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Darwin IV is a fictional planet that was the subject of Wayne Barlowe's book Expedition and the television special, Alien Planet, based on Expedition. Although the details of the discovery and exploration of Darwin IV differ in the two presentations, both are essentially the same in their depiction of the planetary environment and its native life-forms, whose abundance and variety prompt the name Darwin.
In Alien Planet, a more basic scenario is presented where a ship called the Von Braun is sent to explore an alien world outside the solar system. The Von Braun is sent to a binary star system about six and half light years from Earth. At 20% of the speed of light (0.2c), it takes over 40 years to travel to this system. Upon arrival it goes into orbit around Darwin IV, the Von Braun deployed the Darwin Reconnaissance Orbiter to scan the planet from orbit. The Von Braun also dispatches three identically shaped lighter-than-air probes to the planet surface. These three probes are:
- Leonardo da Vinci (nicknamed "Leo" and colored blue).
- Isaac Newton (nicknamed "Ike" and colored yellow).
- Balboa (named after Vasco Núñez de Balboa and coloured red). Balboa did not survive entry into the Darwin IV atmosphere, because one wing of its lifting body transport failed to unfold. (Balboa was evidently doomed from the start — the screenwriters of Alien Planet never proposed a nickname for it, and it wasn't named in full name.)
Oddly, the binary star system best fitting the described one above is Luhman 16, as it is a binary system of brown dwarfs 6.59 light-years away, though it is questionable whether a brown dwarf could actually support life.
Geography and evolution
It seems likely that Darwin IV was covered with large oceans a few million years ago, just like Earth. But because of important climatic changes, the oceans evaporated and most of the ocean water became part of the atmosphere of the planet. The continents are now mountain chains and plateaus, while the ocean floor has become a large, open plain of deserts and savannah. Thus, most of the creatures who now inhabit Darwin IV are descendants of land-dwelling animals
The dense atmosphere is full of clouds and meteorologic activity and the plains sometimes resemble "weather oceans". Most of the water is found in the atmosphere, but there are also millions of tons of frozen water in the regions of the poles, and big lakes and rivers where the 'pocket-forests' reside.
In the deepest part of the evaporated ocean basins, there is a "lake", the Amoebic Sea, composed of tons of microscopic creatures who have evolved to conserve the last of the remaining sea water inside their bodies in order to survive.
The continental plates are still moving, and the areas where they collide are full of earthquakes and volcanic activity, phenomena that remain mostly unseen on Earth since there they occur under the surface of the oceans.
The species on Darwin have all evolved sonar, echo-location using a variety of sounds as their primary sense, rather than perceiving light, as most animals on Earth do. Many have complicated cephalons to aid in this sense. The majority have also evolved biolights; but rather than communicating information in the visible light spectrum, biolights on Darwin IV function in the infrared range, as all Darwinian animals are quite sensitive to that spectrum. It is important to note that their sensory organs to detect light in the infrared spectrum are more comparable to thermoreceptors found in pit vipers or rattlesnakes. The Rimerunner still has one bizarre, retractable, atrophying eye, a remnant from a time when sight-based organisms still had a place on Darwin IV. Also, most species are hermaphrodites.
List of species
Below is a list of the species found on Darwin IV. NOTE: Species marked with a "*" are featured in both the Alien Planet TV special and the book Expedition. Unmarked species are found exclusively in the book.
All species in Alien Planet were mentioned or depicted in Expedition; however, it should be noted that the Electrophyte was only briefly depicted in the book and was only fully explained in Alien Planet.
- Amoebic Sea* - The Amoebic Sea is a gelatinous sea of single-celled organisms. All the water in the Amoebic Sea is absorbed and sealed within the gelatinous mass to prevent further evaporation, as the planet is slowly losing water over the eons. It is home to Emperor Sea Striders and Sac-backs. Littoralopes often visit the Amoebic Sea, eating the organisms. Tentacles come out of the surface of the Amoebic Sea and trap Emperor Sea Strider Nymphs, then consume them alive.
