First Devonian Forests on Earth: Appearance, Composition of Plants, Types of Forest Ecosystems, and Their Distribution

The article considers the appearance, composition, types, and distribution of the first Devonian fossil forests on Earth, finds of which are extremely rare. There are five known localities: three in the Middle Devonian (Middle Eifelian locality Lindlar in Germany; two Upper Givetian localities Cairo and Gilboa in the USA), and two in the Upper Devonian (Lower Frasnian locality Munindalen on Svalbard in Norway and the Upper Famennian locality Xinhang in China). The terms fossil forest, forests community, and a type of fossil forest, not mentioned by previous researchers, are proposed, and a detailed plan for their description is recommended (formulations are presented only for remains in the status in situ). The stratigraphic sequence of the first forests in the Eifelian–Late Devonian of the Earth’s history, taking into account recently published data, is presented. Two types of forests have been identified with indication of the dominant genera in each type: the cladoxylopsid type, common in the Middle Devonian, and the lycopodiophyte type, typical of the Upper Devonian. A key role of cladoxylopsid ferns in the creation of original arboreal forests due to advantages in the organization of their conducting system is shown.