Although ammonites have been extinct for 65 million years, newly published data based on 35 years of field work and analysis is providing invaluable insights into their paleobiology. Ammonites, shelled mollusks closely related to modern day nautilus and squids, inhabited the oceans for nearly 350 million years. Specimens found in the rock record of the ancient seaway that covered North America during the Cretaceous Period demonstrate that these animals thrived at cold methane seeps at the bottom of the sea, consumed small prey, and often survived predation attempts.