Context: The climatic changes of the late Jurassic and Cretaceous provided for further adaptive radiation. The Jurassic was the height of archosaur diversity, and the first birds and eutherian mammals also appeared. Angiosperms radiated sometime in the early Cretaceous, first in the tropics, but the even temperature gradient allowed them to spread toward the poles throughout the period. By the end of the Cretaceous, angiosperms dominated tree floras in many areas, although some evidence suggests that biomass was still dominated by cycad and ferns until after the Cretaceous–Paleogene extinction.

Question: What event produced further adaptations during  the Jurassic and Cretaceous periods?
Answer: climatic changes

Question: When was the top of archosaur diversity?
Answer: Jurassic

Question: What species spread towards the poles during the Jurassic?
Answer: Angiosperms

Question: What species dominated many tree floras by the end of the Cretaceous period?
Answer: angiosperms

Question: What types of species are thought to still have been dominate until after the extinction?
Answer: cycad and ferns

Question: What event stunted adaptions during the Jurassic?
Answer: Unanswerable

Question: When was the bottom of archosaur diversity?
Answer: Unanswerable

Question: The temperature gradient prevented what land species growth?
Answer: Unanswerable

Question: What prevented the spread of angiosperms towards the poles?
Answer: Unanswerable

Question: What types of species are thought to have died before the extinction?
Answer: Unanswerable