According to studies, Minnesota was an ocean over 500 million years ago. Fossils found in Minnesota during this period are typically primitive or even one-celled organisms. Paleontologists believe that Minnesota was a tropical sea during this time. Due to Minnesota’s unique geological history, scientists have found abundant fossils of marine invertebrates, including trilobites, brachiopods, and strange, shelled organisms. Some of the species of these fossils are unidentified, but scientists believe that modern animals evolved from these organisms. Here are eight extinct animals that lived in Minnesota:
1. Thaerodonta
Thaerodonta was a genus of animals that belonged to the Brachiopoda phylum. Brachiopods are animals that have hard upper and lower shells. There are several species from the Thaerodonta genus. According to research, specimens of Thaerodonta collected in Minnesota in 1949 displayed teeth. Paleontologists lack precise knowledge about Thaerodonta, but various species were collected from Fillmore County, Minnesota, in the 19th century. In fact, this set of collections was referred to as the Thaerodonta-Oniella community.
2. Isotelus
Isotelus is a genus of the Trilobita class, to which extinct marine arthropods belonged. It was relatively common in North America. Isotelus Rex, the world’s largest trilobite, was found in Manitoba, Canada. It was 27.5 inches (70 cm) long, making it roughly 70% larger than the most complete fossil trilobite ever discovered. Isotelus were semi-infaunal predators and benthic feeders, which means they were either actively or passively sieving organisms or small food particles by partially burrowing into the bottom sediments. In 1998, fossils of several species in the genus Isotelus were found in the Maquoketa Formation in Minnesota.
3. Stenolaemata
Stenolaemata were simple, aquatic invertebrates that lived in the ocean. They were colonial marine animals that looked like plants. They were a class of suspension feeders, which means they were stationary but survived by feeding on tiny organisms while suspended in water. Today, there are more than 600 species of Stenolaemata. These species are believed to originate from unclassified fossils of Stenolaemata collected in Minnesota in 2001. Zack Krug’s collection of Stenolaemata fossils is from St. Peter Sandstone Formation in Minnesota. These fossils lived approximately 468.1 to 452.5 million years ago during the Ordovician Period.
4. Conodont
Conondots are an extinct class of jawless vertebrates that look similar to eels. Their bodies were soft flesh, making them hard to be fossilized. Because of their physique, most fossils found are oral skeletons, specifically their teeth. Some of the Conodonts’ fossils were collected in St. Peter Sandstone Formation in Minnesota in the 19th century.
5. Bison occidentalis
Bison occidentalis is an extinct species of bison that lived in Minnesota during the Last Glacial Period, 115,000 to 11,700 years ago. Bison occidentalis was much bigger than modern bison. The fossilized bones of Bison occidentalis were found by a farmer in an old lake bed in 1934. Paleontologists collected more than 1,500 bones of the species from the site.
6. Woolly Mammoth
Woolly mammoths are extinct herbivorous mammals that lived throughout the Pleistocene Epoch. They were the descendants of elephants, but they were much bigger and heavier than the modern surviving ones. There are other species from the Mammuthus genus, but the woolly mammoth was distinct because it had visible fur, hence the name.
7. Mastodon
Mastodons are species from the Mammutidae family, which woolly mammoths and modern elephants are from. The remains of mastodons in Minnesota were excavated from a gravel bank in Northfield in 1879. Paleontologists reported similar findings in Winona County, Minnesota, and Stillwater, Washington.
8. Giant Beavers
Giant beavers that were found in Minnesota are scientifically called Castoroides ohioensis. Castoroides ohioensis is a species related to rodents. However, they were far from the size of rats, squirrels, porcupines, or even the modern beavers. Extinct giant beavers that used to live in Minnesota were as enormous as modern bears. In 1879, the first specimen of a giant beaver was found in Minnesota, consisting of a jaw 11.2 inches (28.4 cm) long. According to research, Castoroides ohioensis may have reached 8 to 9 feet (96 to 108 inches) long and weighed 500 lbs (226.7 kg). Despite their large size, they looked similar to beavers.
