![Micrograph images of Two fossil dinoflagellates in a rock](http://static.sciencelearn.org.nz/images/images/000/001/802/full/Dinoflagellate-fossils20160826-15711-v9qzjo.jpg?1674166891)
The presence of these two fossil dinoflagellates in a rock can help date it to the late Cretaceous. The fossils are only about 200µm long.
Micrograph by Poul Schioler.
The presence of these two fossil dinoflagellates in a rock can help date it to the late Cretaceous. The fossils are only about 200µm long.
Micrograph by Poul Schioler.