- Arctic Sedge Slider - A ten-meter-tall biped, the Arctic Sedge Slider is adapted for life in the cold. The Arctic Sedge Slider's name comes from the furrows it leaves in its wake. This creature has an adaptation for the cold. When temperatures drop, or when a fierce Arctic storm approaches, the Arctic Sedge Slider has the ability to retract its head deep into its warm body cavity. When conditions are favorable again, its head reemerges again and it resumes its activities. The Arctic Sedge Slider has what may be the biggest sonar bulge of any animal on Darwin IV. This massive organ produces sonar pings in, not one, but multiple frequencies. Since the bulge is located on the Arctic Sedge Slider's back, it gives the animal the ability to "see" in 360 degrees. This makes it much more difficult for a predator to catch an Arctic Sedge Slider by surprise. A pair of Arctic Sedge Sliders with Ice Darts.
- Arctic-Strider - An Arctic bipedal alien that stores fat in its legs.
- Arctic Tripedalien
- Arrowtongue* - A bipedal alien with black coloration and red spotted biolights. Averaging about eight meters tall, an Arrowtongue impales its prey with a 3 meter-long, serrated, arrow-tipped proboscis. Like many spiders on Earth (and like most predators on Darwin IV), Arrowtongues are liquivores, injecting digestive juices into their prey and then sucking up the liquefied organs. They are fierce, solitary hunters found on the grasslands of Darwin IV. Like most of Darwin IV's animals, their pointed, spade-like heads contain no true jaws. They use sonar in order to find other species and food.
- Beach Loper - The Beach Loper is a bipedalien with a trunk like an elephant's. It probably feeds on microflyers. It is a distant peripheral cousin of the immense Emperor Sea Strider.A Beach Loper being attacked by a swarm of Beach Quills
- Beachquill* - Beach Quills are short-range attack hunters and are some of the smallest creatures on Darwin IV. They attack in colonies and kill their prey with a neurotoxin. In Alien Planet a large colony kills a Groveback. They can propel themselves by means of a folded muscular "foot". The beach quills in Expedition were one meter in length as opposed to the 3-inch (76 mm) long beach quills in Alien Planet. An image of a Beach Quill.
- Beach-Runner - A bipedalien with long legs that sprints along the shore of the Amoebic Sea.
- Beach-Dweller - A tripedalien with long legs that lives along the littoral zone of the Amoebic sea.
- Belly-Thrower - A monopedal animal which has an eating habit similar to that of a starfish on Earth; it inverts its stomach outside the body and catches prey in it.
- Bladderhorn* - This creature is a bright blue, rather comical-looking bipedal animal, with two "antlers" extending out of the sides of its head and have red biolight markings on them. The antlers are actually sacs designed to inflate and make it look much larger than it truly is. Bladderhorns make bellowing sounds by deflating the air sacs. The Bladderhorn uses its "antlers" for communication, which, in Alien Planet, causes Leo to conclude it is a good candidate for communication. Leo shows the Bladderhorn a symbol puzzle, but the Bladderhorn becomes apparently agitated, bellowing at him, and then runs away. Actually, the Bladderhorn ran away because of a sonic ping. Ike sees the same Bladderhorn near the conclusion of the exploration. Bladderhorns fight with their bladders like antlers, using bioluminescent light shows and their bladders to scare away predators and rivals.
- Bolt-Tongue - A polar cousin of the Arrowtongue, the Bolt-tongue is a Darwinian predator which uses a large arrow-tipped appendage to kill its prey. The bolt-tongue possesses a sonar bulge in the form of an arc running down its head. Like all predators on Darwin IV, it has no eyes. The head of a Bolt-tongue.
- Butchertree* - Many species prey on the numerous, fast breeding Prismalope, but the Butchertree is the only species that actually lures the Prismalope instead of chasing it. Dotting the plains of the northern hemisphere, the Butchertree kills anything that comes within range of its four branch-daggers. They have a bizarre relationship with an unnamed flying organism, which is the primary food source of Prismalopes. The Butchertree grows underground roots that resemble these fliers, allowing the "tree" to lure Prismalopes close enough to try to kill and eat them. It is unknown just how this species reproduces. One possibility is that the small flier it associates with transfers eggs and sperm between individuals. Another possibility is that the flier itself is the second gender of the species, an extreme form of sexual dimorphism. Either way, young Butchertrees are found close to their "parent", and are connected to them through an umbilical cord similar to that of the "growths" that mimic the fliers. The cord disappears once the young are capable of nourishing themselves. In Alien Planet the Butchertree is one of only two species shown to prey on Skewers. A sketch of a butchertree.
