North America

* Title
* I
* II
* III
* IV
* V

***“ Not many can intimidate North America's top predator, Tyrannosaurus rex, whose size and bite are a deadly combo, except for a giant winged foe. ”***

― The official Apple TV+ episode synopsis for *North America*
***North America*** is the fifth and final episode of the second season of Prehistoric Planet, and the tenth episode of the series overall.

## Segment I: The Javelina Shoreline

**North America**, Segment I
**Setting**
Javelina Formation, Texas, USA

**Filming Location**
Wharariki Beach, Cape Farewell, South Island, New Zealand

***“ The coast of the vast, inland sea that almost splits North America in half. Here in the south, as the tide falls, giants are drawn to the shoreline. These Alamosaurs are a hundred feet long, and weigh some 80 tonnes. They are the largest dinosaurs on the continent. So huge that no predator can tackle them. ”***

― **David Attenborough**, *North America*
In the first segment of the episode, by the shores of the Western Interior Seaway, a herd of *Alamosaurus* travel along a beach. Given their great size, the titanosaurs are able to travel without fear of harm from any predator.

***“ Some live to a great age. This male is around 70 years old. Many in the herd are likely to be his offspring. But his long life is now coming to an end. His immense body is beginning to fail him. He may not survive the night. ”***

― **David Attenborough**, *North America*
As they go around a bend in the path, one 70 year-old male, feeling that his time is up, slowly drops down on the beach, the rest of the herd moving on without him. Accepting that his long life is at its end, the old male lays his head on the sand, closes his eyes, and peacefully passes away.

***“ Dawn. And these troodontids have picked up a scent. They're quick to investigate anything new, especially if it might be worth eating. But biting through a three inch-thick hide is beyond their power. Very frustrating. ”***

― **David Attenborough**, *North America*
The next day, a trio of troodontids visit the beach, having smelled the corpse of the recently-deceased titanosaur. Skittishly, they explore and climb atop the dead sauropod, looking for the best part to start their meal. To their frustration, however, the small theropods found themselves unable to bite through the titanosaur's hide, which is three inches thick.

***“ Tyrannosaurus rex. North America's top predator. With his six inch-long teeth, tearing through an Alamosaur's tough skin is not a problem. ”***

― **David Attenborough**, *North America*
As they continued to attempt to take bites out of the corpse, the troodontids are then scared away by a male *Tyrannosaurus*, which is easily able to feed on the carcass with his six-inch teeth and bone-crushing bite. One troodontid manages to take one strip of meat as the *T. rex* feeds before being forced away again.

***“ T. rex might be able to bully troodontids, but a carcass as big as this soon attracts more formidable competition... ”***

― **David Attenborough**, *North America*
The smell of the massive carcass, extremely visible on the open beach, soon attracts the attention of other carnivores. As he is eating his meal, the *T. rex* soon hears a series of booming calls from above, and turns towards the source of the noise, growling in frustration upon realizing that he can no longer eat the carcass undisturbed.

***“ Quetzalcoatlus, a giant pterosaur. One of the few creatures that will challenge an adult tyrannosaur. One strike from its six foot-long beak could easily cost T. rex an eye. Even so, it seems that he's not going to back down. ”***

― **David Attenborough**, *North America*
A *Quetzalcoatlus* lands down on the beach, eyeing the dead titanosaur right in front of it. The *T. rex* roars at the *Quetzalcoatlus* in an attempt to scare it off, but the azhdarchid pays no heed to the theropod's warnings as it slowly marches towards the carcass. The *T. rex* turns to face the pterosaur, revealing that his right eye is milky, with a horizontal scar across the eyeball, implied by the narration to have been rendered blind by a prior *Quetzalcoatlus* attack. As the *T. rex* continued to growl at it, the azhdarchid paused its advance to test the extent of the *T. rex's* aggression. Believing that his taller, lankier rival would not attempt to challenge him further than it already has, the *T. rex* turns back to his meal, prompting the *Quetzalcoatlus* to try and walk towards the carcass again.

***“ But the arrival of a second Quetzalcoatlus changes the odds. After all, two beaks are deadlier than one. ”***

― **David Attenborough**, *North America*
No sooner did the theropod return to eating than another bellow echoed from the skies. Both the *T. rex* and the *Quetzalcoatlus* paused to turn their attention to the new arrival. A second *Quetzalcoatlus* has landed on the beach, and together, the two pterosaurs boldly close in on the *T. rex*.

