Alcione

AlcioneKingfisher
Classification
Domain	Eukaryota
Kingdom	Animalia
Phylum	Chordata
Subphylum	Vertebrata
Superclass	Tetrapoda
Clade	Sauropsida
Class	Reptilia
Clade	Archosauria Avemetatarsalia Ornithodira Pterosauromorpha
Order	Pterosauria
Suborder	Pterodactyloidea
Clade	Ornithocheiroidea Pteranodontia Aponyctosauria
Species	Alcione elainus
Presence
Location	Ouled Abdoun Basin, Morocco, Northwest Africa
Temporal Range	66 million years ago, Maastrichtian Stage, Late Cretaceous Period
Episodes	Coasts (Segment 2) Islands (Segment 1)
Characteristics
Wingspan	1.8 - 2.4 meters (6 - 8 feet)
Diet	Piscivorous
Took at least five years to grow

“ Beneath this pile of seaweed, something is stirring. A tiny Alcione hatchling, just a few inches high, and weighing less than two ounces. ”

― David Attenborough, Coasts

Alcione (named after "Alcyone", a female figure in Greek mythology who was transformed into an "alkyṓn" or "halcyon bird", known today as a "common kingfisher") is a genus of pteranodontian pterosaur that lived in the Ouled Abdoun Basin in Morocco, North Africa, 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

Paleobiology

“ Their bones are extremely light, up to 90% air, and that makes the effort needed to take off much easier. Even so, test flights are essential. There will only be one chance to get it right when the time comes to launch. ”

― David Attenborough, Coasts

Alcione is a small pterosaur with a mere wingspan of 1.8 - 2.4 meters (6 - 8 feet), and is otherwise much like typical pteranodontians, with a toothless bill suited for catching fish. Although it is just outside of the actual nyctosaurid family, Alcione, like Barbaridactylus and other nyctosaurids, is depicted on the show without proper fingers aside from the elongated ones that support its wings. Because of their lack of functional fingers, it is believed that nyctosaurids (and similar pterosaurs, like Alcione and other aponyctosaurians) spent almost all their time in the air, and, in the rare times when they stayed on the ground, walked on the joints of their wings where their hands would normally be.

On Prehistoric Planet, Alcione chicks are shown to have a pycnofiber coat of white and dark brown spots, which can help camouflage them when young. The adults appear to be based on gannets, with yellowish-white coats and faces that are either blue or yellow. It is not clear what this is meant to indicate, though it is likely that this coloration is a variation based on the animal's sex.

Paleoecology

Paleoenvironment

Main: Ouled Abdoun Basin

Main: Ouled Abdoun Basin

“ It's especially rich here in the North Atlantic, where huge shoals of fish come close to the shore. One kind of animal thrives in such places and forms immense colonies. Flying reptiles, pterosaurs. Here, on the beaches of North Africa, there are seven different species of them. They come here to feed, to rest, and to raise their young. ”

― David Attenborough, Coasts

It was once believed that pterosaurs declined in diversity towards the end of the Cretaceous. But on the shores of what would one day become the Ouled Abdoun Phosphatic Basin, west of the Atlas Mountains, seven different species of pterosaurs (among them Alcione, Tethydraco, Phosphatodraco, and Barbaridactylus) showed that, up to the end, the pterosaurs were successful and diverse, only to be abruptly rendered extinct by the Cretaceous-Paleogene Extinction Event, which wiped out three-quarters of life on Earth 66 million years ago.

An Alcione appears in the seas of southern Europe in the first segment of Islands. While Alcione isn't known from this area, the distance from Morocco to southern Europe is not too great, and there is evidence of nyctosaurids in the area, thus, its presence there is plausible.

Nesting and Parental Habits

“ But some pterosaurs are less well-adapted to life on land. They have a slightly different nesting strategy. They make their nests where they will attract less attention from predators. Isolated cliffs like this are ideal. Pterosaur eggs are leathery, and can easily dry out, so they need to be covered. ”

― David Attenborough, Coasts

While Alcione adults are shown freely mingling with other pterosaurs on the beaches of Morocco, they are said to be less well-adapted to land. Hence, they lay their eggs far from the reach of others, in isolated offshore islands, with piles of seaweed covering the eggs to keep them from drying out. Pterosaurs are believed to lay leathery, soft-shelled eggs 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 in Freshwater, to ensure they didn't dry out). While this allowed for weight-saving adaptations, it limited pterosaurs to laying eggs in specific environments and conditions, which was made clear when, in Coasts, while the young Alcione are safe within the offshore island on which they were born, they need to leave for the forests on the mainland, past the coast, in order to find sustenance.

“ Hatchlings from hundreds of nests gather on the clifftop to prepare for their first flight. But their wings are still unformed. The bones of the long finger that supports their wing membrane must first straighten and lock together, and that will take some hours. But they can't stay here for long... ”

― David Attenborough, Coasts

A majority of modern-day flying vertebrates are incapable of flight early on in life. Most birds, depending on the species, must be around 10 days to 12 weeks old before being capable of flight. There are, however, exceptions, like megapodes and other galliform birds, which are capable of flight in a few days, or even on the very day they hatch. In a 2021 study by Dr. Darren Naish, Dr. Mark Witton, and Dr. Elizabeth Martin‑Silverstone (all three being involved in the making of Prehistoric Planet, with Dr. Naish serving as the show's lead consultant), pterosaurs are superprecocial, capable of extreme locomotor movements (including flight) shortly after hatching. By wing area to mass ratio, juvenile pterosaurs can out-glide living volant animals, and their wings are more suited for active, sustained flight as opposed to short-distance gliding. Additionally, the humeri (upper arm bones) of juvenile pterosaurs are also thick and robust in proportion to their length, allowing them to withstand great stress and further supporting the idea that they engaged in active flapping early on.