- Brain-Balls - Brain-like creatures in the background of the waterhole. Described by Barlowe as "huge, colonial earthbound floaters".
- Carver Wing - An incredibly aggressive ectoparasitoid flyer that lays its eggs on the dorsal survases of large animals. Once the eggs hatch, the Carver wings will devour their host.
- Cragspringer - A wingless cousin of the Springwing that is also a mountain-dweller but is more of a leaper than a glider, as it lacks the gliding wings of a Springwing.
- Daggerwrist* - The Daggerwrist is a human-sized tree-dwelling carnivorous animal. It glides from tree to tree with the assistance of thin membranes, or patagia, similar to those of a flying squirrel. Its forelimbs are large daggers designed for clinging to plaque-bark trees and killing prey, mainly Trunk-suckers. Unlike most of Darwin IV's predators, the Daggerwrist has what could be a jaw, but it is actually part of the skull that detaches to stab its prey and inject the needed digestive enzymes. This organ is connected to the chest of the Daggerwrist by a chord and is often tucked under the head, giving the jaw illusion. A sketch of a Daggerwrist gliding, a sketch of a Daggerwrist's head.
- Diskflyer - Diskflyers live around the Amoebic Sea and operate within very distinct four square kilometer territories. It is not known whether young Diskflyers stay within the territories in which they were born or if they leave to establish new territories of their own. Diskflyers are hermaphroditic, like most of Darwin IV's fauna, and mating impregnates both partners. It is not known whether diskflyers give birth to live young or eggs.possibly related to skewers.
- Ebony Blister-wing - An immense flier, the Ebony Blister-wing can sometimes attain wingspans in excess of 1,000 feet (300 m).
- Emperor Sea-strider*- The Emperor Sea-strider is the largest known creature on Darwin IV. In Alien Planet, the Emperor Sea-strider is 70 feet (21 m) tall, but it is much more massive in the book Expedition. Though their exact size is unknown, if Mr. Barlowe's account is correct, they would be 620.1 feet (189.0 m) tall. Emperor Sea-striders walk on the surface of the Amoebic Sea with their two massive feet. Emperor Sea-striders are found only on the Amoebic Sea because the sea is the only source of food in numbers large enough to support such creatures, much like krill is for baleen whales on Earth. When Emperor Sea-striders are born they are capable of flight, but as adults they are bipedal. Hatched from eggs, the tiny Sea Strider Nymphs are attracted to an energy source located beneath the adult's mouthless head. Hollow, light-weight creatures, they cannot yet walk, but they fly about Darwin IV on their short wings, like Earth's hummingbirds. They have an unusual method of feeding; their mouths are located on their feet, so it eats the organisms by stepping on them. The identifying traits they have are a mouthless crested head, two very large orange biolights (which are cavities in the book), two large tails (which is actually a tail and a phallus according to the book), and smaller blue biolights accenting their crests and tails. A sketch of Sea Strider Nymph
- Eosapien* - Eosapiens are the sentient natives of Darwin IV in both Expedition and Alien Planet
. The Eosapiens appear to be highly mobile, airborne, and semi-sentient. They possess limbs with tentacle-like fingers as well as claws, navigate with organic rudders, and use large sacs of methane to provide lift. Eosapiens have rudimentary intelligence roughly equivalent to that of our own early ancestors like Homo erectus. They carry spears and spikes for hunting. In the book, they dropped these weapons to make a cage around prey and then lift them away. They also seem to harvest the floating balls of gel the Amoebic Sea produces. The Eosapiens seemed to have gathered stones and arranged them in a circular pattern around Leo, like prehistoric monuments such as Stonehenge. Their name means "dawn thinker" in Latin because of the time when Barlowe first encountered them. In Alien Planet they were one of only two species able to prey on Skewers, but they most often feed on Gill-heads. Leo was assaulted by an Eosapien shortly after trying to communicate with a Bladderhorn. A group of Eosapiens apparently interpreted a camera disk launched by Ike as a threat; the last image from the camera disk showed the Eosapiens flying away, carrying a limp Ike. The floating balloon probe resembles the floating Eosapiens, and the launch of the video disc was probably interpreted as throwing a weapon. This species differs in appearance in the book compared to Alien Planet. In Alien Planet, the Eosapiens fingers were made more tentacle-like and longer, and they increased the size of its bladders, had spears instead of spikes, their skin color (reddish-pink instead of blue-green, both had yellow biolights) and hunting strategies also differ from what is found in the book. Barlowe's version of an Eosapien with a spike.