Both *Quetzalcoatlus* charge in, snapping their beaks to make clear their defiance, but quickly dart away as the aggravated *T. rex* rushed towards them. Their intent is not to take on their heavier and more powerful adversary head-on, however. Instead, they plan to repeatedly harass and even injure him until they had inflicted enough discomfort to convince him to leave. While one *Quetzalcoatlus* gets chased off by the *T. rex*, the other lands atop the *Alamosaurus* corpse, diverting the *T. rex's* attention and enraging him even further.

As this azhdarchid gets into a squabbling match with the *T. rex*, having the annoyed theropod's undivided attention, the other *Quetzalcoatlus* flies at the *T. rex* from behind, almost pecking him in the back as it passed overhead. With the *T. rex* distracted yet again, the other *Quetzalcoatlus* leaps off the dead *Alamosaurus* to take part in the aerial harassment. Again and again, the two *Quetzalcoatlus* strike the *T. rex* in the back with their long beaks as he tried to swing around and grab one of them.

***“ For T. rex, this is now too dangerous. Some fights just aren't worth the risk. For now, the flying giants have won. They quickly eat all they can. But T. rex will almost certainly be back to claim his share once his flying rivals leave. ”***

― **David Attenborough**, *North America*
Overwhelmed by the assault, the *T. rex*, unwilling to risk receiving potentially more grievous injuries, abandons the titanosaur corpse to the azhdarchids, whom promptly feast on the bountiful meal. Given how the *Quetzalcoatlus* pair are unlikely to strip a considerable amount of the massive carcass clean, the *T. rex* will almost certainly return to feast on what's left once the pterosaurs have had their fill and moved on.

## Segment II: *Globidens* and *Sphenodiscus*

**North America**, Segment II
**Setting**
Gulf of Mexico, Western Interior Seaway, USA
***“ In the waters that surround North America, there are other giant predators. But they have no rivals. Mosasaurs. They may look like huge sharks, but they are in fact, a kind of aquatic lizard. Size, speed, and powerful jaws mean that very few creatures in the ocean are safe from these hunters. In the Gulf of Mexico, this Globidens mosasaur is searching for one particular kind of prey. ”***

― **David Attenborough**, *North America*
In the second segment of the episode, in the Gulf of Mexico, a *Globidens* swims through the open seas, seeking out shoals of its favorite prey, "tiger ammonites".

***“ Tiger ammonites, Sphenodiscus. Every year, huge shoals of females come up from deep water, and travel towards the coast. They have all recently mated, and each is now carrying hundreds of fertilized eggs. The eggs must be laid in the shallows... and that is where the mosasaur is waiting. ”***

― **David Attenborough**, *North America*
Every year, from the deep levels of the ocean, thousands of female *Sphenodiscus* come up to the coast, each ammonite carrying hundreds of fertilized eggs that need to be laid in the shallows, right where *Globidens* is waiting for them, using its forked tongue to hone in on their location.

***“ Tiger ammonites are themselves hunters. The combination of a streamlined profile and a powerful siphon enables them to shoot through water at great speed. But so can the mosasaur. ”***

― **David Attenborough**, *North America*
The *Sphenodiscus* use their own predatory traits (their streamlined profile and powerful siphon) to get to their destination faster and evade incoming threats. Unfortunately for them, *Globidens* is also quick enough to catch up to them and attack.

***“ Globidens has broad, rounded teeth that easily crack the ammonite's shell, releasing the air that keeps them buoyant. Without it, they sink helplessly to the seabed. Before the ammonites can escape, the mosasaur disables as many as it can. ”***

― **David Attenborough**, *North America*
With its globular teeth, the mosasaur easily crunches through the shells of the ammonites, releasing the buoyant air within its prey, disabling and sinking as many *Sphenodiscus* as it can instead of taking time to consume each ammonite it catches. Once the shoals of ammonites have passed through the area, with no more prey to cripple, *Globidens* feeds on the ammonites it sunk to the ocean floor, cracking the dead with its open teeth before ripping out their soft bodies from their shells.

