No , no , Amphibia is not most successful group of land vertebrates .It is least successful .
Amphibians
Aquatic larvae that breathe with gills and as terrestrial adults that breathe using lungs and skin
Amphibians are of the class Amphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Amphibians typically start out as larvae living in water.
the stamp act was most succeful
In most species Amphibians hatch as aquatic larvae with gills and then undergo metamorphosis into four-legged terrestrial adults with lungs for breathing air.
Amphibians hatch out of an egg with no shell.
reptiles and amphibians have the most in common
I think you're looking for the word amniotic egg. When terrestrial animals came onto land, they had to deal with dessication of embryos. Fish could lay their eggs in the water and amphibians usually followed suit. However, the amniotic eggs of most reptiles and some mammals have a shell. The shell significantly slows dehydration of the egg in the dry air, an adaptation that allowed reptiles to occupy a wider range of terrestrial environments than their closest relatives, the amphibians. Even today reptiles are found in many dry environments such as the desert, where as most amphibians are restricted to wet areas.
That is actually not true. The vast majority of animals, including vertebrates and invertebrates, are insects. All insects live on land. As for vertebrates, three of the seven classes are types of fish, and fish species equal the number of terrestrial vertebrate species, at approximately 32,000 types of fish compared with 10,000 reptiles, 10,000 birds, 5,000 mammals, and 7,000 amphibians.
Lungs Amphibians actually do have lungs. They lack most of the glands that we humans have.
Most amphibians are asymmetric. Although some appear to be symmetric.
Most amphibians just lay their eggs and leave. Although a few amphibians stay and guard, and most dart frogs carry of watch their eggs.