- Fin Leg - Small, silver, barrel-shaped herbivores with two fin-like limbs, hence the name. Even though it only has two fins, it walks on four points, two on each fin. They feed on the semi-liquid membrane of the jelly-bladder plants. Small colony of Fin Legs (bottom-left corner).
- Finned Snapper - A carnivore with 2 front legs and an airfoil like hind quarters that lifts it when it runs. They feed on Jetdarters by flicking their agile and dexterous hunting arm located on the head. They are very light weight and have very delicate bones. The individual encountered by Barlowe was injured when the hovercone's engine tossed the animal, where it was later assaulted by jetdarters.
- Flipstick - Flipsticks are tremendously tall, cylindrical animals. The Flipstick's signature form of locomotion involves leaping into the air and flipping 180° to land on its opposite end. These 60-meter-tall (196 feet) creatures feed on microflyers by jamming their sonar with an oscillating tone, then scoop them up in feeding scoops. Four Flipsticks in an area showing Fin-legs, Jelly-bladder plants, and Gelsuckers.
- Follow-wing - Small blue flyers that usually follow Skewers to scavenge from their kills. They are related to the Skewer, but they are only 2 meters long.
- Forest Gulper - A large animal that lures animals into its mouth by scent, then slowly digests them alive. They resemble a giant green barrel with a thick snake-like tail, and a pair of atrophied beating wings. These wings are used for flight in the Gulper's larval stage, but become vestigial as the animal matures. This creature is one of the last animals with true jaws ever on Darwin IV, one of them being the Groveback.
- Forest Slider - Forest Sliders are bipedal animals that are born with four limbs, but as their rear skid hardens and matures, their hind limbs shrivel and eventually fall off. A Forest Slider drinking from a stream in a forest with Hooked-tailed Flyers, a young Forest Slider with one of its hind limbs shriveling away.
- Gelsucker - The Gelsucker is a quadruped, but also has a pair of clawed arms, giving it a total of six limbs. Gelsuckers are so called because they feast on the flesh of the Jelly Bladder plant, which grows in small groves on the outskirts of pocket forests. They use their clawed arms to rip the Jelly Bladders open, and then use their extendible proboscis to suck out the semi-solid flesh. Two Gelsuckers in an area with Flipsticks, Fin legs, and jelly-bladder plants.
- Gill-Head - A biped with a spike on its chest to support it, almost like a third leg. They are one of the last remaining terrestrial air-sifters, such as the Rime-Runner. The Eosapiens prey upon it.
- Groveback* - The Groveback is perhaps the second largest creature native to Darwin IV. When fully mature, they are large enough to have entire stands of trees grow on their backs during the long periods of dormancy spent buried in the ground. Once mobile, they travel on two large front legs and a rear appendage shaped much like a boat rudder. The feeding habits of the Groveback differ between the book and the film. In Alien Planet, the Groveback feeds by absorbing nutrients from the soil through the skin of its underbody. In the Expedition, the Groveback is a filter feeder, feeding on the microscopic plants and animals that number in the millions in Darwin IV's air currents. Considering the Groveback's size and speed, the first mentioned lifestyle may sound more realistic, but when considering the multitude of slow filter feeders and a many nostril-like orifices covering the Groveback's head, the latter lifestyle is just as possible. The Groveback is one of the many creatures on Darwin IV with true jaws. A sketch of Groveback
- Gyrosprinter* - The "antelope" of Darwin IV. However, unlike the antelopes of Earth, the Gyrosprinter has just two legs arranged in a rather unconventional manner - one right behind the other. The legs appear to have evolved to become fused from two forelegs and two hind legs over millions of years; the Gyrosprinter's ancestors were probably once quadrupeds like Earth's quadrupeds. Unfortunately, such a placement of legs can be a problem for balance. The Gyrosprinter has solved this by having two balance organs (similar to the inner ear of a human) located in two thick prongs protruding from either side of its body. It has two hearts, a two meter long tongue, and its nostrils are located on its shoulders. The Gyrosprinter is able to run at speeds of up to 80 km/h and has a running stride of up to 15 meters.