***“ Finally, time to tuck in. Globidens may have killed dozens... but even this makes only a small impact on the overall numbers of ammonites. Most of the shoal have survived, and continue on their journey to their spawning grounds. The rocky seabed here has many cracks and crevices, ideal places for attaching the ammonites' precious egg sacs. The females then abandon them. But safe in this coastal nursery, these eggs will produce the next generation. These coastal seas are full of life... ”***

― **David Attenborough**, *North America*
Despite the mosasaur having killed dozens of the ammonites, hundreds more make it to the shallows to successfully lay their eggs. The females deposit their egg sacs in the many rocky crevices in the seabed, and leave them. Safe in the coastal nursery, the eggs will spawn the next generation of ammonites to continue the cycle.

## Segment III: *Pectinodon* and "Styginetta"

**North America**, Segment III
**Setting**
Denver Formation, Colorado, USA

**Filming Location**
Mono Lake, Mono County, California
***“ ... yet on land, and only a few hundred miles away, there is desolation. Here, powerful movements deep in the Earth's crust are beginning to raise the Rocky Mountains. The immense changes in the landscape have cut off this lake from nearby rivers. Its waters evaporate in the strong winds and intense summer sun, and the minerals that have dissolved in it are beginning to reach toxic levels. For most, this water is simply too poisonous too drink. Even so, every year, this place is visited by all kinds of animals. ”***

― **David Attenborough**, *North America*
In the third segment of the episode, many animals are shown visiting an evaporating toxic lake for feeding opportunities. Among them, "Styginetta", a primitive relative of ducks, and a family of dinosaurs. Six juvenile *Pectinodons* poke out from the rocks, lead to the toxic lake by their father.

***“ These dinosaurs and the Styginetta are both drawn here by a strange seasonal bonanza. Flies. The larvae of these insects are able to filter out the lake's toxic salts, and, as a consequence, they thrive in immense numbers. Now, they're hatching into adults in their millions. They are a rich and abundant source of protein for all the lake's visitors. Pectinodon are particularly intelligent dinosaurs. It doesn't take them long to work out the best way to collect flies. ”***

― **David Attenborough**, *North America*
Watching millions of flies and emerging from the lake, the juvenile *Pectinodons* jump up and snap at the flies, but they soon eventually figure out that the best way to scoop up as many flies as possible is by rushing at them, stirring the flies like dirt from the ground, with their jaws gaping open to collect them in mouthfuls. A flock of "Styginetta" watch as the juveniles run around gulping flies, which eventually ends up with two of the juveniles crossing each other's paths while rushing, causing them to collide and get knocked to the ground.

***“ But their father has his eyes on a bigger prize. Pectinodon are not only intelligent, they're also very skillful hunters. ”***

― **David Attenborough**, *North America*
While all this is happening, however, the father of the *Pectinodon* chicks closes in on one "Styginetta" flock from behind, slowly approaching the birds while staying low, obscured by the rock and mineral pillars around the lake. By the time the birds realize he is there, the flock taking to the air, the *Pectinodon* leaps up and catches one by the throat in midair, swinging and slamming his prey twice to the ground before finishing off the bird with another bite.

***“ Success. A rather more substantial meal for the family, and just as well. The flies will only be here for so long, and the dinosaur family will be forced to find food elsewhere. ”***

― **David Attenborough**, *North America*
As the "Styginetta" fly off, with many other flocks of them still ankle-deep in the lake, looking for flies to eat, the *Pectinodon* father brings his catch to his six chicks, the family settling down to eat as flocks of "Styginetta" fly overhead.

## Segment IV: *Triceratops* Gathering

**North America**, Segment IV
**Setting**
Lance Formation, Wyoming, USA

**Filming Location**
Winterfold Forest, western Greensand Ridge, Surrey, England

***“ Further north, the Rocky Mountains are still slowly rising. And as they do, they create higher, cooler landscapes where vast pine forests flourish. As spring arrives, strange calls echo through the trees. The mating season has arrived for one of North America's most heavily-armed dinosaurs. Triceratops. Every year, large numbers of these giants gather in clearings. The females have come to choose a mate. The six-tonne males fight and display their strength. ”***

― **David Attenborough**, *North America*
In the fourth segment of North America, in the pine forests further up north by the Rocky Mountains, strange calls echo. Within a clearing, a large number of *Triceratops* gather, with females looking for mates, and males fighting to prove which one of them is the better candidate.

