Final answer:
Fossils and sedimentary rocks at Riversleigh have helped scientists understand the ecosystem of 15 mya by providing evidence of the species that lived during that time and their interactions. This information can be inferred from the types of fossils found and the characteristics of the sedimentary rocks.
Step-by-step explanation:
The well-preserved fossils and surrounding sedimentary rock at Riversleigh have been used by scientists to determine the ecosystem of 15 million years ago (mya). Fossils are important indicators of past ecosystems because they provide evidence of the species that lived during that time. By studying the fossils found at Riversleigh, scientists can identify the types of plants and animals that existed and make inferences about their interactions and the overall ecosystem.
For example, if scientists find the fossil remains of plant-eating animals, carnivorous animals, and plants that are commonly associated with a specific type of environment, they can infer that the ecosystem at Riversleigh 15 mya was a diverse one with a food chain comprised of different trophic levels.
Additionally, the sedimentary rocks at Riversleigh can provide information about the environmental conditions of the past. Different types of rocks can indicate whether an area was once a lake, river, or coastal environment, among others. By analyzing these rocks and their characteristics, scientists can further understand the ecosystem that existed at Riversleigh 15 mya.