Answer:
Their was a distinctive change in the form of habitat from ocean, that is aquatic to forest that is terrestrial in the location.
Step-by-step explanation:
The trilobite were originally living in the ocean, they possessed the various adaptation needed to survive and multiply inside the water body only. The transition during the historical age through natural selection two million years ago Lead to the transformation and succession of the area under the study into a climax forest community. The process of succession however did not favour the trilobite which lead to the extinction of the species. Therefore, from the available data, the selected region had suffered from succession from aquatic to terrestrial habitat.