Search results
Results from the WOW.Com Content Network
The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. [1] Tetrapods (under the apomorphy-based definition used on this page) are categorized as animals in the biological superclass Tetrapoda, which includes all living and extinct amphibians, reptiles, birds, and mammals.
Only in the early Triassic, about a hundred million years after they conquered land, did the tympanic middle ear evolve (independently) in all the tetrapod lineages. [120] About fifty million years later (late Triassic), in mammals, the columella was reduced even further to become the stapes.
The group of lobe-finned fishes that were the ancestors of the tetrapod are grouped together as the Rhipidistia, [60] and the first tetrapods evolved from these fish over the relatively short timespan 385–360 Ma. The early tetrapod groups themselves are grouped as Labyrinthodontia.
The ancestors of true amniotes, such as Casineria kiddi, which lived about 340 million years ago, evolved from amphibian reptiliomorphs and resembled small lizards. At the late Devonian mass extinction (360 million years ago), all known tetrapods were essentially
The creature existed some 40 million years before dinosaurs evolved. Researchers have long examined such ancient predators to uncover the origins of tetrapods: four-legged animals that clambered onto land with fingers instead of fins and evolved to amphibians, birds and mammals including humans.
Other factors that caused aquatic tetrapods to spend more time on land caused the development of terrestrial hearing with the development of a tympanum within an otic notch and developed by convergent evolution at least three times. [10] There was also a change in the dermal bones of the skull in the aquatic tetrapods. [5]
The creature existed some 40 million years before dinosaurs evolved. Researchers have long examined such ancient predators to uncover the origins of tetrapods: four-legged animals that clambered ...
Those digits present in the lungfish fin eventually evolved into fingers and toes in tetrapods. "Tetrapod ancestors conquered land with limbs that evolved from fins, and were breathing air through ...