#permian

• Actinodon — A term with double structural valence; in paleontology, it defines a fossil genus of prehistoric amphibians (temnospondyls) from the Permian period, characterized by a dentition featuring distinct radiating striations. In modern zoology, it represents a species or genus of Asian salamanders (such as the stream salamanders related to the Actinodon / Pseudohynobius complex) whose microscopic dental structures are arranged as divergent rays on the palatal bones.
• Annularia — A fossil plant genus of the order Equisetales, characteristic of the Carboniferous and Permian periods, representing the star-shaped whorled foliage of the ancient trees known as Calamites. The linear or lanceolate leaves were structurally joined at the base into a distinct ring, forming a circular fossil imprint that provides crucial clues about the structure of Paleozoic swamp forests.
• Anthracosaur — A generic term for large fossil amphibians with transitional characteristics between amphibians and reptiles, which lived during the Paleozoic era, particularly during the Carboniferous and Permian periods. These primitive tetrapods were top predators in swamp ecosystems, featuring massive skulls, sharp labyrinthodont teeth, and a lifestyle adapted to both deep aquatic environments and early terrestrial movement.
• Artinskian — An age or stage in the Cisuralian epoch of the Permian period, geochronologically dated between approximately 290 and 283 million years ago; relating to this stage. In theoretical geology, the term describes an era marked by major climate shifts and massive marine sediment depositions, originally defined in the Ural Mountains region of Russia.
• Autunian — A transitional geological stage located at the base of the Lower Permian (or late Upper Carboniferous), defined by successions of oil shales rich in fossil flora (Callipteris conferta) historically researched in the basin of Autun, France; as an adjective, it refers to the formations, rocks, or fauna specific to this time interval.