Mosasaurus/Segments

## MosasaurusMeuse River Lizard

* Coasts I
* Coasts IV
* Season II Opening
* Oceans I
* Oceans IV

## Presence

* Coasts (Segment 1)
	+ 1 adult
* Coasts (Segment 4)
	+ 2 adult males
* Oceans (Segment 1)
	+ 1 adult
* Oceans (Segment 4)
	+ 1 adult
* Could T. rex Really Swim?
	+ Stock footage from Coasts
* What Else Lived Alongside The Dinosaurs?
	+ Stock footage from Coasts and Oceans
* How Fast Was A Mosasaur?
	+ Stock footage from Coasts and Oceans

 Main **Segments**

MainSegments

These are Prehistoric Planet segments which feature ***Mosasaurus***.

The skull of a *Triceratops*, with the skulls of a *Mosasaurus*, *Quetzalcoatlus*, *Barbaridactylus*, and a smaller *Triceratops* skull in the background, appears in the opening of every episode of Prehistoric Planet's second season.

## Coasts

### Segment 1

* Hell Creek Formation, Montana - South Dakota, USA
* Western Interior Seaway, USA

**Coasts**, Segment I
**Setting**

* Hell Creek Formation, Montana - South Dakota, USA
* Western Interior Seaway, USA

The first segment of Coasts takes place by the southern shores of the Western Interior Seaway, an inland sea that splits North America in half, with the tracks of a dinosaur left in the sand. The creature that left the footprint is nowhere on land, however. In the sea, an adult *Tyrannosaurus* is seen swimming having smelled meat on an offshore island just a short distance from the coast, with his five young offspring following close behind. However, a mosasaur, taking notice of the tyrannosaur family, turns around in hopes of snatching one of them. The adult tyrannosaur briefly looks down in the water to gauge how close the mosasaur is, prompting him and his five children to swim faster.

***“ Turtles are normally on a mosasaur's menu. But this brood would make a welcome snack. An adult T. rex, even in water, could still defend itself very effectively. But the young must stay close. ”***

― **David Attenborough**, *Coasts*
One *T. rex* hatchling is shown unable to keep up with the rest, and. As they approach the shore, the mosasaur closing in on them, the hatchling that is lagging behind screeches more as its panic grew greater, until it got dragged down beneath the waves, the mosasaur flicking its tail and turning around just as the rest of the tyrannosaur family reached the coast of the offshore island. The patriarch of the family gets up and faces the sea, realizing that one of his five offspring was taken away. With that, he turns to the smell that drew his attention to the offshore island, a giant turtle, dead and rotting on the beach, an easy meal for him to eat.

### Segment 4

**Coasts**, Segment IV
**Setting**
Tethys Ocean, Europe
The fourth segment of Coasts takes place by the shores of southern Europe. By the submerged, coral-encrusted islands in the shallow waters, an old male *Mosasaurus hoffmannii* visits a bare rock, momentarily scaring a pycnodont fish.

***“ ... but this pycnodont fish has little to fear. This is Hoffmann's Mosasaur, the ocean's deadliest predator, but he's not here to eat, he's come to be cleaned. Mosasaurs are giant lizards, and have both a lizard's forked tongue, and, during the mating season, a lizard's colorful skin. Now, it's time to shed old skin. ”***

― **David Attenborough**, *Coasts*
Once the many inhabitants of the reef realize that the mosasaur wasn't there to eat, however, they begin to clean him, with various fish and cleaner shrimps picking off scraps from the mosasaur's teeth as well as the old skin he was shedding off, revealing that his face and back have turned a striking shade of red to make him more attractive during the mating season. The *Mosasaurus* rolls around on the rock, allowing the fishes and shrimps to clean even his belly. Since he was resting by the surface of the sea, the old *Mosasaurus* can poke his head out of the water and breathe in some air.

