Middle Devonian

Increasing plant complexity

The Middle Devonian (393—383 Ma) is a fascinating time in plant evolution. During this time, plants begin to become more structurally complex, with elaborate anatomy, morphology, and increasing height. There are several groups and forms that appear on the landscape: ferns, "trees", woody vines, and possibly horsetails and proto-seed plants. The Middle Devonian occurs after the Emsian of the Early Devonian, and before the Frasnian of the Late Devonian.

Above: the arrangement of continents during the Middle Devonian (~390 Ma)

Geologic Age

393.3 – 382.7 Ma

Subdivisions

- Givetian
  - 387.7–382.7 Ma
- Eifelian
  - 393.3–387.7 Ma

Eon / Era / Period

Phanerozoic; Paleozoic; Devonian

What happened during this time?

Plants becoming taller and more complex in anatomy, branching, and reproduction strategies
Spore-bearing plants radiate during this time
- Advanced clubmosses, Protolepidodendrales, found in wet/swamp-like conditions
- Several early euphyllophytes, such as Chaleuria, Douaphyton, Kunia, Oocampsa, Pertica, and Plantanophyton found on the landscape
- Early fern-like plants, the Rhacophytales, also are found
- Iridopteridales appear, possibly the ancestor to the horsetails
- Pseudosporochnalean cladoxylopsids diversify
  - First tree-like plants appear in Givetian (Eospermatopteris)
- Aneurophytalean progymnosperms appear, growing as woody vines among taller plants
Seed-megaspores or proto-seeds appear during this time (e.g. Runcaria, Granditetrasporites, and Spermasporites)