Quetzalcoatlus

## QuetzalcoatlusPrecious/Feathered Serpent

* **Beak Length** of 1.8 meters (6 feet)
* **Skull Length** of 3 meters (10 feet)
* **Flight Ceiling** of 4.6 kilometers (2.86 miles)
* **Flight Speed** of 130 kilometers (80 miles) per hour
* **Flight Range** of 13,000 - 19,000 kilometers (8,000 - 12,000 miles) in 7 - 10 days

 **Main** Segments

MainSegments

***“ Southern Africa. Here, too, the annual rains create floods. And the land turns into a maze of narrow channels running between countless small islands. This is now a swamp forest. And it attracts one of the largest flying animals that has ever lived on Planet Earth. A giant pterosaur, Quetzalcoatlus. This is a female, her wings are over 30 feet across. And she's come here for one particular reason... ”***

― **David Attenborough**, *Freshwater*
***Quetzalcoatlus*** (named after the Aztec feathered serpent god, "Quetzalcoatl", which means "Precious Serpent" or "Feathered Serpent") is a genus of azhdarchid pterosaur that lived in the Javelina Formation of Texas and the Ojo Alamo Formation of New Mexico, USA, 68 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period. An azhdarchid neck vertebra found in Hell Creek may also indicate the presence of *Quetzalcoatlus* in Montana and South Dakota.

## Paleobiology

### Size and Physique

***“ Quetzalcoatlus are certainly masters of flight, but they're also, perhaps surprisingly, very competent on the ground. Each wing is supported by the single greatly-elongated bone of her fourth finger. By turning her wings upwards, she can walk very effectively on all-fours. ”***

― **David Attenborough**, *Freshwater*
At 5.5 meters (18 feet) tall, *Quetzalcoatlus northropi* was as tall as a giraffe, with an impressive wingspan of 10 - 11 meters (36 feet), yet, thanks to powerful tendons, hollow bones, and an overall lightweight build, it is able to fly. Early estimates give weights as low as 70 kilograms (150 pounds), though most estimates after the year 2000 set a weight of 200 - 250 kilograms (441 - 550 pounds) for *Quetzalcoatlus northropi*, as per the recent studies of Dr. Mark Witton and Dr. Michael Habib, two of the experts who worked on Prehistoric Planet. The earlier, lower weights are more fitting for the smaller, more recently-discovered species, *Quetzalcoatlus lawsoni*, which was found to be half the size of *Quetzalcoatlus northropi*. Dr. Darren Naish, lead consultant of Prehistoric Planet (who also has extensive experience in the field of pterosaur research), places the weight of *Quetzalcoatlus northropi* at around 220 kilograms (485 pounds).

The head of *Quetzalcoatlus* is slender and spear-like, stated to be up to three meters (10 feet) long, including a beak that is 1.8 meters (6 feet) long.

### Sounds

Much like its relative, *Hatzegopteryx*, *Quetzalcoatlus* is depicted on the show communicating by means of deep, airy, booming sounds much like moose bellows, considered a more logical voice for the pterosaurs rather than stereotypical shrieks and screams. Its bellows are not as deep as those of *Hatzegopteryx*, however, given its slimmer, less-robust physique.

### Prehistoric Planet's Depiction

*Main: *Quetzalcoatlus* on Prehistoric Planet*

Main: *Quetzalcoatlus* on Prehistoric Planet

On Prehistoric Planet, the females are covered in a tan and bluish-gray pycnofiber coat, and they also sport a small, rectangular crest on top of their head. Two similar-looking individuals were also seen in North America, though it is unknown if they are meant to be females, or if at least one of the individuals from North America is male, implying that, unlike *Hatzegopteryx*, *Barbaridactylus*, and *Tethydraco*, Prehistoric Planet does not depict *Quetzalcoatlus* as a sexually dimorphic pterosaur species.

The skull of a *Triceratops*, with the skulls of a *Quetzalcoatlus*, *Mosasaurus*, *Barbaridactylus*, and a smaller *Triceratops* skull in the background, appears in the opening of every episode of Prehistoric Planet's second season. *Quetzalcoatlus* is the focus of the fourth segment of Freshwater, where a female lays her eggs in the swamp forests of South Africa and ends up getting into conflict with another female that attacked her nest while she was away. *Quetzalcoatlus* also appears in the first segment of North America, where a pair of them harass a *T. rex* to force it away from an *Alamosaurus* carcass they want to scavenge, with footage of their conflict with *T. rex* being used in the Prehistoric Planet: Uncovered segment "What Else Lived Alongside The Dinosaurs?", during the part where the pterosaurs' dominance of the skies is discussed. Finally, *Quetzalcoatlus*, along with fellow azhdarchid *Hatzegopteryx*, serves as the main focus of the Prehistoric Planet: Uncovered segment "Could Giant Pterosaurs Really Hunt on the Ground?", which discusses the hunting preferences of azhdarchids and, based on evidence, concludes that they were well-suited for stalking and even pursuing prey on the ground.

