A Jaw
Eggs that would not dry out
Greed?
The first land vertebrates appeared in the: Devonian
First were the plants and fungi, then came the arthropods, then finally the vertebrates.
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.
Around 400 to 350 million years ago the fist vertebras clambered onto land, they were tetrapods.
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).
A. Arthropods
Tetrapods
No, the first vertebrates evolved long before the Mesozoic. The first vertebrates, small jawless fish, evolved around 520 million years ago. Land animals had even evolved long before the Mesozoic Era.
There were many challenges that vertebrates had to overcome in order for them to colonize land habitats. Three of the most challenging tasks that vertebrates had was to learn how to eat the food on the land to sustain their energy and nutritional needs, how to breath, and how to defend themselves against predators.
Vertebrates are animals with a backbone, so some vertebrates live in water (e.g. fish) but others live on land (e.g. cows).
they all have backbones and they have to live in water or in land