced a mass extinction, and it was Earth’s first one.
We’ve long known a disaster took place about 66 million years ago, where in a geological instant, 75% of the plants and animals on Earth were wiped out, including all the land-roaming dinosaurs. But here’s a new detail about that event: Even though we can’t pinpoint exactly what year this disaster took place, we now know it happened during the springtime.
Humanity can have a love/hate relationship with itself, but there’s no denying that we’re the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as we. Several times, life had to drag itself back from near annihilation.
The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252 million years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct.
Most everybody knows that the dinosaurs perished rapidly in a tumultuous extinction, caused by an asteroid strike about 66 million years ago. But it looks like another extinction prior to the appearance of the dinosaurs paved the way for their long reign. That extinction took place about 233 million years ago.