Prehistoric New York

Geology & Fossils

As ancient North America drifted towards Africa, the land began to buckle, forming hills and mountains. The mighty Appalachian Mountains rose even before dinosaurs evolved. The sea drained away, leaving sea scorpion fossils high and dry.

Many millions of years later, the global climate cooled, plunging Earth into an “Ice Age.” Great sheets of ice covered much of New York. These continental glaciers erased much of New York’s fossil record, including most evidence of dinosaurs. They dug down to the Paleozoic rocks which entomb sea scorpion fossils. Other regions were buried under boulders and glacial debris.

Today, New York’s geology is complex. After all, it was shaped by continental collisions and volcanoes over a period of many millions of years, followed by Ice Age glaciers.

The Adirondack Mountains are part of the Canadian Shield, which can be thought of as North America’s “basement.” The rocks in this region, which were uncovered by glaciers, date to the Precambrian Period, before hard-shelled animals evolved. Marine animals that do not have hard shells are seldom fossilized. Therefore, the Adirondacks are among the worst places in the United States to look for fossils.

In the Great Lakes Plain of western New York are found sedimentary rocks representing the Ordovician, Silurian, and Devonian periods. Most fossils found here are of marine invertebrates that lived long before dinosaurs evolved, including sea scorpions.

Fossils of animals that lived during the Pleistocene Epoch, or Ice Age, are found in sediments throughout most of New York. They are most abundant in the Hudson-Champlain Valley. This valley was probably an important migration route for large Ice Age mammals such as mammoths.

New York’s official fossil was adopted at the suggestion of Dr. Donald W. Fisher, a retired State Paleontologist. The candidates he suggested included trilobites, the mastodon, and a snail that was the first New York fossil to be given a scientific name.