***“ A rival, a younger male challenging for this territory. The old male is heavier, over 15 tonnes, but his rival is more nimble. When they are as evenly matched as this, these fights can be lethal. Mosasaurs have been found with the shattered teeth of rivals embedded in their skulls. ”***

― **David Attenborough**, *Coasts*
Unfortunately, his relaxing moment at the cleaning stations is cut short when a younger male, eager to claim his territory, suddenly lunges at him, grabbing him by the neck while he's disoriented in an attempt to pin him to the rocks. Both mosasaurs retreat and circle back towards each other, barely colliding head-on, with the older male managing to halt the younger male by grazing his left side. The two pull back and collide again, with the younger male grabbing his rival's snout, trying to pin him down. As the old male struggles, the young male continues to assault him, momentarily grabbing his right front fin, but mostly attempting to crush his neck and bash him against the rocks. Momentarily fending off his rival by biting his neck and pushing him down in turn, the old male rushes up to the surface to take a breath.

***“ The old male snatches a breath. Now, he has the advantage. By dragging his rival down, he could drown him. ”***

― **David Attenborough**, *Coasts*
His strength replenished, the old male grabs his rival by the throat. When he tries to break free, the old male grabs his snout, dragging him down the walls of the submerged island, all the way down to the depths, where clouds of sand obscure both of them from view. For a moment, all is quiet. The younger male eventually emerges from the clouds, swimming to the left, with no sign of the older male anywhere. Then, at last, the old male emerges upward from the depths, triumphantly returning to the surface to breathe in once again.

***“ The old male has triumphed. For now, at least, this reef is still his territory ”***

― **David Attenborough**, *Coasts*
The segment ends with the old male leisurely keeping his head above the water as the view zooms out to reveal the great extent of the Tethys Ocean under a cloudy sky.

## Oceans

### Segment 1

* Grand Cayman Island, Central America
* Underwater Studio

**Oceans**, Segment I
**Setting**
Hakobuchi Formation, Hokkaido, Japan

**Filming Location**

* Grand Cayman Island, Central America
* Underwater Studio

***“ The ocean. The largest habitat on the Prehistoric Planet, and home to one of the biggest predators that has ever lived, a giant mosasaur. But not all mosasaurs are ferocious, 50 foot-long monsters... ”***

― **David Attenborough**, *Oceans*
The first segment of Oceans, taking place somewhere in Japan, shows a massive *Mosasaurus* swimming close to a reef, prompting several of the area's inhabitants to scamper and hide. Even so, the point of the segment was to prove that not all mosasaurs are alike. In the maze of rocks and corals, *Phosphorosaurus*, a mosasaur less than ten feet long, taking refuge in the reef to hide from her large relative, which passes by ominously outside of the crevice she is hiding in. However, when the night falls and thousands of lanternfish migrate, flashing their lights in the darkness, the *Phosphorosaurus* proves that she, too, is a fearsome predator in her own right, using her large eyes to hunt several lanternfish very effectively. By dawn, as the lanternfish shoals descend back to the depths and the massive mosasaurs come out, once again prowling the reef, *Phosphorosaurus* returns to hiding in her sanctuary amongst the coral-encrusted rocks, waiting for nightfall to hunt once more.

### Segment 4

* Grand Cayman Island, Central America
* Underwater Studio

**Oceans**, Segment IV
**Setting**
Tahora Formation, North Island, New Zealand

**Filming Location**

* Grand Cayman Island, Central America
* Underwater Studio

***“ Deep beneath the water’s surface, the world’s largest predator — the Mosasaurus — lies in wait to ambush unsuspecting prey. ”***

― The official Apple TV+ episode synopsis for *Oceans*
The fourth segment of Oceans takes place in the heart of the Pacific Ocean, where lagoons within atolls serve as the only sanctuary for thousands of miles. In these safe areas, several *Tuarangisaurus* take refuge. However, every day, the elasmosaurs need to hunt, and to do so, they must leave their shallow shelter and venture into the deeper waters of the open ocean. There, where nutrients rise from the ocean floor, thousands of fish gather, ensuring a plentiful supply of food for the elasmosaurs. In turn, however, they themselves become part of the menu of the rich feeding grounds.

