Cretaceous Period

Eon: Phanerozoic

Era: Mesozoic

Followed by: Paleocene Epoch

Preceded by: Jurassic Period

Formation: Mt. Laurel

Range: Cretaceous Period fossils in the Mid-Atlantic region are primarily found in spots along the C&D Canal in Delaware where dredge piles of sand from the bottom of the canal have been deposited.

Fossil Types: Marine invertebrates such as Belemnites (ancient squid pens), Exogyra costata pelecypods, and Pynchodonte mutabilis oysters.

Description:  The Cretaceous Period was much warmer than the mid-atlantic region is today.  It was known as the last stand of the dinosaurs, which dominated the landscape at that time.  A mass extinction at the end of the Cretaceous period exterminated the dinosaurs and many of the marine invertebrates as well.