Calamites is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of 30–50 meters. They were components of the understories of coal swamps of the Carboniferous Period.
Calamites
Calamites sp. from the Estonian Museum of Natural History.
The foliage (Annularia) of Calamites
A diagram of a pith cast of Calamites
The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.
Selwyn Rock, South Australia, an exhumed glacial pavement of Permian age
Hercosestria cribrosa, a reef-forming productid brachiopod (Middle Permian, Glass Mountains, Texas)
Fossil and life restoration of Permocupes sojanensis, a permocupedid beetle from the Middle Permian of Russia
Edaphosaurus pogonias and Platyhystrix – Early Permian, North America and Europe
