Year: circa 400,000,000 million years ago
While New York State is not a treasure house of dinosaur fossils it is a treasure house of early marine fossils predating the Mesozoic Era. During the time before the dinosaurs New York was covered, uncovered, covered again, uncovered again, and covered yet again by a succession of shallow seas teeming with various forms of life. As the advance and retreat of these seas took millions of years, multiple layers of the flora and fauna of these successive eras may be found within New York State's boundaries.
The seas that covered New York State contained vast coral reefs and submarine thickets of sea lilies that provided homes for armored squid and giant sea scorpions (the official State Fossil). Trilobites in their thousands of subspecies teemed in these warm water oceans. The author Mark Twain collected brachiopods (sometimes called butterfly stones) on his Elmira farm.
Upstate is so rich with fossil remains that a 19th Century survey of New York State fossils by James Hall, the first State Paleontologist, ran to 13 large volumes.