The Devonian (410-355 mya)

Art copyrighted 1995 by Stephen Greb

Originally named for Devonshire England where it was first examined, the Devonian encompasses a time frame of 55 million years, although sources disagree on the exact dates. The period, while not dominant on the surface in KY, provides an excellent cross-section of Paleozoic Era Phyla. Included in the Devonian are Porifera (sponges) Cnidaria (corals) Bryozoa Brachiopoda Mollusca Arthropoda and Echinodermata.

While not a focus of this project, The Devonian is also known as the Age of Fish. Fish diversified greatly during the period and include benthic armored ostracoderms in the early Devonian, the first jawed fish in the middle Devonian, and lobed fish-the precursor to tetrapods in the late stages of the Period. Also, the first air-breathing arthropods appeared during this time, but are not seen in the aquatic fossil beds of Kentucky. Project Area from late Early Devonian to Middle Devonian. This time frame is more specifically known as the Emsian and Eifelian Age - 387 to about 380 million years ago.

From a Tectonic standpoint, the Devonian is defined by a three-plate collision between America, Eurasia, and Gondwanaland. This created what is known in this hemisphere as the Acadian orogony.

For maps of the Earth during the Devonian click here