Prince George's County Department of Parks and Recreation
Dinosaur Park
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Where in time is the Dinosaur Park?

The fossils at Dinosaur Park come from a time called the Cretaceous period, which lasted from 145 to 65 million years ago. This is relatively recent history compared to the 4.5 billion year age of the Earth, but is still long before the nearby marine deposits of Calvert County were formed (20 million years ago) or the earliest humans appeared on Earth (200 thousand years ago). 

In many ways, the Cretaceous period marked the birth of the modern world. During this time, the northern and southern landmasses of the prior period began to break up, forming the mosaic of continents and oceans we know today. The expanding oceans influenced the global climate, which became cooler and drier, with more pronounced seasons. This in turn led to the expansion of temperate forests, with trees such as oak, hickory and magnolia gaining prominence throughout North America. Meanwhile, flowering plants first became widespread in the Cretaceous period, joined by the first pollinating insects. The fossils found at Dinosaur Park help scientists understand how and why these important environmental transitions took place.