In July 2003, paleontologists were on a routine investigation of fossil sites in Wind Cave National Park when something caught their attention. It was a very large set of fossil teeth. Careful study revealed that these were the teeth of an ancient hornless rhinoceros - a Subhyracodon occidentalis.
Maine ocean islands provide the only nesting sites for Atlantic puffins in the United States. Eastern Egg Rock in the midcoast region, Seal Island and Matinicus Rock at the mouth of Penobscot Bay, and Machias Seal Island and Petit Manan Island off the downeast coast provide habitat for more than 4,000 puffins each summer.