Why is it rare for animal to be presevered as a fossil?

The preservation of animals as fossils is rare primarily due to the conditions required for fossilization, which typically involve rapid burial and low oxygen environments that prevent decomposition. Soft tissues are particularly unlikely to fossilize, as they decay quickly, while hard parts like bones and shells are more durable but still need specific conditions to survive over time. Additionally, geological processes can destroy fossils before they are discovered, further limiting the number of animal fossils available for study.