Answer:
An ice age is a period when large expanses of ice sheets cover the land. Millions of years ago, an ice age occurred on Earth. Fossils of animals buried under this ice were obtained. The organisms were frozen solid shortly after death, which made them original tissue fossils. A mass extinction occurred during this period, which means that many species were wiped out.
Explanation:
Fossils of original tissues are remains or traces of animals and vegetables preserved in rocks or ice, in this case. Remains are animal parts (eg bones, teeth, scales) or plant (eg, trunks) and traces are evidence of their existence or their activities (eg footprints).
The exact definition of a mass extinction is arbitrary, but we can define it as a relatively common occurrence in the geological record that is characterized by the decrease of biodiversity through the exceptionally high extinction of several groups or, in other words, a reduction of many species of living beings.