- Hammer-headed Veldt Wing - A hooded grassland flyer that has crescent-shaped head on the end of a skinny neck. It is on the Rayback menu. Hammer-Head Veldt Wing being chased by a hungry Rayback.
- Hook-tailed Flyer - A yellow, medium-sized flyer with a hooked tail and a single float bladder.
- Hopper-Cone - Small animals that steal scraps of Jelly-bladder plants ripped open by Gelsuckers.
- Ice Crawler - Quadrupeds that resemble pillbugs are nearly motionless and make comically flatulent noises when emerging from their "sleep sack". Ice Crawlers on a beach with Rime-runner
- Ice Dart - A small flying animal that has three pointed tubes for feeding and drinking, one on its face, another on its bottom sides, and a third one on its rear. It also pokes itself on ice during snow storms.
- Jetdarter* - One of Darwin IV's more bizarre aerial life forms. The Jetdarter is a scavenger whose compact body assumes a dart-like shape. It has no wings to aid in flight. Instead, it has a biological version of a ramjet engine - complete with a turbine of bone and gristle. It has two legs which fold up during flight, although on Alien Planet, they do not appear to have legs at all. The Jetdarter forms nests in the pocket-forests and fears many predators, such as Electrophyte plants and Finned Snappers. Anatomical sketch of a Jetdarter, Image of a Jetdarter.
- Keeled Slider - The Keeled Slider is a large brown animal with kneeled arms. It builds special egg chambers to keep eggs and young. It slides down muddy mountains. It is not hermaphroditic. Two Keeled Sliders.
- Littoralope* - The Littoralope are the creatures that use huge Sea-Strider skulls for shelter in Expedition. In Alien Planet, the Littoralopes are described as placid, slow-moving quadrupeds with little evidence of intelligence. They also have tails resembling their heads, similar to Symets, which did not appear in Alien Planet. This feature probably evolved to confuse predators. Photo with Littoralopes living inside of a Sea Strider's skull, Alien Planet version.
- Micro flyers Micro flyers do the function like zooplankton on earth.
- Mummy-nest Flyer - They are black flyers, with a tail that bends back to meet the front of the body (like scorpions, except the tail is curled under the body, not above). Unlike some flyers, they are not jet propelled, so they have to flap their wings to fly. They probably look like miniature versions of the gargantuan Ebony Blister-Wing Barlowe hypothesizes that the flyer was once part of the Mummy-nest and, as it matured, broke off from it and used its former body as a home.
- Mummy-nest - This animal has sphincter-like orifices on its body. It is later invaded by Mummy-nest Flyers (though they may have once been one and the same).
- Prairie-ram - Prairie-rams are ubiquitous liquivores that impale their prey's chest to suck out bodily juices. Picture of a Prairie-ram.
- Prismalope - A tripedalien of Darwin's plains, Prismalopes often travel in herds. The first thing one notices about this creature is its massive prism-shaped head. Though it appears ungainly, it houses the Prismalope's grasping tentacles, which it uses to capture small prey. This fast-breeding creature is preyed upon by a multitude of predators, both terrestrial and airborne. The Prismalope hunts a flyer that is "protected" by the Butchertree. Prismalopes with Butchertrees in the background.
- Prongheads* - Prongheads are bipedal plains predators that feed on Gyrosprinters, Symets and Littoralopes. They are named for the three hollow prongs protruding from their faces that act as tubes to siphon liquids from their prey, since they use their feet to inject their digestive fluids into prey. They hunt in pack in a similar manner to wolves on Earth. A Pronghead surveying the plains in search of prey, Image of Pronghead in Alien Planet.
- Rayback - An agile and aggressive predator of Darwin IV's grasslands. This creature gets its name for the four tall ridges that project from its back. Apart from its ridges, the Rayback does not appear to have any specialized features. Its only weapons are its lightning-fast speed and a dagger-like tongue. It is fierce and attacks anything that moves. It was the first animal encountered by Barlowe, and apparently, his sudden appearance caused it to start attacking him and his vehicle. A biped, it bears a general resemblance to the Bolt-Tongue and Arrowtongue. Picture of Rayback.
- Rimerunner - The Rimerunner is a one-legged animal from the polar regions of Darwin IV. Supported by only one leg, the Rimerunner hops across its Arctic home like a kangaroo. It eats only aerophytes and other microscopic airborne organisms. At the front of its head, the Rimerunner sports an umbrella-like organ. This organ, suspended by thin neural cables, is a sophisticated sonar system along with a simple and atrophying eye. Picture of a Rimerunner.