## Paleoecology

### Paleoenvironment

*Main: Javelina Formation, Hell Creek Formation*

Main: Javelina Formation, Hell Creek Formation

*Quetzalcoatlus* lived 68 - 66 million years ago in the Javelina Formation, Texas and the Ojo Alamo Formation, New Mexico, USA, alongside animals like *Alamosaurus* and *Tyrannosaurus*. It is believed that the region it inhabited was a semi-arid inland plain, though, given the flight capabilities of *Quetzalcoatlus*, it is able to fly to habitats it prefers more.

In the Freshwater episode of Prehistoric Planet, female *Quetzalcoatlus* fly from North America to lay eggs in the swamp forests of South Africa, though it should be noted that, while azhdarchids have been found in the northern, eastern, and western parts of the continent, no azhdarchid remains have been discovered in South Africa yet, and *Quetzalcoatlus* is only known from the United States. However, such speculation is not unreasonable or implausible given the flight capabilities of azhdarchids, a significant factor that allowed the group to successfully colonize many parts of the world by the end of the Cretaceous. In North America, two *Quetzalcoatlus* get into a fight with a *Tyrannosaurus* over a dead *Alamosaurus* by the coast of the sea that split North America in half during the Late Cretaceous Period. While not the sort of creature to prefer coastal environments, the promise of a large body to scavenge is enough to attract the attention of this azhdarchid.

In 2002, an azhdarchid neck vertebra was found in southeast Montana. Though this bone is said to resemble the fifth cervical vertebra of *Quetzalcoatlus*, it is too distorted to fully determine which species the fossil belongs to. At the very least, an azhdarchid of equivalent size was present in the Hell Creek Formation. If proven to be *Quetzalcoatlus*, it would imply that the animal had a preference for more humid environments.

### Flight Capabilities

As with all pterosaurs, *Quetzalcoatlus* took off from the ground by means distinct from those of birds. To fly, birds jump off with their two legs, and some even need to run in order to take off. Pterosaurs, on the other hand, relied on the "quadrupedal launch" technique, as suggested by Dr. Mark Witton and Dr. Michael Habib, two of the experts who worked on Prehistoric Planet. With their muscular forelimbs and pectoral muscles, they are able to catapult their lightweight bodies into the air and achieve lift. Due to their more energy-efficient means of taking flight, the pterosaurs weren't restricted to the same body size and form limitations as birds, allowing them to achieve massive body sizes, with their flight muscles being 50 kilograms (110 pounds), making up 20 - 25% of the total body mass of the largest azhdarchids. One common misconception is that the different atmospheric conditions of the Mesozoic Era allowed pterosaurs to stay aloft better, though Dr. Darren Naish, Prehistoric Planet's lead consultant, clarified that pterosaurs only relied on their own power to achieve lift, and would be able to fly just fine even in environments like those of the modern day.

The exact dynamics of *Quetzalcoatlus* flight are still debated. While it very much likely flew, its wings clearly non-vestigial, working well in conjunction with its light weight and powerful muscles, some studies, like those of Dr. Michael Habib, say it can fly around 13,000 - 19,000 kilometers (8,000 - 12,000 miles), enough to traverse oceans and visit other continents. Other studies suggest that it didn't soar at all, and only flew short distances. Prehistoric Planet chose to go with the idea that *Quetzalcoatlus* could cover long distances in order to reach areas of interest, like isolated swamp islands that can keep their eggs and offspring safe from potential predators.

### Nesting Habits

***“ She's come here to make a nest. She chooses to do so on damp, swampy soil that will prevent her soft-shelled eggs from drying out. These first two are just the start. For the next three weeks, she will guard the open nest, and add two more eggs every few days. Producing eggs takes a lot of effort and energy. Each one is huge, weighing around a kilo. ”***

― **David Attenborough**, *Freshwater*
Pterosaurs are believed to lay leathery, soft-shelled eggs (each melon-sized egg being one kilogram in weight) much like lizards rather than hard-shelled eggs like birds. Hence, it is believed that, much like crocodiles and turtles, they buried their eggs (preferably in damp soil, as the *Quetzalcoatlus* did, to ensure they didn't dry out).

