Evolution of tetrapods). These ancestral tetrapods had never left the water, and were thus primarily aquatic, like modern fishes. Secondary aquatic adaptations...

evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. Tetrapods (under...

partly aquatic. However, most tetrapod species today are amniotes, most of which are terrestrial tetrapods whose branch evolved from earlier tetrapods early...

fish, and weakly developed bones, which are seen in many other secondarily aquatic tetrapods. In 1940, paleontologists Alfred Romer and Llewellyn Ivor Price...

Polydactyly in early tetrapod aquatic animals, such as in Acanthostega gunnari (Jarvik 1952), one of an increasing number of genera of stem-tetrapods known from...

exclusive of other tetrapods. Instead, they consistute an evolutionary grade (a paraphyletic group), ancestral to living tetrapods such as lissamphibians...

includes finned and limbed tetrapods that are more closely related to living tetrapods than to living lungfishes." Tetrapods evolved from animals with...

some tetrapods started to evolve towards a reptilian condition. Some of these tetrapods (e.g. Archeria, Eogyrinus) were elongate, eel-like aquatic forms...

and rostrum of hupehsuchians have been compared to many other secondarily aquatic tetrapods such as plesiosaurs, whales, and the early marine bird Hesperornis...

other tetrapods somewhere during Romer's gap, when the adult tetrapods became fully terrestrial (some forms would later become secondarily aquatic). The...

sarcopterygians, prototetrapods, aquatic stem tetrapods (or "fishapods"), amphibian true tetrapods, and amniote tetrapods. Many morphological changes occurred...

has since been revealing a number of early tetrapods in the mid Carboniferous; "literally dozens of tetrapods came rolling out: Balanerpeton (a temnospondyl)...

condition of three phalanges-per-digit. This trait is characteristic of secondarily aquatic vertebrates with flippers. Hyperphalangy was present among extinct...

environments that they inhabit. For instance, dolphins that are secondarily adapted to an aquatic niche possess a considerably smaller subset of genes than...

locomotion, as seen in secondarily aquatic tetrapods. This unique combination of undulation and paddling is highly unusual for an aquatic reptile. The caniniform...

returned to a completely aquatic lifestyle. Primarily or exclusively aquatic animals have re-evolved from terrestrial tetrapods multiple times: examples...

broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds...

contains the clade of tetrapods (four-limbed vertebrates, mostly terrestrial), which are usually not considered fish. Some tetrapods, such as cetaceans and...

hypothesized that the secondary piscivores' diet change is due to an adaptation to maintain efficiency in their use of energy while growing. Aquatic genet Yellow...

themselves as terrestrial tetrapods in the succeeding Carboniferous.[citation needed] Amniotes branched from amphibious tetrapods early in the Carboniferous...

Reptiles, as commonly defined, are a group of tetrapods with an ectothermic ('cold-blooded') metabolism and amniotic development. Living reptiles comprise...

adaptation (both histological and microanatomical) of the tetrapod skeleton to a secondarily aquatic lifestyle. He is also interested in life history and population...

and more slender forelimb long bones to improve energetic efficiency. Tetrapods were initially understood to have first developed five digits as an ancestral...

echidnas probably was aquatic, and echidnas thus secondarily became terrestrial. Monotrematum sudamericanum is currently the oldest aquatic monotreme known...

only one. The lungs of lungfish are homologous to the lungs of tetrapods. As in tetrapods and bichirs, the lungs extend from the ventral surface of the...

tibia and fibula in the hindlimbs). This is a common feature of secondarily aquatic tetrapods in general, in which the limbs are adapted for steering and/or...

breathing air and eventually giving rise to amphibian tetrapods. These early tetrapods were large semi-aquatic piscivores and riparian ambush predators that hunt...

Discovered Clack, J.A. (2012). Gaining ground: the origin and evolution of tetrapods (2nd ed.). Bloomington, Indiana, USA.: Indiana University Press. ISBN 9780253356758...

some fully aquatic adult amphibians possess mechanosensitive systems comparable to the lateral line. The terrestrial tetrapods have secondarily lost their...

lungfishes and tetrapods, were believed to have become extinct at the end of the Cretaceous period. More closely related to tetrapods than to the ray-finned...