Answer:
The answer is:
D. the radiation of herbivores such as grazing animals
Explanation:
Oligocene and Miocene Epochs:
- The Oligocene epoch is characterized by temperate and subtropical climatic conditions which favored the expansion of grasses and reduced forest cover.
- The Miocene epoch, which succeeded the Oligocene era, is attributed to changes in global circulation due to global warming of the climate followed by global cooling towards the end.
The Oligocence and Miocene epoch are both attributed to the expansion of grasslands and savannah. Both eras marked rapid and drastic evolutionary changes in grazing mammals and herbivores. Diverse groups of grazing mammals lived throughout these eras. For example, the largest herbivore and land mammal of all time, Indricotherium (a sort of giant hornless rhinoceros), was present in the Oligocene era.
Similarly, the Oligocene era in North America favored the rapid radiation of primitive horses.
