Interconnectivity of Ancient and Modern Ecosystems

Studying ancient ecosystems alongside modern ecosystems helps paint a broader and more historically accurate concept of how Earth functions. As a student studying ecology, geology, and paleontology for the first time on this trip, gaining a broader understanding is valuable to forming my own foundation of earth sciences. Rock formations that were created hundreds of millions of years ago still stand today, and are therefore home to the modern ecosystems we see today.

One of our lessons about deep time focused on the different formations visible at Pitt’s Spring Creek Preserve. By analyzing the current rocks in the formations and the fossils present in each, we were able to rationalize what the ancient ecosystem might have looked like. For example, there’s an abundance of fish, ammonite, and bivalve fossils present across rock formations on the Preserve, suggesting that the land was once covered by a sea, which we now know as the Western Interior Seaway. Water covered the land we currently know as Wyoming during the Cretaceous Period (about 145-66 million years ago). This is in stark contrast to what we see on the Preserve today— a near desert ecosystem inhabited by white-tailed prairie dogs, pronghorns, and swift foxes. Despite these extreme differences, the dry prairie can still take us back in time to understand characteristics of the ancient inland sea, such as how factors like temperature, salinity, and other chemical compositions of the water changed throughout the sea’s history.

One of the specific members we studied was the Wall Creek Member, an area of sandstone across a ridge that currently holds many oceanic fossils. Scattered across the formation, ammonite fossils can be found. Ammonites were spiral shelled organisms that inhabited the Western Interior Seaway, and the high presence of them in the formation today suggests that sufficient oxygen must have been able to reach the bottom of the sea where ammonites resided.

The significant connection between ancient and modern ecosystems further emphasizes the importance of studying and properly preserving fossils so that future generations can also gain a complex and overarching understanding of our planet. The only way to fully understand deep time is through our modern world, and vice-versa.

Scaphite (a type of Ammonite characterized by its loose coils) fossil preserved in sandstone of the Wall Creek Member on Pitt’s Spring Creek Preserve.

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