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Period: to
the Devonian
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First Insects
The first Insects evolved around the end of the Silurian period and the beginning of the Devonian period. The first insects resembled modern springtails, and later developed wings and mandibles -
Euramerica and Gondwana start moving towards each other
Around this point in time, The two large landmasses, Euramerica and Gondwana, begin moving towards each other. They will collide to form Pangea over 100 million years later -
Rhynie Chert
The Rhynie Chert is a sedimentary deposit preserving several species of plants and animals at the time. The oldest known insect, Rhyniognatha hirsti, was found in the deposits and scientists used this to determinee that insects developed during the late Silurian/ early Devonian -
Gondwana Forms
In the early Devonian, the continents of S. America, Africa, Antarctica and Australia morphed together to form the land mass called Gondwana. Euramerica also formed at around this time -
Euramerica Forms
Euramerica, or Laurussia, formed when Laurentia and Baltica collided, forming a new lands mass that started to drift towards Gondwana -
N. America collides with Africa
Present day N. America collided with Africa, beginning the formation of the modern day Appalachian Mountains in the Eastern US -
Vascular Plants cover Land
The Devonian climate was very humid and warm, and this led to the developement of vascular plants which promptly covered the land. The humidity in the air meant that plants were able to get further and further from large sources of water -
Ammonites form
In the seas, the first Ammonites developed. They had a protective shell as well as tentacles to catch prey -
Lobe Finned Fish Form
Lobe Finned Fishes are fishes with fleshy, lobelike fins extending from their bodies. These fins would later become the arms and legs of amphibians -
Lunged Fishes Evolve
Dipterus was one of the major lunged fishes to evolve during this period. Dipterus had lung sacks branching off of its throat that got air from the gills. During the Devonian Period, there were huge swings of floods and drought. During drought times, when lakes turned into ponds, the plants used all the oxygen in the little water that remained. A Dipterus that was stranded in such a pool could stick its head out of the water and get the air it needed to stay alive. -
Sharks start to evolve
Sharks were thought to be descended from the large and heavily armored Placoderms of the Silurian Period. The sharks lost the outside armor and didn't develope bones either, and instead got cartilage. The only fossil remains are the numerous teeth of the shakrs. -
First Amphibians
Powerful lobed fins of some fishes developed in arms and legs. these animals became the first Tetrapods, or four-footed animals. These tetrapods, however, still needed to stay wet despite developing lungs and were amphibians -
First trees develope
Around the mid-Devonian, a sudden explosion of trees and ferns developed. This was called the Devonian Explosion. The sudden greening of the land might have removed massive amounts of CO2, leading to later mass extinctions -
Kellwasser Event
The Kellwasser Event was one of two major mass extinctions at the end of the Devonian Period. The Kallwasser Event primarily affected marine organism. Reef building organism were almost completely wiped out; reef building would not commence until the Mesozoic Era. The population of Brachipods, Ammonites, and Trilobites were also decreased -
Hangenberg Event
The Hangenberg Event was the second of two mass extinctions at the end of the Devonian. It is responsible for further destruction of the Ammonites and Trilobites, as well as damaging jawed vertabrates, such as the Tetrapods. The Hangenberg event also wiped out all Placoderms and most of the lobe finned fishes. The Devonian Period ended with this mass extinction
