1. Palaentology is the study of fossils.
2. The process of fossilization takes a very long period of time. In order to study the fossil, the land is excavated.
3. Fossils are collected from different levels of depths. A systematic study of these fossils and its occurance revealed that the deepest layers were found to have fossils of invertebrates.
4. In layers above them were found prehistoric fish-like animals, amphibians, reptiles, birds and mammals respectively in that order.
5. This suggests that perhaps this was the oder in which the animals appeared on the earth.
2. The process of fossilization takes a very long period of time. In order to study the fossil, the land is excavated.
3. Fossils are collected from different levels of depths. A systematic study of these fossils and its occurance revealed that the deepest layers were found to have fossils of invertebrates.
4. In layers above them were found prehistoric fish-like animals, amphibians, reptiles, birds and mammals respectively in that order.
5. This suggests that perhaps this was the oder in which the animals appeared on the earth.
