Amniotes Synapsids (the group that would later include mammals) thrived and diversified greatly during the Cisuralian. Permian synapsids included some large members such as Dimetrodon. The special adaptations of synapsids enabled them to flourish in the drier climate of the Permian and they grew to dominate the vertebrates. A faunal turnover occurred around the transition between the Cisuralian and Guadalupian, with the decline of amphibians and the replacement of pelycosaurs (a paraphyletic group) with more advanced therapsids, although the decline of early synapsid clades was apparently a slow event that lasted about 20 Ma, from the Sakmarian to the end of the Kungurian. Predator-prey interactions among terrestrial synapsids became more dynamic. If terrestrial deposition ended around the end of the Cisuralian in North America and began in Russia during the early Guadalupian, a continuous record of the transition is not preserved. Uncertain dating has led to suggestions that there is a global hiatus in the terrestrial fossil record during the late Kungurian and early Roadian, referred to as "Olson's Gap" that obscures the nature of the transition. Other proposals have suggested that the North American and Russian records overlap, with the latest terrestrial North American deposition occurring during the Roadian, suggesting that there was an extinction event, dubbed "Olson's Extinction". The Middle Permian faunas of South Africa and Russia are dominated by therapsids, most abundantly by the diverse Dinocephalia. Dinocephalians become extinct at the end of the Middle Permian, during the Capitanian mass extinction event. Late Permian faunas are dominated by advanced therapsids such as the predatory sabertoothed gorgonopsians and herbivorous beaked dicynodonts, alongside large herbivorous pareiasaur parareptiles. The Archosauromorpha, the group of reptiles that would give rise to the pseudosuchians, dinosaurs, and pterosaurs in the following Triassic, first appeared and diversified during the Late Permian, including the first appearance of the Archosauriformes during the latest Permian. Cynodonts, the group of therapsids ancestral to modern mammals, first appeared and gained a worldwide distribution during the Late Permian. Another group of therapsids, the therocephalians (such as Lycosuchus), arose in the Middle Permian. There were no flying vertebrates, though the extinct lizard-like reptile family Weigeltisauridae from the Late Permian had extendable wings like modern gliding lizards, and are the oldest known gliding vertebrates.
Amniotes Synapsids (the group that would later include mammals) thrived and diversified greatly during the Cisuralian. Permian synapsids included some large members such as Dimetrodon. The special adaptations of synapsids enabled them to flourish in the drier climate of the Permian and they grew to dominate the vertebrates. A faunal turnover occurred around the tran!sition between the Cisuralian and Guadalupian, with the decline of amphibians and the replacement of pelycosaurs (a paraphyletic group) with more advanced therapsids, although the decline of early synapsid clades was apparently a slow event that lasted about 20 Ma, from the Sakmarian to the end of the Kungurian. Predator-prey interactions among terrestrial synapsids became more dynamic. If terrestrial deposition ended around the end of the Cisuralian in North America and began in Russia during the early Guadalupian, a continuous record of the transition is not preserved. Uncertain dating has led to suggestions that there is a global hiatus in the terrestrial fossil record during the late Kungurian and early Roadian, referred to as "Olson's Gap" that obscures the nature of the transition. Other proposa:ls have suggested that the North American and Russian records overlap, with the latest terrestrial North American deposition occurring during the Roadian, suggesting that there was an extinction event, dubbed "Olson's Extinction". The Middle Permian faunas of South Africa and Russia a:re dominated by therapsids, most abundantly by the diverse Dinocephalia. Dinocephalians become extinct at the end of the Middl!e Permian, during the Capitanian mass extinction event. Late Permian faunas are dominated by advanced therapsids such as the predatory sabertoothed gorgonopsians and herbivorous beaked dicynodonts, alongside large herbivorous pareiasaur parareptil.es. The Archosauromorpha, the group of reptiles that would give rise to the pseudosuchians, dinosaurs, and pterosaurs in the following Triassic, first appeared and diversified during the Late Permian, including the first appearance of the Archosauriformes during the latest Permian. Cynodonts, the group of therapsids ancestral to modern mammals, first appeared and gained a worldwide distribution during the Late Permian. Another group of therapsids, the therocephalians (such as Lycosuchus), arose in the Middle Permian. There were no flying vertebrates, though the extinct lizard-like reptile family Weigeltisauridae from the Late Permian had extendable wings like modern gliding lizards, and are the oldest known gliding vertebrates.