***“ Eventually, she produces a clutch of a dozen or so. She covers them with vegetation to conceal them. There should be enough food on this island to sustain her youngsters when they hatch. But there's nothing substantial enough here to satisfy her own hunger. She must leave to hunt for prey elsewhere... and trust that isolation of her nest will keep her unhatched young safe while she's away. ”***

― **David Attenborough**, *Freshwater*
The egg-laying strategy of each pterosaur varies. Some, like *Tethydraco* in Coasts, formed families in colonies to provide their young better protection against predators, and 215 pterosaur eggs found in Early Cretaceous China proved this to be the case for some species, and also imply a long period of parenthood that justifies reliance on this strategy for protection, for, based on the bone growth rings of the embryos preserved within the eggs, these particular pterosaurs took two years to develop before hatching. Others, like *Alcione* in Coasts and the azhdarchids in Swamps would bury their eggs in isolated areas, and leave the eggs be. *Quetzalcoatlus* is depicted relying on something similar to the latter strategy, except rather than simply laying her eggs in a communal nesting ground, she lays her eggs alone and, at the cost of her own energy, guards them up to their hatching, for others of her kind would view the existence of other eggs as competition rather than let them coexist with their own eggs, though this may be influenced by other factors, like insufficient food and other resources in the area.

***“ Another, much older Quetzalcoatlus female. She too is looking for a safe place to lay her eggs, and there may not be enough food here for two sets of giant nestlings. But there is a way to solve that problem... and, eggs, after all, are very nutritious. ”***

― **David Attenborough**, *Freshwater*
Overall, soft, leathery eggs are meant to be weight-saving adaptation. However, they are very delicate, and, given how much care is needed to prevent them from drying out, these types of eggs limited pterosaurs to laying them in specific environments and conditions, which was made clear when, in the Freshwater episode, another, older *Quetzalcoatlus* easily discovers the nest and, to prevent competition, destroys the nest and most of the eggs, eating some of them, resulting in a fight between the owner of the nest and the attacker to ensure whose spawn is guaranteed more success moving forward.

***“ The older female is driven off. But the younger female's nest is wrecked. Out of the dozen eggs that she laid, only three have survived. The success of her breeding season now rests on these three fragile eggs. She will protect them as best as she can until they hatch in a few months' time. But after that, her young will have to fend for themselves. ”***

― **David Attenborough**, *Freshwater*
The lesser the eggs, the more careful the mother is to ensure their survival. But, much like some snakes and sea turtles, once the eggs hatch, the mother leaves the young to fend for themselves, their survival no longer her responsibility. However, a combination of a baby pterosaur's ability to fly after hatching and careful selection of an isolated, food plentiful nesting sight chosen by their mother means that they can survive in relative peace until they're large and strong enough to leave their birthplace. Overall, Prehistoric Planet depicts *Quetzalcoatlus* as an r-selected species, an animal that spawns many children and provides them little to no parental care (in the case of *Quetzalcoatlus*, the little parental care they provide is only for the eggs, but not the juveniles themselves once they hatch), with the hope being that, even when many of them perish as they grow, many more will survive to adulthood and spawn the next generation.

### Feeding Preferences

The hunting and feeding preferences of azhdarchids like *Quetzalcoatlus* were discussed on the Prehistoric Planet: Uncovered segment "Could Giant Pterosaurs Really Hunt on the Ground?", which concludes that, since they were not agile enough to pursue airborne prey, and their necks were not strong enough to withstand the stresses of skim-feeding like various fishing birds, pterosaurs were likely terrestrial hunters, with preserved azhdarchid footprints supporting their ability to stalk prey on the ground. This was demonstrated by two other azhdarchids that also appeared on the show, *Phosphatodraco* and *Hatzegopteryx*. As one of the azhdarchids with slender, spear-like bills, *Quetzalcoatlus* more likely went after small prey items that are easy to swallow like small dinosaurs, as opposed to azhdarchids with short, deep, and blunt beaks like *Hatzegopteryx*, believed to be powerful adaptations for tackling and bashing live prey too big to swallow whole..

As opportunistic predators, azhdarchids likely also scavenged dead animals in order to conserve effort and energy that would otherwise be expended hunting live prey, using their beaks to reach deep into a body cavity and rip meat into smaller, more manageable pieces that can be more easily swallowed. This practice unfortunately puts them at odds with other large opportunistic predators trying to claim carcasses for themselves, like tyrannosaurs. This was first seen in the second segment of Deserts, which shows azhdarchids circling over a sauropod carcass, not coming down to feed on it until the pack of *Tarbosaurus* sleeping around it left the area. *Quetzalcoatlus* themselves would also be shown in a similar scenario in the first segment of North America, albeit with slightly different circumstances.

