Top 10 Prehistoric River Monsters

In honor of Animal Planet's River Monsters. Not all animals are fish, but all reside in freshwater...

10. Xenacanthus

This terrifying, 10 foot freshwater shark patrolled our Earth over 200 million years ago. Also known as the eel-shark, the Xenacanthus was one of the very first river monsters. Oh, and PS, each of it's teeth had two points to it.

9. Megapiranha

It's exactly what it sounds like. A huge piranha. This fearsome fish lived some 10 million years ago and reached around 3 feet. Sadly, it's only known by a single jaw bone, hence why it's low on the list(not a lot of info on it).

8. Onchopristis

At over 23 feet long and with a nose like a saw(oh, this saw was 8 feet Onchopristis was easily one of the baddest fish in the rivers. This fish had to be tough. It lived around 110 million years ago alongside Spinosaurus, one of the greatest fisherman of all time.

7. Pannoniasaurus

Pannoniasaurus is the first known freshwater mosasaur. At around 20 feet in length, it was every bit as big as a modern crocodile. Mosasaurs aren't strictly ocean going killers anymore. These terrifying carnivores are also found in rivers!

6. Rhizodus

With a length of 20+ feet and a weight over 2 tons, Rhizodus was the size of a great white shark and had an attitude problem to match. It's huge teeth could reach over 8 inches long and would eat just about anything. This giant killer patrolled the earth around 300 million years ago.

5. Prionosuchus

Prionosuchus was probably the biggest amphibian of all time. However, it looked and behaved more like a crocodile. At up to 30 feet long, it had the size to take on anything it wanted. This giant lived some 270 million years ago.

4. Titanoboa

The biggest snake that ever lived. While snakes might not be what you expect on this list, giant constrictors today like pythons live much of their lives in water. So yeah, a 40+ foot, 1.5 ton mega-snake deserves to be on here some where. Glad this thing lived 60 million years ago.

3. Hyneria

Hyneria was one of the earliest river monsters and one of the deadliest. This 12 foot killer hunted anything it wanted, including sharks. It's also one of the most famous river monsters. Hyneria lived around 360 million years ago.

2. Spinosaurus

With a lifestyle more like a croc than a dinosaur, Spinosaurus was a river monster in it's own right. At roughly 50 feet and 7 tons, it was absolutely huge. Not only that, but it's long jaws were filled with conical teeth perfect for snapping up prey and it's giant claws were some 12 inches long. The only reason it's not number one is because the number one is even more adapted to life in the water.

1. Sarcosuchus

It was SuperCroc. Sarcosuchus attained a size of 33-40 feet and weighed in at over 5-7 tons! It was a dinosaur sized crocodile. Perfectly adapted to life in the water, taking on whatever it wanted. Sarcosuchus was possibly the biggest, baddest crocodile of all time and if there's anything we know about crocodiles, it's they're some of the greatest river monsters ever. Only this one is twice the length of any modern croc.

Hopefully I wasn't too rusty at this ;)