So far, the gang have dived in one of the 7 deadliest seas of all time. And from here on it's only going to get worse, ahead lies some of the deadliest sea reptiles, and the most lethal shark the world has ever seen.

But now, only they can escape the Devonian seas, and an armored fish, called Dunkleosteus.

5th Most Dangerous Sea Of All Time

Name: The Devonian

When: 360 million years ago

Hazards: Dunkleosteus

The group of 8 have exited the time warp and landed in the seas of the Devonian, and as they swam to the surface luckily their was more Oxygen then last time. Luckily Twilight has magically made a large boat appear and they climb on.

Good thinking Twilight. Applejack said.

Well, Now that we're out of the water. Rarity said. Where are we now?

Look, I wish I knew but I don't. She answered.

Aw, don't worry Twilight I'm sure we'll be home soon. Spike said.

Anypony up for a swim? Pinkie asked.

I think I'm just about done swimming for one day. Rainbow said.

I know. Twilight said.

She magically made a underwater camera appear.

What's that for? Starlight asked.

It's to look around in the water. Said Twilight.

She place the camera in the water and it took off swimming to explore the Devonian sea.

An hour later the camera came back and they went inside, and Twilight made a screen appear as they watched as what the camera. Then a object appears and it's a giant fish.

Whoa, what is that? Rainbow asked.

I'm not sure. Twilight said.

The girls and Spike were looking at the top predator of Devonian ocean, Dunkleosteus. This monster grew over 30 feet long and weigh as much as a African Elephant, It was like real leviathan. But if that didn't stun them this did, the screen showed a close up view of It's head. And there's armor plating on the head maybe 2 inches thick.

That is one fearsome head. Applejack said.

Man, look at those teeth! Rainbow said.

But what she didn't know is that they weren't teeth at all. They are parts of the jaws, and they were perfect for chomping through other armored fish of this time. And those jaws are pack with muscle in the skull giving them some of the strongest jaws ever. And soon they are about to find out just how strong they are.

Minutes later Rainbow has made a bet with Twilight that the jaws of Dunkleosteus can bite through anything, and Twilight has agreed and the test subject is chain mail. But they needed some bait. As they fish, the others were building a cage for their protection for whoever goes down there. They built it round that way the Dunkleosteus will slips it's jaws from the bars, similar to a dog trying to grip a beach ball with it's mouth.

Soon Twilight has pulled in a species of placoderm called Bothriolepis it's in the same family as Dunkleosteus but many times smaller. And minutes later the bait was covered in chain mail and soon the 2 have swam into the cage. Before a familiar image has appeared, a shark but this one has a weird shape of it's dorsal fin. It's much like an ironing board, this species is called Stethacanthus. the shark swims around for a minute but then it swims off like it was scared by something.

Twilight and Rainbow looked around for a minute, but then a Dunkleosteus appears from the gloom. The two ponies were dwarfed by this sea monster, much bigger than a Great White Shark or even a Killer Whale. The giant predatory fish circles the cage for few minutes, before Twilight finally manages to get her nerves together sticks the bait out. And the Dunkleosteus begins to get interested, and this was beginning to be no fishermen's tale and they were dealing with a real monster. Then the fish comes in again, but fast this time but luckily he only puts a dent in the bars. he is really wanting that bait, thinking that he is wild up enough Twilight sticks the bait out and within seconds the predator took the bait from her. Within a second the sea monster bit through the armored fish and chain mail like it was nothing.

And it appears Rainbow has won her bet, a piece of the fish sank to the seabed. Moments later a juvenile Dunkleosteus appears and feeds on whats left. But suddenly the Dunkleosteus from earlier has swam out of nowhere and caught the little fish. The 2 friend were shocked by the seen as the adult eats the youngster, and they were glad that Fluttershy was not here to see this.

The Dunkleosteus was certainly showing it's true form. It's not just a predator, but a cannibal as well. And as for it's table manners.

Then the Dunkleosteus regurgitated the armor and bits of chain mail. Twilight has red this before in other fish, it's normal behavior it's getting rid of the undigestible pieces, and it's perfectly normal.

Normal for 360 million years ago, maybe.

Once the Dunkleosteus was gone Twilight and Rainbow swam back up to the boat.

Well, what happen? Starlight asked.

I won the bet! Rainbow said. That's what happen.

And let's just there was one part that Fluttershy was glad she didn't came down with us. Twilight said.

But there's no time to rest on laurels. They've yet to reach the halfway mark of their voyage in prehistory. And ahead of them are 5 more ever deadlier encounters in the sea.

Next time the group witness their Amphibian ancestors as they take their first step as they move on to dry land. And escape their new enemy... The Fish.

Fun Fact from last chapter: Pterygotus sadly lost It's record as biggest arthropod ever when Jaekelopterus was found.