### Competitive Habits

***“ 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. ”***

― **David Attenborough**, *North America*
*Quetzalcoatlus* are also depicted as having the courage and ability to properly challenge the apex predator of their environment, *Tyrannosaurus rex*, as seen in the first segment of North America, where two of the pterosaurs challenged a *T. rex* for feeding rights to an *Alamosaurus* carcass, much like how modern-day scavenging birds, like corvids, vultures, and eagles, attempt to mob food from larger and stronger carnivores. *T. rex* weighs 30 - 40 times greater than the lightweight pterosaur, has a powerful, six-ton bite that can crush bone, and is capable of short bursts of speed when necessary. In the first segment of North America, a lone *Quetzalcoatlus* appeared a bit hesitant to approach a *T. rex* head on, though it slowly tried to creep in when the *T. rex* had its back turned, implying that it was still ready to try its chances in a confrontation even on its own. When a second *Quetzalcoatlus* arrived, however, the azhdarchids were more willing to exploit the few advantages they do have to challenge the *T. rex*. Due to their lighter build, large quadrupedal gait, and competent terrestrial mobility, they can move equally as fast and even be more agile than *T. rex* on the ground. Their ability to quickly quad-launch into the air at a moment's notice and attack from above is also a definitive advantage, though given the low agility of azhdarchids in the air compared to other types of pterosaurs, they may need large, open areas like a beach or plain to fully take advantage of their flight capabilities in such a conflict. *Quetzalcoatlus* also has a six-foot beak that gives it better reach, allowing it to strike opponents from a relatively safe distance. With all these traits, *Quetzalcoatlus* can effectively harass comparatively less-nimble foes and even pose legitimate dangers (like permanent blindness in both eyes, which can be a death sentence for any sight-reliant predator), all of which can prove sufficient to get even the likes of *T. rex* to leave if the risks they pose outweigh the urgency to feed.

Even so, the presence of rival predators is not necessarily completely detrimental in nature, and may in fact provide some benefits. *Quetzalcoatlus*, like most pterosaurs discovered so far, lack talons to help rend flesh, and, while their six-foot beaks are long enough to reach deep into a carcass and sturdy enough to eventually penetrate and rip even the tough skin of titanosaur cadavers on their own, large predators like tyrannosaurs first breaking open body cavities and bones with their powerful jaws to expose the more edible parts of a corpse does help the azhdarchids access these more valuable parts of a carcass like bone marrows quicker and easier, saving stress and effort on their end.

## References

### General

1. ↑ 1.0 1.1 1.2 An Azhdarchid Pterosaur Cervical Vertebra from the Hell Creek Formation (Maastrichtian) of Southeastern Montana
2. ↑ 2.0 2.1 2.2 Review of taxonomy, geographic distribution, and paleoenvironments of Azhdarchidae (Pterosauria)
3. ↑ 3.0 3.1 3.2 3.3 Peerless Pterosaur Could Fly Long-Distance For Days
4. ↑ Did giant pterosaurs vault aloft like vampire bats?
5. ↑ How did extinct giant birds and pterosaurs fly? A comprehensive modeling approach to evaluate soaring performance
6. ↑ Pterosaur egg with a leathery shell
7. ↑ Mother Pterosaurs Laid Soft Eggs, New Fossil Hints
8. ↑ These flying prehistoric reptiles had needy babies, rare batch of eggs show
9. ↑ Walk the dinosaur: New biomechanical model shows *Tyrannosaurus rex* in a swinging gait
10. ↑ New Study Finds *T. rex* Walked at a Slow Pace of Three Miles Per Hour

### Dr. Darren Naish

1. ↑ 1.0 1.1 *Quetzalcoatlus* may have laid as many as 12 eggs at a time, fitting for a 220-kilogram (485-pound) animal.
2. ↑ A lot went into the portrayal of the launching dynamics, sounds, and combat style of Prehistoric Planet's azhdarchids.
3. ↑ The pterosaurs of Prehistoric Planet are depicted making deep drumming or booming sounds based on analogy with living archosaurs.
4. ↑ Pterosaurs breathed in bird-like fashion and had inflatable air sacs in their wings
5. ↑ Pterosaurs would have preferred to lay their soft-shelled eggs in damp substrates, and the average azhdarchid egg is estimated to weigh around a kilogram.

### Dr. Mark Witton

1. ↑ 1.0 1.1 Clipping the wings of giant pterosaurs: comments on wingspan estimations and diversity
2. ↑ Why pterosaurs weren't so scary after all

### Dr. Mark Witton and Dr. Darren Naish

1. ↑ Azhdarchid pterosaurs: water-trawling pelican mimics or "terrestrial stalkers"?

### Dr. Michael Habib

1. ↑ Comparative evidence for quadrupedal launch in pterosaurs

### Dr. Michael Habib and Dr. Mark Witton

1. ↑ 1.0 1.1 On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness

### Prehistoric Planet

1. ↑ 1.0 1.1 As stated in North America.
2. ↑ 2.0 2.1 As stated in Prehistoric Planet: Uncovered - What Else Lived Alongside The Dinosaurs?
3. ↑ As stated in Prehistoric Planet: Uncovered - Could Giant Pterosaurs Really Hunt on the Ground?