Devonian Life on Land

Catskills Delta and Fossils from Near Gilboa

Catskill Delta

During the Devonian, the eastern part of New York state was the edge of the sea, with the foothills of the Acadian mountains leading into a wide river delta. The mountains, uplifted by tectonic forces, eroded and shed sediments westward across the ancient “Catskill Delta” into the sea that covered Central and Western New York. Devonian rocks from the Catskills show what life was like on land at this time, and provide a key window into ancient plant and animal life.

Plants originated on land during the Ordovician Period, and grew in diversity during the Silurian Period. Early plants were tiny and closely tied to nearby water for their reproduction. The evolution of seeds during the Devonian allowed plants to reproduce farther from water.

Earth’s first forests evolved during the Devonian Period. Much of the earliest evidence for this comes from 387-million-year-old rocks from Gilboa, in Schoharie County, New York. Gilboa is a small community, about 50 miles southwest of Albany. During the Devonian, Gilboa was located between tall mountains to the east and an inland sea to the west.

Gilboa Fossil Forest

The Gilboa fossil forest was discovered in 1869 when workmen quarrying rock along Schoharie Creek discovered several fossilized tree stumps. These fossils caught the attention of New York State Paleontologist James Hall, who arranged for them to be taken to the State Museum in Albany. Construction of the Gilboa Dam on Schoharie Creek began in 1917. Dozens of additional stumps were discovered in nearby rock that was being quarried to construct the dam. The extinct trees represented by these fossil stumps were named Eospermatopteris.