Mount Saint Peter
Around 1765 the skull of a "Mosasaurus" was discovered here in a limestone quarry, one of the first recognised reptile fossils, which was later acquired by the Teylers Museum in Haarlem. A more famous "Mosasaurus" fossil was found between 1770 and 1774 but was confiscated by the French in 1794 and is now in the Muséum national d'Histoire naturelle in Paris. Later dinosaur remains were discovered here as well, belonging to "Betasuchus" and "Orthomerus", as well as turtles and fossils of smaller creatures of the sea.
Marcellus Formation
There are relatively sparse inclusions of fossilized marine fauna found in the Marcellus, but these fossils are still important to paleontology. For example, the Marcellus contains the oldest known diverse collection of thin-shelled mollusks still having well preserved shell microstructure.
It is also where goniatites, an extinct shelled swimmer similar to a squid, make their first appearance in the fossil record.
Life on land also enters the fossil record in the Marcellus, with the trunks of branchless conifer trees that floated out to sea to be preserved in the black shale.