The earth's history has had a significant effect on the characteristics of its organisms and biomes. how was the carboniferous period different from the devonian period? a. forests and land plants evolved during the carboniferous period. b. there were vertebrates in the carboniferous period, but not in the devonian period. c. there were an increased number of land-based organisms in the carboniferous period. d. there were vertebrates with four legs in the devonian period, but not in the carboniferous.