The end of the Devonian Period marked some incredible changes to our planet’s surface, and it was an interesting time in Earth’s history. To understand this, we need to first look at the progress of life during the Devonian. Back then, plants were small and primitive compared to today’s plants, but later became the dominant form of complex life on land over the course of the Devonian Period. At the end of the Devonian Period, huge forests were likely a common sight.
Sandstone with ripples created by a river current that flowed back during the Late Devonian.
Dark and thinner siltstone and mudstone layers hint at a marine environment during the Carboniferous.
However, around the transition from the Devonian to the Carboniferous, many species went extinct. We are not entirely sure how or when it happened, but there are many theories. One of these involves climate change, potentially and ironically caused by the success of plants on land. What we do know is that a great deal of species and groups of species small and large simply ceased to exist. This is one of the five large mass extinctions that we know of in geological history, the last of these being that which killed the dinosaurs.
In fact, it was likely that several mass extinctions occurred within a few million years around this boundary. What we do know is that many species or groups of organisms existing throughout the Devonian simply disappeared never to appear again. Whatever happened, some species managed to thrive. The crinoids or sea lilies that we explored in our limestones had a fantastic time and diversified a further into the Carboniferous. It is rare that we get to see a well-exposed boundary between two geological time periods, especially one that takes place through such incredible global events.
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