Which Dinosaurs and Prehistoric Animals Lived in Maine?A brachiopod fossil, of the type common in Maine. Wikimedia Commons
Maine has one of the sparsest fossil records of any region in the U.S.: for a whopping 360 million years of its prehistory, from the late Carboniferous period to the very end of the Pleistocene epoch, this state was completely devoid of the types of sediments that preserve evidence of animal life. As a result, not only have no dinosaurs ever been discovered in the Pine Tree State, but neither have any megafauna mammals, since Maine was covered by impenetrable glaciers until about 20,000 years ago. Even still, there are some traces of fossil life in Maine, as you can learn by perusing the following slides. (See an interactive map of dinosaurs and prehistoric animals discovered in the United States.)02of 03
Early Paleozoic InvertebratesFossilized brachiopods. Wikimedia Commons
During the Ordovician, Silurian and Devonian periods--from about 500 to 360 million years ago--what was destined to become the state of Maine was mostly under water (it also happened to be located in the southern hemisphere; the earth's continents have drifted a long way since the Paleozoic Era!). For this reason, Maine's bedrock has yielded a rich diversity of small, ancient, easily fossilized marine animals, including brachiopods, gastropods, trilobites, crinoids and corals03of 03
Late Cenozoic InvertebratesNeptunea, a fossil mollusk of Maine. Maine Geological Survey
Most every other state in the union (with the obvious exception of Hawaii) bears some evidence of mammalian megafauna like Saber-Toothed Tigers or Giant Sloths, usually dating to the end of the Pleistocene epoch, about 12,000 years ago. Not Maine, unfortunately, which (thanks to its deep layers of impenetrable glaciers) hasn't yielded as much as a single Woolly Mammoth bone. Instead, you'll have to content yourself with the fossils of the Presumpscot Formation, which consist of 20,000-year-old species of barnacles, mussels, clams and scallops.