***“ Streamlined bodies and four powerful flippers give elasmosaurs great maneuverability. But their daily feeding forays make their movements predictable for an intelligent and patient hunter. Mosasaurus is an ambush predator. This enormous animal uses its huge tail to accelerate with astonishing speed. ”***

― **David Attenborough**, *Oceans*
A fifty-foot *Mosasaurus*, the biggest predator in the Late Cretaceous oceans, stalks them from the ocean floor, having predicted their movements due to their daily feeding forays. In one sudden movement, the mosasaur rushes upward and almost catches an elasmosaur, which manages to escape. Unlucky in catching prey, the *Mosasaurus* retreats back to the ocean floor. With many elasmosaurs around, it didn't take long before another opportunity presented itself. Camouflaged against the ocean floor, the *Mosasaurus* awaits for an easy target, and rushes at it from below, emerging out of the water with the elasmosaur in its massive jaws.

***“ Mosasaurus can strike their prey with such force that the impact alone can kill. It's an attack so swift, the elasmosaur almost certainly never saw it coming. ”***

― **David Attenborough**, *Oceans*
The *Mosasaurus* circles around the *Tuarangisaurus*, which was instantly killed by its assault, floating just beneath the surface of the water. With the hunt over, the mosasaur grabs its prey and drags it to the bottom for it to feed on.

## Prehistoric Planet: Uncovered - Could T. rex Really Swim?

  **Could *T. rex* Really Swim?**
**Subject**
The evidence supporting the idea of *T. rex* being capable of swimming, much like other large animals in the modern day.

**Experts**
Dr. Darren Naish
***“ But 66 million years ago, venturing into coastal waters would not have been without risk, even for T. rex. Mosasaurs hunted beneath these waves, and young tyrannosaurs, particularly, would have been a valuable meal for these formidable aquatic hunters. T. rex may have been strong swimmers, but they could only have been brief visitors to the prehistoric oceans. Although their name means 'Tyrant Lizard King', they could never have ruled the waves while the mosasaurs patrolled the coasts. ”***

― **David Attenborough**, *Prehistoric Planet: Uncovered - Could T. rex Really Swim?*
Footage of *Mosasaurus* stalking the *Tyrannosaurus* family in the first segment of Coasts was shown at the end of this Uncovered segment. Although the segment established that *T. rexes* could swim, that capability is not sufficient to guarantee their safety in the water, with them being nothing more but vulnerable visitors in the domain of the mosasaurs, the true rulers of the waves from the open seas to the coasts.

## Prehistoric Planet: Uncovered - What Else Lived Alongside The Dinosaurs?

  **What Else Lived Alongside The Dinosaurs?**
**Subject**
The other weird and wonderful creatures that lived alongside the dinosaurs, from *Beelzebufo*, marine reptiles, and pterosaurs, to their successors, mammals.

**Experts**
Dr. Darren Naish, Dr. Marc Jones, Dr. Mark Witton, Professor Anjali Goswami
***“ The oceans were dominated not by dinosaurs, but by marine reptiles. The largest were mosasaurs. These giant marine lizards could reach 50 feet in length, and weigh 15 tonnes. ”***

― **David Attenborough**, *Prehistoric Planet: Uncovered - What Else Lived Alongside The Dinosaurs?*
In this Uncovered segment, which goes over the many animals that lived alongside the dinosaurs, the marine reptiles are brought up as masters of the sea, following the part dedicated to *Beelzebufo*. While footage of *Tuarangisaurus* from the sixth segment of Coasts and the fourth segment of Oceans was first shown, it was followed by *Mosasaurus* emerging victorious from its fight in the fourth segment of Coasts, then its fatal assault on a *Tuarangisaurus* in the fourth segment of Oceans. With their great size, elongate, powerful jaws with huge muscles, and enormous conical teeth, mosasaurs are stated to be "the greatest marine predators of all time". Following this, the dominance of pterosaurs over the skies was discussed.