***“ This young male looks to be in prime condition, showing off his meter-long horns and his colorful head frill. His horns appear perfect, not yet damaged by battle. To a female, however, the absence of any wear and tear might suggest a potentially-critical weakness; a lack of experience. ”***

― **David Attenborough**, *North America*
One of the young, six-tonne males attempts to impress some females by showing off his colorful frill and meter-long horns, perfectly-shaped and undamaged. Ironically, for the females, this makes the male a subpar choice, for the lack of wear and tear shows that the male is inexperienced, not seasoned by battle.

***“ These gatherings are crucial events in the lives of Triceratops. They provide the best chance in the whole year for the adults to become parents. And young hopefuls are not the only ones here. A 30 year-old male, weighing more than 10 tonnes. If there's one thing that he has in spades, it's decades of wear and tear. He may be old, but he's still strong enough to challenge a young rival, however fit. The stakes are high, and neither is willing to back down. ”***

― **David Attenborough**, *North America*
Just then, a 30 year-old male, weighing over ten metric tons, walks in, his experience clear in his massive physique and impressively-long horns, with his right one longer than his left. Challenging each other to a duel, the younger male with the perfect horns and the veteran clash, locking horns repeatedly.

***“ The veteran has a four-tonne weight advantage... and the skill to make it count. ”***

― **David Attenborough**, *North America*
Even so, it is clear that, in the struggle, the veteran has full control of the battle, using his greater mass to push the younger male back, while the younger male is unable to hold off the veteran. As they continue to lock horns, the veteran uses the skill he mastered through decades of experience to lift his rival up by the face and throw him to the ground.

***“ The youngster's horns are no longer perfect. The old bull's fighting prowess certainly seems to have impressed this female. ”***

― **David Attenborough**, *North America*
When the dust settled, the younger male stood back up, the tip of his right horn snapped off and on the ground, along with his aspirations of getting a mate. The veteran proceeds to drive him off before attracting and mating with a female that witnessed the fight. The young male, with his horns no longer perfect, walks away, his chances for that year's mating season gone. Even so, there is the hope that, with this damage, he can attract a female next mating season, for he now has proof of having faced battle, regardless of whether it went his way or not.

***“ For the loser, the mating season is over. However, his newly-won battle scars may be just enough to attract a female next time the herds gather here to mate. ”***

― **David Attenborough**, *North America*
It is even possible that, when he grows older and his left horn has healed, he'll end up being just like his opponent, a grizzled, ten-tonne veteran with longer horns, the right one longer than the left, a sign of great experience.

## Segment V: *Nanuqsaurus* and *Ornithomimus*

**North America**, Segment V
**Setting**
Prince Creek Formation, Alaska, USA

**Filming Location**
Meagher County, Montana, USA

***“ Here, within the Arctic Circle, for three months of the year, the sun barely rises. When its warmth finally returns after the long winter, feathered Ornithomimus are quick to take advantage. These fleet-footed travelers are among the fastest runners of all dinosaurs, capable of covering vast distances in search of fresh vegetation. They're so fast, they're very difficult for predators to catch. ”***

― **David Attenborough**, *North America*
In the fifth and final segment of North America, following three months of cold winter darkness, the sun finally rises and warms up the Arctic Circle. A flock of nine *Ornithomimus* rush out, using their great speed to cover vast distances and find fresh vegetation, eventually finding what they sought for in a thawing field of snow.

***“ After a tough winter, this female Nanuqsaur needs to make a kill soon. A smaller relative of T. rex, but more agile, and, critically faster. There is nowhere to hide, so a surprise attack is impossible. Instead, she resorts to creating panic. ”***

― **David Attenborough**, *North America*
A short distance behind them, a female *Nanuqsaurus* eyes them hungrily. With nowhere to hide and therefore no opportunity to ambush, the *Nanuqsaurus* decides to just outright rush at the flock and hope one blunders due to panic. The flock splits into two, four moving to the right as the other five rush left, the *Nanuqsaurus* choosing to continue chasing the latter group. Eventually, the *Nanuqsaurus*, out of energy, halts its pursuit, growling in frustration as the *Ornithomimus* dash further away.

