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The earliest forms of amphibians evolved from lobe-finned fish in the Devonian Period, around 350 million years ago. These fish had strong, bony fins that allowed them to drag themselves on land, and some of them developed lungs for breathing air. These two adaptations were very helpful in their freshwater environments that were often stagnant and dried out. Eventually the bony fins of these fish evolved into limbs that became better suited for terrestrial locomotion over time. Early amphibians still spent most of their lives in water and always had to lay their soft eggs in water.
One of the earliest and most well known ancestors of amphibians (and all tetrapods in general) is a lobe-finned fish called Eusthenopteron. Although it never actually went on land, it still had four fins with bone structures homologous to all modern tetrapods, and also had internal nostrils and enfolded enamel found on primitive labyrinthodont amphibians.
Another important transitional form is Tiktaalik, who is an important link in the transition between lobe-finned fish and tetrapods. By the structure of its jointed fins, which contain wrist bones, it was probably one of the first fish to crawl on land. However, it only did so under certain circumstances and still spent almost all of its time in water. It had both gills and primitive lungs, and had a flattened head shaped like that of an amphibian's.
The earliest amphibians include Acanthostega and Icthyostega. Their primitive limbs contained digits, but were still poorly adapted for moving efficiently on land. Yet it was a good start, and they would be succeeded by labyrinthodonts such as Hynerpeton and Eryops, who are the ancestors of true amphibians.
The first modern amphibians emerged in the Carboniferous Period and had all the adaptations necessary to make them suitable for living both in water and on land. Amphibians became the dominant terrestrial vertebrates through most of the Carboniferous until they are replaced by their descendants, the reptiles.
What else can I help you with?
What evolutionary innovation is associated with reptiles?
The amniotic egg is a key evolutionary innovation associated with reptiles. This type of egg allowed reptiles to reproduce on land, away from water, which was a significant advantage for colonizing terrestrial environments.
What is an innovation associated with amphibians?
They are tetrapods.
Is metamorphis an evolutionary innovation associated with reptiles?
yes
What is an evolutionary innovation associated with cartilaginous fish such as sharks?
:OO
In biology an evolutionary innovation is also referred to as a?
Derived Characters.
What evolutionary innovation is associated with the simplest animals?
They went from simple colonies of cells (such as some groupings of bacteria) to multicellular creatures with some cell specialisation.
What groups is Innovation a characteristic most strongly associated with?
entrepernuers
Innovation is a characteristic mostly strongly associated with what group?
entreupranuership
What has the author Gian Carlo Cainarca written?
Gian Carlo Cainarca has written: 'An evolutionary pattern of innovation diffusion'
What evolutionary milestone involving animals occurred during the devonian period?
Sharks, lung fish, bony fish, trilobite, and,amphibians.
What term is most likely associated with clade?
monophyletic
Which evolutionary innovation was most significant in helping tetrapods move to dry terrestrial environments?
The evolution of limbs with digits was the most significant innovation that helped tetrapods move onto dry terrestrial environments. This adaptation allowed for weight support, better mobility, and the ability to navigate various terrains.