## Prehistoric Planet: Uncovered - How Fast Was A Mosasaur?

  **How Fast Was A Mosasaur?**
**Subject**
The speed and acceleration of mosasaurs, as well as the means which allow them to perform the feats that make them quick, formidable, and powerful ambush predators.

**Experts**
Dr. Michael Habib, Kiersten Formoso
Footage of *Mosasaurus* from Coasts and Oceans, along with a brief moment of *Kaikaifilu*, are shown in this Uncovered segment, which is dedicated to discussing how fast a mosasaur could be.

***“ Mosasaurs were seagoing lizards. Think of a giant, swimming, whale-sized Komodo Dragon. Tapered snout, rough skin, four fins instead of normal limbs, and a long tail that would look a lot like a shark tail, but upside down. That's basically a mosasaur. ”***

― **Dr. Michael Habib**, *University of California*
Presented as the main focus is the largest mosasaur, *Mosasaurus hoffmannii*. The secret to the success of this ambush hunter is that it can move with incredible speed while it was only stationary moments before. Today, this is demonstrated by crocodiles, which have muscles that can deliver short bursts of tremendous power. Dr. Michael Habib, one of the show's consultants, brings up how mosasaurs may have bent themselves in a C-shape, then, in one sudden movement, push off of the water on the side of their bodies. As seen in modern-day fish, this "C-start" technique allows them to accelerate from a standstill to full speed in an instant. The suggestion is that mosasaurs use this same technique on a much greater scale. Using a 42-foot, 12-ton mosasaur for reference, the Prehistoric Planet research team ran a unique test four times to finally figure out exactly how fast can *Mosasaurus hoffmannii* actually swim.

***“ This mosasaur could probably clear 75% of its body length in one single second. That means if that mosasaur is 17 meters away from you, in one second, it will be 75% closer, and in the 2nd second, it would have surpassed you and probably eaten you along the way. ”***

― **Kiersten Formoso**, *University of Southern California*
The force generated by a mosasaur traveling at full speed is compared to the impact of a full-sized semi-truck, which, along with the mosasaur's powerful bite force, can prove immediately fatal.

***“ Mosasaurs could reach 30 miles an hour in as little as one second. This is what makes them arguably the ultimate marine predator of all time. ”***

― **David Attenborough**, *Prehistoric Planet: Uncovered - How Fast Was A Mosasaur?*
With this, based off of these calculations, a mosasaur 13 meters (42 feet) in length like the one in the diagram displayed in this segment could travel 9.75 meters (32 feet) per second, and a mosasaur that is 15 meters (50 feet) long like the one on the show could travel 11.4 meters (37 feet) per second.

## Trivia

### Coasts

#### Segment I

* There is no confirmation that the mosasaur in the segment is *Mosasaurus* itself. However, the model used is identical, and a mosasaurine measuring at least 11 meters (36 feet) long was found in the Hell Creek Formation. It is possible that these remains belong to a sub-adult *Mosasaurus*, given its status as a cosmopolitan species (being found on all seven continents).

#### Segment IV

* As confirmed by Dr. Darren Naish, lead consultant of Prehistoric Planet, the *Mosasaurus hoffmannii* in the fourth segment of Coasts is officially nicknamed "Hoff".
* This is the first segment to feature intraspecific combat, and also the first one to result in the older individual winning.

### Oceans

#### Segment I

* It is possible that the large mosasaur depicted in the first segment of Oceans is *Mosasaurus hobetsuensis* of the Hakobuchi Formation in Hokkaido, Japan, though, given its dubious validity, it is possible that it is also *Mosasaurus hoffmannii*.

## References

### General

1. ↑ The first in situ collection of a mosasaurine from the marine Breien Member of the Hell Creek Formation in south-central North Dakota, USA

### Dr. Darren Naish

1. ↑ The big male *Mosasaurus hoffmannii* in the fourth segment of Coasts is nicknamed "Hoff".

### Prehistoric Planet

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 I Know Dino: The Big Dinosaur Podcast, Episode 446: Dinosaur-era Oceans and Darren Naish from Prehistoric Planet 2