Mammals,birds and reptiles are fully adapted to life on land. Fish live in water and amphibians start their life in water, then live on land.
You could say that as amphibians need to at least use water for reproductive purposes.
No because you are gay(:
Mammals
false
Vertebrates came first... all of those other creatures are vertebrates.. prior to the evolution of the spine (vertebrae) there were no fish, reptiles, mammals birds... nothing like them..
Amphibians were the first vertebrates that came out of the water. The first vertebrates that could live outside of the water though were reptiles. or class reptilia this was during the Carboniferous period.
A duodenum (Assuming this is what you meant) is the first part/section of the small intestine that is found in vertebrates. (Reptiles, birds, mammas, etc.)
Plato Users: A. Amniotic Egg, and Dry Scaly Skin.
All land vertebrates (including humans) can trace their origins back to the first fish that began crawling on the land using their strong, jointed fins. Eventually, the fish became more adapted to dry land and became amphibians. However, these amphibians still laid their eggs in water, and their young were tadpoles that spent all their time in water. The first true land vertebrates were reptiles, who were born on land and spent almost all their time on land. A small group of these reptiles became warmblooded and started growing hair, so they became the first mammals. Mammals remained small until the extinction of the dinosaurs, when they were given more room to grow, diversify, and give rise to humans.
One is that the first reptiles (not dinosaurs!) appeared. The land during this peiod was swamp-forests.
The first land vertebrates appeared in the: Devonian
The first vertebrates to come onto land were fish-like animals that developed lungs and could thus stay on land for extended periods. These evolved into terrestrial amphibians (although many amphibians require water in which to lay eggs, and some are aquatic).
The first and most basic distinction is to separate them into mammals, birds, reptiles and amphibians. But, every species is different and in a species there can be subspecies with their own differences. So, there are as many differences as there are species.
The first vertebrates to live on land did not come out of the sea until 370 billion years ago. Those first land vertebrates were amphibians. Several structural changes in the bodies of amphibians occurred as they adapted to life on land. Amphibians had moist breathing sacs -lungs- which allowed the animals to absorb oxygen from air. The limbs of amphibians are thought to have derived from the bones of fish fins. Because of there strong flexible internal skeletons the bodies of vertebrates can be much larger than those of insects. While amphibians were well adapted tp their environment, a new group had evolved from them. They evolved to reptiles but we are on the subject of the first land animal so that's that.
The first type of heart is the simple two chambered heart, which is found in fish. The second is the third chamber heart, which is found in amphibians and reptiles. Mammals and birds have four chambered hearts.
reptiles because of the dinosaurs