File:Edmontonia was an "armored dinosaur" of the group Ankylosauria.jpg|
Edmontonia was bulky and tank-like at roughly 6.6 m (22 ft) long and 2m (6 ft) high. It had small, ridged bony plates on its back and head and many sharp spikes along its back and tail. The four largest spikes jutted out from the shoulders on each side, two of which were split into subspines in some specimens. Its skull had a pear-like shape when viewed from above.
Without question, the best-known and most popular fossil organisms are the dinosaurs. Many people wonder if dinosaurs have been found in Ohio or lived in Ohio. During the Mesozoic Era, when dinosaurs and other reptiles were the dominant forms of life, Ohio was above sea level as an upland land mass. Undoubtedly, dinosaurs roamed the Ohio land but erosion, rather than deposition was the dominant geologic force. Dinosaur remains that may have been entombed in lake or river sediments were destroyed during the 300-million-year long interval of erosion that removed huge amounts of rock. Therefore, unless an isolated deposit of Mesozoicrocks is discovered in Ohio, no dinosaur remains will ever be found in the state.