The sea started disappearing during the Carboniferous, and a rich floor developed on land, providing a habitat for the dinosaurs. Glaciers covered the state’s northern half during the Ice Age, while the southern part provided habitat for megafauna mammals like mastodons and mammoths. They were among the most prominent creatures, along with other prehistoric animals. Read on for more information on the 6 extinct animals that lived in Missouri.
1. The American Mastodon
The American mastodon is an extinct megafauna mammal of the genus Mammut and family Mammutidae that lived in North and Central America from the late Miocene or late Pliocene until its extinction about 11,000 years ago. It bore a close resemblance to elephants and mammoths, but mastodons were browsers, unlike mammoths, who were grazers. They also lived in herds and were primarily forest-dwelling creatures. Modern reconstructions based on partial and complete skeletal remains reveal that mastodons were shorter and thicker, typically 7 feet tall, and weighed approximately 8.6 to 12 tons. They had flat heads and long, brown shaggy fur with a hairy tail. Mastodons also had shorter and straighter tusks that measured up to 8 feet long. The Mastodon State Historic Site in Eastern Missouri is well-known for its American mastodon fossils dating back to the late Pleistocene epoch. Along with mastodon fossils, researchers also discovered crude stone spear points—direct proof that the Native Americans of Missouri hunted these plus-sized animals for their meat and pelts.
2. Falcatus
Falcatus was a chondrichthyan known as a “cladodont-toothed stethacanthus holocephalan.” It was often referred to as a shark, although its relatives were part of the order Symmoriiformes, meaning Falcatus were more closely related to Chimaeras than true sharks. Falcatus was a tiny, foot-long predator that lived during the early Carboniferous Period. Other members of its family include Cretacladoides from the Cretaceous of Austria and Ozarcus from the Carboniferous of Arkansas. Paleontologists established that Falcatus was sexually dimorphic. Males had narrow, sickle-shaped spines protruding from the top of their heads. It’s assumed that they used these spines to mate with females.
3. Hypsibema
Hypsibema is the official state dinosaur of Missouri. It was a duck-billed dinosaur that roamed Missouri’s vast plains and woodlands during the Late Cretaceous period, about 75 million years ago. Its fossils were first found in Missouri and North Carolina. At first, the remains were thought to belong to a small sauropod before they were later described as Hypsibema. According to paleontologists, Hypsibema was a type of dinosaur that duplicated or was typically a species of an already-existing genus.
4. Woolly Mammoth
The woolly mammoth is an extinct species of mammoth that inhabited the tundra steppe. This megafauna mammal was almost the same size as today’s African elephants. It’s estimated that males measured approximately 9 to 11 feet tall at the shoulder and weighed about 12,000 pounds, while females stood between 8.5 to 9.5 feet and weighed about 8,000 pounds. A newborn calf weighed around 200 pounds. Woolly mammoths were well adapted to cold environments during the last Ice Age. They were covered in fur (long guard hairs on the outer covering and a shorter undercoat). The ears and tails were short to reduce heat loss and frostbite. They had long, curved tusks, which they used for manipulating objects, fighting, and foraging. Woolly mammoth fossils are abundant, suggesting that these creatures were the most successful animals in their era, occupying many places. Remains of woolly mammoths have been discovered in Missouri.
5. Ancient Bison
The ancient bison is a direct relative of the modern American bison. It’s an extinct species of bison that inhabited North America during the Late Pleistocene. It was one of the largest common herbivores, weighing about 3,500 pounds. Furthermore, it grew up to 7.5 feet tall and 15 feet long. Its horns measured approximately 3 feet from tip to tip. The raging floods of the Missouri River have exposed numerous ancient bison fossils, including specimens as much as 10,000 years old, downstream from Oahe Dam. The skull collections are on display in various museums in Missouri.
6. Giant Beaver
The giant beaver, commonly known as Castoroides, is an extinct genus of bear-sized beavers that inhabited North America during the Pleistocene. The giant beavers were much larger than modern beavers. They measured approximately 6.2 feet long, though specimens of up to 7.2 feet have been recorded. Giant beavers weighed between 198 pounds and 276 pounds. One of the defining characteristics of the giant beavers was their long tails, which researchers believe may not have been paddle-shaped as in modern beavers. Their hind feet were also much larger than the present-day beavers. The giant beaver fossils were first discovered in a peat bog in Ohio in 1837. Since then, many specimens have been recorded across several states, including Missouri. Castoroides’ remains have been documented at Boney Springs in central Missouri.
