Devonian Life Sinks into Mass Extinction
The Reasons are Uncertain
Published in The EarthSphere Blog
Prologue
The Forgotten Origins series has noted life’s success in the Devonian Period as extensive adaptive radiation of plant and animal species occurred on land and at sea. But success comes at a price.
Extinction
Despite life’s advances on land and at sea during the Devonian, the circle of time completed a loop. Between about 383 and 359 million years ago, 70 to 80 percent of the species on the planet disappeared. However, evidence defining the cause of this catastrophe is sparse. Perhaps life was too successful for its own good. After all, the Anthropocene extinction indicates human beings may be too smart for their own good.
It’s important to place this extinction event into the proper time frame. The Late Devonian is divided into two stages: the Frasnian followed by the Famennian. These two stages span 24 million years. Paleontologists point to three periods in the Late Devonian where major changes occur in the fossil records; the beginning and end of the Frasnian and at the end of the Famennian. Large numbers of species disappeared from the geological records at these points in time.
