But the exact periods in history when it happened ... An estimated 90 percent of all animal species on the Earth were wiped out. Many groups of insects and mammal-like reptiles disappeared.

All three of orbital cycles — called Milankovitch ... Model, proxy and isotopic perspectives on the East African Humid Period. Earth and Planetary Science Letters 307, 103-112 (2011).

While this provides some evidence that at least one part of the continental interior was covered in ice during the snowball Earth period, that doesn't necessarily apply to all areas of all continents.

However, all 21 of the craters are located within ... As one of the coldest periods in Earth's history, the Hirnantian Icehouse played a crucial role in the second-largest mass extinction in ...

And the period (as it is now known, since the realisation that Earth is far older than the 6,000 ... Trilobites would not have been tasty. All shell and legs Back to Pangaea.