How can the Zinsmeister Collection help us find out what the climate was like millions of years ago?

We can use fossils from the Zinsmeister collection to look at what types of changes in marine ecosystems occurred during changes in climate many millions of years ago. Fossils found in different layers of rock come from different periods in time. These layers each have different amounts and types of fossils, representing the different animals and plants that made up the environment when those layers were laid down. By comparing the fossils from the layers, as well as the rocks in those layers, we can understand what the climate was like at that time. For example, the types of fossil animals that come from Cretaceous rocks show that the Antarctic waters were much warmer during that time period than they are today. The types of fossilized organisms from the later Eocene layers of rock, however, show that the earth's temperatures were dropping, resulting in a cooler climate and a change in the types of animals living in these chilly waters.

An Eocene outcrop on Seymour Island. Image courtesy of W.J. Zinsmeister.