What Caused The Devonian Period To Start? Leading hypotheses include changes in sea level and ocean anoxia, possibly triggered by global cooling or oceanic volcanism. The impact of a comet or another extraterrestrial body has also been suggested, such as the Siljan Ring event in Sweden. What first appeared in the Devonian Period? The first
How Was The Triassic Period Unique? The Triassic Period was a time of great change. Bookended by extinctions, this era saw huge shifts in the diversity and dominance of life on Earth, ushering in the appearance of many well-known groups of animals that would go on to rule the planet for tens of millions of
What Happened To The Brachiopods? At the end of the Paleozoic, however, they were decimated in the mass extinction that marks the end of the Permian Period, about 252 million years ago. Although some brachiopods survived and their descendants live in today’s oceans, they never achieved their former abundance and diversity. How did brachiopods survive?