The Devonian Time Period

By: Kaitlyn Wade

Major Geologic Events of the Devonian Time Period

One major geologic event of the Devonian time period is, seas rose and fell over what is now North America. Another major geologic event of the Devonian time period is, the great supercontinent of Gondwana was headed steadily northward, away from the South Pole, and a second supercontinent began to form that straddled the Equator.

What Was The Climate Like In The Devonian Time Period?

The climate of the continental interior regions was very warm during the Devonian Period and generally quite dry.

What Were Some Of The Dominant Organisms During The Devonian Time Period?


Millipedes, centipedes and arachnids continued to diversify during the Devonian Period. The earliest known insect, Rhyniella praecursor, was a flightless hexapod with antennae and a segmented body.

Early tetrapods probably evolved from Lobe-finned fishes able to use their muscular fins to take advantage of the predator-free and food-rich environment of the new wetland ecosystems.

The earliest known tetrapod is Tiktaalik rosae. Dated from the mid-Devonian, this fossil creature is considered to be the link between the lobe-finned fishes and early amphibians. Tiktaalik was probably mostly aquatic, “walking” on the bottom of shallow water estuaries. It had a fish-like pelvis, but its hind limbs were larger and stronger than those in front, suggesting it was able to propel itself outside of an aquatic environment. It had a crocodile-like head, a moveable neck, and nostrils for breathing air.


Lycophytes, horsetails and ferns grew to large sizes and formed Earth’s first forests. By the end of the Devonian, progymnosperms such as Archaeopteris were the first successful trees. Archaeopteris could grow up to 98 feet (30 meters) tall with a trunk diameter of more than 3 feet. It had a softwood trunk similar to modern conifers that grew in sequential rings. It did not have true leaves but fern-like structures connected directly to the branches (lacking the stems of true leaves). There is evidence that they were deciduous, as the most common fossils are shed branches.

Reproduction was by male and female spores that are accepted as being the precursors to seed-bearing plants. By the end of the Devonian Period, the proliferation of plants increased the oxygen content of the atmosphere considerably, which was important for development of terrestrial animals. At the same time carbon dioxide (CO2), a greenhouse gas, was depleted from earlier levels. This may have contributed to the cooling climate and the extinction event at the end of the Devonian.

What Was The Environment Like During The Devonian Time Period?

It was made of forests made of living organisms, coral reefs, mountains, and ocean.
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What Are Some Things That Travelers Might Want To See During The Devonian Time Period?

People might want to see the coral reefs back then. People might also want to see the forests in the Devonian time period, and maybe what the mountains back then would look like.

What Should Travelers Pack For Comfort and Safety?

Travelers should pack their swimsuit, scuba gear, hiking gear, water bottles (lots of them), food (raw meat, fruits, vegetables), tent, wood (trees are made out of living organisms), lighters (5 or 6), stones (just in case there are none or very few), chest for food, and a thermos.

What Are Some Dangers Travelers Might Face?

People might face earthquakes, or early sharks. Early insects might be poisonous. The fish of the Devonian period had very large, strong jaws, so watch out for fish. There were no other animals on land besides insects, so no need to look out for those. There are unknown dangers in the oceans, however.