“ Their mothers left the eggs here about two months ago. Calling to each other synchronizes hatching; there is safety in numbers. ”

― David Attenborough, Coasts

As shown by several species on Prehistoric Planet, pterosaurs, much like animal groups today, likely varied in lifestyle. Unlike the young Tethydraco, which are raised by their parents on the beaches of Morocco, Alcione chicks start life independently. They have a slight connection, synchronizing their hatching time so that there are as many of them as possible. Mere hours after their birth, they embark on their first flight (which they are understandably hesitant to take on at first) in a dangerous journey over the ocean, pursued by predators (and here, their safety in numbers comes into play, at the expense of the few who are caught and eaten). Should they survive this and make it to sanctuary, their future is slightly more secured. By this speculative depiction of Prehistoric Planet, Alcione is shown to adhere to the r-selection strategy, since animals that take on this type of strategy rely on spawning many offspring that are given little to no parental care (with many of them not expected to survive), are born in a short span of time (stated to be two months for Alcione), and mature in a short span of time (stated to be five years for Alcione). Overall, the show portrays Alcione as an r-selected species, an animal that spawns many offspring, and thus does not provide extensive parental care, since most of the juveniles are not expected to reach adulthood, with many dying while many more survive to bring forth the next generation.

Cautious Behavior

A weary Alcione is seen resting on debris drifting on the ocean in the first segment of Islands. Although at rest, the pterosaur is shown to be alert and quickly responsive to threats it may sense in the area, hence, it quickly flew off just before the drifting debris it was on got attacked by a hungry Prognathodon.

Appearances

Coasts

In the second segment of Coasts, which takes place on the shores of Northern Africa, a colony of the Tethydraco is seen on a beach. Within the colony are a few Alcione and Barbaridactylus. The pterosaurs are on the beach to rest and raise their young. One Tethydraco hatchling is seen wandering around, though its mother quickly ushers it back in place to keep it from wandering too far from the nest. The concerns of the parents are justified, for, wandering the beach, is an opportunistic predator.

“ Tethydraco are well-adapted to spend their time on the ground, and not only make their nests here, but stay to protect their brood. And their young certainly need protection... The dagger beak of Phosphatodraco. The nine foot-tall predator that stalks through these colonies, looking for a chance to snatch an unguarded hatchling. ”

― David Attenborough, Coasts

The Tethydraco clack their beaks to keep the larger pterosaur away from their nests and chicks, though the Phosphatodraco remained undaunted, completely disregarding these warnings as it continued patrolling through their colony.

Meanwhile, in some offshore islands, newly-hatched Alcione chicks emerge from beneath piles of seaweed. As they chirp, even more of them hatch and come out. By instinct, hundreds climb to the top of the cliff, doing short test flights as their wings slowly form up. The updrafts formed by the cliff edge provide favorable conditions for them to fly all the way to their destination, the mainland. Even so, there is initially an air of hesitance, until finally, one hatchling flies off, prompting the rest to follow suit. They're not heading for the colony on the beach, but the misty forest on the cliffs beyond the beach.

“ Barbaridactylus. Powerful predatory pterosaurs that normally catch fish, but the hatchlings are too good to miss. One way to take evasive action is to simply fold their wings and drop. But losing height will make it harder for them to reach the forests. ”

― David Attenborough, Coasts

Unfortunately, the journey there is not straightforward. Sensing an easy meal, three Barbaridactylus swoop in and snap up some of the hatchlings in midair. The juvenile Alcione fold their wings and drop, momentarily evading their predators at the cost of lost height. Some end up flying too low to the ocean, and are easily grabbed by the Barbaridactylus. One unlucky Alcione hatchling crashes down on the beach, attracting the attention of the Phosphatodraco prowling the colony. The Tethydraco look on as the Alcione hatchling tries to stand up, while the opportunistic azhdarchid closes in on it, clacking its beak in satisfaction before grabbing the hatchling, devouring it as it screeched its last. The Tethydraco give one last glance as the predator swallowed and savored its meal, serving as a reminder of what fate could befall their chicks should they be left unguarded, before one turned its attention back to the Alcione that are still airborne, trying to escape the Barbaridactylus.

“ A lucky survivor from the first wave of hatchlings, still heading in the right direction... sanctuary. Of the hatchlings that left the stack, few get as far as this. But for them, this forest offers all the shelter and food that a young pterosaur needs. For the next five years, this will be their home, then, they will be large enough to join the adults catching fish out on the open ocean. ”

― David Attenborough, Coasts

One hatchling is shown, still being pursued by a Barbaridactylus. It manages to finally reach the cover of trees, prompting the predator to stop just short of the forest and fly off at last. This survivor, among a few others, gather in the safety of the trees, resting and flapping their wings as they watch the open ocean. The segment ends with a shot of five adult Alcione flying across the ocean, giving the hatchlings a glimpse of the future ahead of them.

Islands

“ The mouth of a river in southern Europe, 66 million years ago. In the aftermath of a tropical storm, debris is drifting downstream. And amongst the wreckage, rafts of wreckage ripped from the land. For a weary pterosaur, this one may be a welcome place to rest. But it's far from safe... ”

― David Attenborough, Islands

In the first segment of Islands, a weary adult Alcione rests on a collection of vegetation in southern Europe, a raft drifting out of a river into the sea. For a moment, it feels safe, flapping its wings as the raft drifts on peacefully. But suddenly, sensing that something is wrong, the Alcione takes to the skies just as a hungry Prognathodon lunges at its raft.