During the carboniferous period, which occurred approximately 360 to 300 million years ago, most of earth was covered in dense rainforests. these rainforests were sustained by a humid and tropical climate that lasted for most of the carboniferous period. at the end of the period, earth's climate became much colder and drier, leading to a wide-scale collapse of the rainforests and a significant loss of vegetation.
how might the collapse of the carboniferous rainforests have affected earth's carbon cycle?

During the Carboniferous period the Earth was very warm and moist, covered with dense forests. When the Carboniferous rainforests collapsed, most of the trees were immediately covered with mud, as everything was wet and swampy. The trees are one of the biggest natural storage for carbon. Because the trees and the large amounts of carbon trapped in them were covered, lot of carbon was removed from the atmosphere, thus from the carbon cycle. Gradually, the carbon from the trees ended up deep into the ground, which eventually turned into coal. The removal of such a high quantity of carbon from the carbon cycle resulted in a reduced Greenhouse effect, which in turn made the planet much colder.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

a and c are the answeres