
Key Points:
- The Mississippi River is between 5.6 and 40 million years old, with some animal species calling the river home for millions of years.
- Alligators have been around for millions of years. Their first early ancestor emerged 245 million years ago. Millions of alligators can be found where the river travels through Louisiana.
- Bowfin are often called “primitive fish,” because they have some of the same characteristics as their early ancestors. They are also the only surviving species in the Amiidae family that first emerged in the Jurassic Period about 201.3 million to 145 years ago.
The Mississippi River is a unique river in North America. It’s about 2,350 miles long and is the 4th longest river in the entire world. The first place goes to the Nile River which is 4,160 miles long. While long, the Mississippi River is about 11 miles wide at the widest point. However, in some parts is as slender as 20 to 30 feet.
The Mississippi River is also old. Scientists estimate that the river is between 5.6 and 40 million years old, but its history spans 70 million years. With such an old age, you can imagine just how many creatures once called this river home.
While many of the species are extinct, but still found as fossils, some animals have been around for millions of years. Keep reading to meet some of the oldest animals that call the Mississippi River their home.

©iStock.com/ianpjones
Paddlefish

©Saran Jantraurai/Shutterstock.com
American paddlefish are native to the Mississippi River. It’s also called the Mississippi paddlefish. It’s a species of ray-finned fish. They are closely related to sturgeons. Paddlefish have been around for a long time. The oldest fossil recorded dates back 125 million years to the Early Cretaceous. While still commonly found in the river, they once moved more freely in unaltered conditions.
American paddlefish are not threatened but considered vulnerable. They are about 4.9 feet long and weigh 60 pounds. These unique fish have shark-like bodies. Typically, paddlefish live up to 60 years in the wild, and sometimes longer. These large fish are commonly found in deeper, low-current areas. Sadly, because of overfishing and habitat destruction, populations are declining. The infestation of zebra mussels in the Mississippi River also negatively affects these large shark-like fish.
Alligators

©Jim Schwabel/Shutterstock.com
Alligators are walking fossils. While alligators are not common in the state of Mississippi, you can still find them throughout the river in brackish water near swamps. However, Louisiana has at least 2 million alligators in Louisiana. Alligators have been around for millions of years. Their first early ancestor emerged 245 million years ago.
Alligators are large apex predators. American alligators are mainly found spread throughout southern states in swampy and marshland areas. They are massive, easily reaching past 14 feet long. In fact, the largest alligator caught in the world was 15 feet and 9 inches, but there are some reports of an alligator over 19 feet long in Louisiana.
Gulf Sturgeon

©Chase D’animulls/Shutterstock.com
Sturgeon are old fish. The oldest fossil ever found is from 100.5 million years ago to 66 million years ago during the Late Cretaceous. Gulf sturgeon is a subspecies of sturgeon living in the Gulf of Mexico and some rivers that drain into the gulf.
They are considered threatened and historically, scientists believe they lived from the Suwannee River on the western coast of Florida and to the Mississippi River. These fish are long and look like sharks. These unique fish also vary in size and weight depending on their diet. The gulf sturgeon mainly or only eat during the winter, fasting during warm months.
Catfish

©Kutikan/Shutterstock.com
Catfish are some of the oldest fish in the world. The first catfish fossil found so far dates back about 70 million years ago. Catfish are important to their environments and are a great source of protein and nutrients for us too.
Catfish doesn’t refer to a specific species, but instead a group of unique ray-finned fish known for their whisker-like prominent barbels. Some catfish species grow very big, including the Mekong giant catfish. Some catfish species though have become invasive species, specifically throughout Europe.
Bass

©Ryno Botha/Shutterstock.com
There is no shortage of bass fish in the Mississippi River. There is a favorite for anglers, attracting them from all over the world. Some common bass found in the Mississippi River includes largemouth bass, smallmouth bass, and striped bass. These large fish live about 5-6 years.
However, bass fish native to colder waters live closer to 20 years. In Texas, the oldest bass fossil ever was uncovered, and estimated that bass existed about 26 million years ago. The largest bass ever caught in the state of Mississippi weighed 18 pounds and 15 ounces. Anthony Denny caught this monster fish in Natchez State Park on December 31, 1992. What a great way to end the year!
Bull Sharks

©Fiona Ayerst/Shutterstock.com
Did you know bull sharks live in the Mississippi River? Bull sharks are one of the only sharks that can live in freshwater and saltwater conditions. Sometimes, they make their way into the Mississippi River from the Gulf of Mexico. Although not as common as you would think, it’s definitely something worth seeing. Bull sharks swim in shallow warm waters and weigh up to 290 pounds.
Although they aren’t the largest shark species, they are aggressive and fierce. Sharks have a long history, including the bull shark. There is still a lot that experts don’t know about these fascinating sharks. However, they are thought to be hundreds of millions of years old.
Bowfin

©Miroslav Halama/Shutterstock.com
Bowfin is old, often called “primitive fish,” because they have some of the same characteristics as their early ancestors. They are also the only surviving species in the Amiidae family. This family first emerged in the Jurassic Period about 201.3 million to 145 years ago.
The bowfin is native to the eastern United States and southeast Canada but is found all across North America. These highly aggressive ambush predators aren’t picky eaters and consume insects, fish, and crustaceans. Although bowfin fish live throughout the Mississippi River, their population has decreased.
Honorable Mention—Other Awesome Animals of the Mississippi River

©iStock.com/MarcQuebec
North American River Otter
The North American river otter is a semi-aquatic mammal that lives in the Mississippi River and its tributaries. It is an agile swimmer and is well-adapted to living in and around water. It has thick fur, webbed feet, and a long, muscular tail that helps propel it through the water.
Beavers
Beavers are semi-aquatic rodents that are native to the Mississippi River. They are well-known for their ability to build dams and lodges, which they use to provide shelter and safety from predators. Beavers feed mainly on tree bark and aquatic vegetation.
Coyotes
Coyotes are a wild canine species. They are adaptable and can survive in a variety of habitats, from grasslands to woodlands. Coyotes have sharp eyesight and hearing, as well as a strong sense of smell. They are omnivorous and feed on small mammals, insects, and plants.
White-Tailed Deer
White-tailed deer are a common mammal to see around the Mississippi River. They are well-known for their unique white tail, which is used to signal alarm. White-tailed deer feed mainly on grasses, leaves, and twigs.
Mountain Lions
Mountain lions are a large and powerful wild cat species. They are apex predators and feed mainly on deer, rabbits, and other small mammals. Mountain lions are solitary animals and prefer to remain hidden in dense vegetation or rocky outcrops.
Summary Of The 7 Oldest Animals That Call The Mississippi River Their Home
# | Animal | Date of Origin |
---|---|---|
1 | Paddlefish | 125 million years |
2 | Alligators | 245 million years ago |
3 | Gulf Sturgeon | 100.5 million years ago to 66 million years ago |
4 | Catfish | 70 million years ago |
5 | Bass | 26 million years ago |
6 | Bull Sharks | Thought to be hundreds of millions of years old |
7 | Bowfin | 201.3 million to 145 years ago |
FAQs (Frequently Asked Questions)
How old is the Mississippi River?
The Mississippi River is also old. Scientists estimate that the river is between 5.6 and 40 million years old, but its history spans 70 million years.
What animals are “walking fossils?”
Alligators are walking fossils. While alligators are not common in the state of Mississippi, you can still find them throughout the river in brackish water near swamps.
Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.