***“ Each failed hunt uses up more precious energy, bringing her ever closer to starvation. ”***

― **David Attenborough**, *North America*
Although it was spring, the Arctic Circle was still subject to freezing winds and fluctuating temperatures. A flock of seven *Ornithomimus* are out grazing on a rocky slope full of vegetation, and this time, the *Nanuqsaurus* takes advantage of the flurries of snow and the rocks around her to close the distance between her and the flock without being seen. Slowly, she inches forward, and charges at the flock once she was close enough. Screeching, the seven *Ornithomimus* rush down the slope, the tyrannosaur just a few feet behind them. Two *Ornithomimus* split off to the right, and the *Nanuqsaurus* goes after the larger group of five which ran left.

One *Ornithomimus* in the back slightly stumbles on the ground, getting left behind by the others, and, realizing that it is now the main target of the predator, circles back and runs left, back up the slope, almost getting caught by the *Nanuqsaurus* in the process. The pursuit continues up the mountain until eventually, the *Ornithomimus* makes a critical error and slips on the snowy terrain. Just before it could fully get back up, the *Nanuqsaurus* finally grabs it by the throat, dragging it around before crushing its neck with her jaws. Checking to see if her prey is really dead, the *Nanuqsaurus* picks up the freshly-slain *Ornithomimus* by the neck and makes a slow trip back up the mountain, where her seven hatchlings are waiting.

***“ If her babies are to thrive, she will have to repeat today's success over and over again, until her young are old enough to join her in the hunt, and, eventually fend for themselves, here in this remote - and perhaps the most challenging - frontier of the North American continent, 66 million years ago. ”***

― **David Attenborough**, *North America*
As the family feeds on what may be their first meal in many weeks, three *Ornithomimus* feeding on vegetation watch the scene from a distance, likely fearful that they may be next. Noticing them, the *Nanuqsaurus* gets up and turns to face the *Ornithomimuses* with a huff, causing them to scamper back down the slope. Turning back to her family, she tends to her hatchlings as they chirp up at her before continuing to eat the meal with them.

## Uncovered Segment I: How Did Dinosaurs Get So Big?

  **How Did Dinosaurs Get So Big?**
**Subject**
The evolutionary means and efficient systems that let sauropods attain their massive sizes.

**Experts**
Professor Paul Barrett, Dr. Susannah Maidment
TBA

## Uncovered Segment II: Why Did *Triceratops* Have A Frill?

  **Why Did *Triceratops* Have A Frill?**
**Subject**
The overall function of *Triceratops* frills as display features and defensive weapons.

**Experts**
Professor Paul Barrett, Dr. Susannah Maidment

This Uncovered segment, using footage of *Triceratops* from Forests and North America, is dedicated to uncovering the reason behind why the ceratopsian developed the head frill. Even 140 years after the first fossil was found, the purpose of the massive frill is still being investigated.

***“ These were enormous structures, so it's an enormous investment in bone and in tissue, and also in the muscular effort to hold these structures up. All of this investment must mean that these features are very important to the animal's way of life. ”***

― **Professor Paul Barrett**, *Natural History Museum*
Injuries on the fossils, like lesions on the skull and bite marks left by predators on the frill appear to indicate that they were meant for defense. But there's also the possibility that they were display structures to help attract mates. In living animals like moose, huge structures like horns and antlers serve as an attractive display and an indication of great health, which in turn helps the females know which male is ideal to mate with in order to produce the best of young.

***“ If it was only for defense, then we would expect to see them develop to the same degree in juveniles as in adults, but we don't. We see them being much smaller in the juveniles and not really developing into the very, very large structures of the adults until much later. ”***

― **Dr. Susannah Maidment**, *Natural History Museum*
Additional proof of their use in sexual display is seen in the very heavily-grooved surfaces of the frills, which were probably meant to house nerves and blood vessels to supply the skin growing over the frills, with these large surface areas likely being brightly colored to show off to potential mates. As a structure that serves many purposes, from attacking and defending against predators and rival males to serving as a vibrant display to attract females, the frill of *Triceratops* would have been an "awe-inspiring sight, to friend or foe".

## Fauna

*Alamosaurus sanjuanensis**Pectinodon bakkeri**Tyrannosaurus rex**Quetzalcoatlus northropi**Globidens alabamaensis**Sphenodiscus sp.*"Styginetta longfreni"*Triceratops horridus**Ornithomimus edmontonicus**Nanuqsaurus hoglundi*
## Trivia

The first segment of the episode took 600 days to animate.

## References

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 I Know Dino: The Big Dinosaur Podcast, Episode 447: Dinosaurs in North America: Featuring Prehistoric Planet 2