Page "Fossil" Paragraph 42

Pseudofossils are visual patterns in rocks that are produced by naturally occurring geologic processes rather than biologic processes.

They can easily be mistaken for real fossils.

Some pseudofossils, such as dendrites, are formed by naturally occurring fissures in the rock that get filled up by percolating minerals.

Other types of pseudofossils are kidney ore ( round shapes in iron ore ) and moss agates, which look like moss or plant leaves.

Concretions, spherical or ovoid-shaped nodules found in some sedimentary strata, were once thought to be dinosaur eggs, and are often mistaken for fossils as well.