430 million year-old Trilobite
The small crab-like animal fossil is a 430 million year-old Trilobite, one of Earth's first animals. It came from an ancient Silurian/Devonian period shallow coral sea, which once exited in what is today Western NY state. During this period, the global climate was much warmer than it is today and what is today New York, was close to equator. As a result, the warm shallow sea was the home to animals like this.
When this little guy was alive and swimming around, the Catskills were still at the bottom of the ocean, and not pushed up into mountains yet; it is embedded in shale stone.