While Mississippi may not be the first place that comes to mind for dinosaur discoveries, the state holds a noteworthy paleontological past. Evidence indicates that various dinosaurs once inhabited the ancient lands of what is now Mississippi. Though complete skeletons are rare, fragmented remains and environmental clues provide insight into the prehistoric creatures that once roamed this region. This article explores the unique conditions that shaped Mississippi’s ancient ecosystems and the types of dinosaurs and other large prehistoric animals that lived there.
Ancient Mississippi’s Landscape
During the Late Cretaceous epoch (approximately 85 to 66 million years ago), Mississippi’s geography differed significantly from today. Much of the state was submerged under a shallow, warm tropical sea, part of a larger inland seaway that bisected North America. Terrestrial environments, including coastal plains and islands, were primarily limited to the northeastern part of the state.
This marine environment heavily influenced the types of fossils preserved. While the deep sea covered much of the region, coastal areas and landmasses supported a range of life, allowing some terrestrial animals to thrive. The interaction between land and sea allowed for the preservation of both marine and terrestrial creature remains.
Key Dinosaur Discoveries
Dinosaur evidence in Mississippi primarily consists of isolated bones and teeth, as complete skeletons are uncommon finds. Hadrosaurs, also known as duck-billed dinosaurs, are the most frequently discovered dinosaur remains in the state. These plant-eating dinosaurs were a prominent group during the Late Cretaceous period.
A significant hadrosaur discovery occurred in 2007 near Booneville, where a nearly complete specimen, estimated to be 25-26 feet long, was found and remains largely buried. Researchers are currently using advanced 3D analysis techniques to identify the specific species of this hadrosaur.
Beyond hadrosaurs, fossil evidence also points to the presence of other dinosaur groups. Isolated teeth from tyrannosaurs (large meat-eating dinosaurs) have been recovered. Armored dinosaurs known as Nodosaurids, smaller raptor-like dromaeosaurs, and ostrich-mimic ornithomimosaurs have been identified. A rare find in 2016 included a tooth from a ceratopsian (horned dinosaur), which was only the third such discovery east of the Mississippi River. The preservation of these terrestrial dinosaur remains often occurs when carcasses were swept into the ancient seas by storms or floods, leading to their deposition in marine sediments.
Other Prehistoric Life
Given Mississippi’s extensive ancient marine environment, the fossil record is particularly rich with non-dinosaur prehistoric creatures that inhabited the seas. Mosasaurs, a group of large marine lizards, were abundant apex predators in the Late Cretaceous oceans. Some reached lengths of up to 50 feet, with jaws filled with dagger-like teeth designed for hunting fish, shellfish, and even other marine reptiles. A recent discovery includes a large vertebra from Mosasaurus hoffmannii, which could represent one of the largest mosasaurs ever found in the state.
Plesiosaurs, another type of long-necked marine reptile, also swam in these ancient waters. The fossilized teeth of ancient sharks are commonly found across the state, particularly in northeastern Mississippi. These diverse marine predators thrived in the warm, shallow seas that covered much of Mississippi during the age of dinosaurs.
While not a dinosaur or a marine reptile, Basilosaurus cetoides holds the distinction of being Mississippi’s state fossil. This ancient whale, a marine mammal that lived during the Late Eocene epoch (after the dinosaurs), could grow to be up to 60 feet long and was initially mistaken for a reptile due to its serpentine appearance.