In the

geological timescale The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronolo ...

, the Middle Devonian epoch (from 393.3 ± 1.2 million years ago to 382.7 ± 1.6 million years ago) occurred during the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

period, after the end of the Emsian age. The Middle Devonian epoch is subdivided into two stages: Eifelian and Givetian.

Life in the Middle Devonian

In the middle Devonian the armored jawless fish known as ostracoderms were declining in diversity and instead the jawed fish were thriving and increasing in diversity in both the oceans and freshwater. The shallow, warm, oxygen-depleted waters of Devonian inland lakes, surrounded by primitive plants, provided the environment necessary for certain early fish to develop essential characteristics such as well developed lungs, ability to crawl out of the water and onto the land for short periods of time, possibly in search of food which would be developed by the tetrapods later in the

Late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding ...

which are descendents of these early fish. The earliest

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

grew in the Middle Devonian ( Eifelian) time. This new environment was formed by cladoxylopsid trees including '' Calamophyton''. The Taghanic event took place near the end of the Middle Devonian.

References

* Middle Devonian {{geochronology-stub