How can scientists conclude that worms existed hundreds of years ago?

Scientists can conclude that worms existed hundreds of years ago by studying fossilized remains and preserved specimens found in sediment layers. Additionally, they analyze soil samples for biological markers, such as worm casts or burrows, which indicate past worm activity. Historical records and ecological studies also provide insights into the presence of worms in various environments over time. Together, these methods help reconstruct the historical timeline of worm existence.