- Rugose Floater - Rugose Floaters are heavily wrinkled, fish-like aliens about the size of a blue whale that float in the air. During spawning season, they have eggs trailing behind their "fins" and reduce to their crescent shape when spawning is complete. This is the creature seen on the front cover of Expedition and at the top of this web page. Picture of a Rugose Floater.
- Sac-back - The Sac-back lives at the edge of the Amoebic Sea. The Sac-back gets its name from the sac on the male's back. The sac is used to store pre-digested food from the "sea", which is later fed to the females. Male and female Sac-backs live completely different lives. Males live on the surface, walking around on their three legs. Female Sac-backs dig "tombs" in which they bury themselves. Once buried, the only part of the female that sees the light of day is her mouth and tentacle.
- Scavengewing - Scavengewings are flying animals that have a special digestive system suitable for eating carcasses. The animal completely separates it from its body, dropping it on carrion, then swallows the feeding module.
- Siphon Floater - The large floating creature around the waterhole
- Siphonsnout - The small purple creature around the water hole.
- Skewer* - The largest aerial predator of Darwin IV. It is a humungous flying animal, with a wingspan of 50 feet (over 15 m). Not even the largest known pterosaurs (like Quetzalcoatlus, with its 40-foot (12 m) wingspan) from Earth have a wingspan even approaching that size. Its wings do not flap but squeeze, shifting shape to shift flight. It is actually propelled by combusting methane gas in four jet-pods on its wings. This allows the Skewer to travel at speeds of 200 miles per hour. Its killing tool is a hollow lance that impales its prey, injects digestive enzymes, and sucks the corpse dry. The Skewer also hunts in groups, each Skewer dropping the spoils and another swoops in to feast. No large animal on Darwin IV is safe from the skewer. Barlowe mentions an eyewittness attack on a sea strider by skewers, but the way this was done is never mentioned.
- Spade-nose - A quadruped that lives in forests and has a blue spade-like nose, hence the name. It is a common prey of the Gulper. Image of a Gulper about to devour a Spade-nose.
- Springwing - The Springwing is a winged animal with hooved front legs. The appearance of a Springwing is reminiscent to that of a hippogriff. It springs itself off cliffs, gliding with the alpine updrafts to reach its destination Photo of a Springwing.
- Stonemime - An oval-shaped animal with eight legs. It can mimic a rock.
- Stripewing - The Stripewing is an odd two-meter-tall flying creature with stripes on its wings that breaks into a hopping frenzy each night. Stripewings will fold themselves into compact shapes. They can often be seen, in massive colonies, sleeping on the surface of the Amoebic Sea.
- Symet - Symets are bipedal herbivores named for their protective symmetry. In Expedition, Barlowe observes a herd of Symets in a desert in bordering the Vallis Przewalski. The symmetry may have evolved to confuse predators. Image of a Symet.
- Thornback - The Thornback is an herbivore that walks on its three-legged gait. It has a large "thorn" on its back shaped like a shark fin. Image of a Thornback, Thornbacks pursued by an Arrowtongue.
- Tiger-bull - One of the creatures around the water hole. An orangish-brown striped animal.
- Transalpine Floater - A gray floater that resides in the mountains.
- Trunk-sucker* - The Trunksucker is a small animal that glides through Darwin IV's forests and clings to Plaque Bark Trees, sucking their sap. The first dead creature that the probes find on Darwin IV is in fact a Trunksucker, most likely killed by a Daggerwrist. Image of a Trunksucker from Alien Planet.
- Tundra-Plow - An animal that digs part of its body in the ground. It gets food from its underground proboscis, pulling plants from underneath as well as filtering soil for food.
- Tundra-Roamers - Animals that have a male and female variants. Males have a crest on the back of their heads.
- Tundra-Slider - An animal that resembles the Arctic Sedge-Slider with a few different variants.
- Unth* - The Unth is a tundra creature with asymmetrical tusks. Unths are named for the sound they make when they take a step. Unths live in herds. The Unths of Alien Planet are first encountered by Leo, but Ike meets up with this peaceful herbivore near the end of his journey. The Unth herd was apparently spooked by either the Bladderhorn duel nearby, or the mystery creature (which turned out to be an Eosapien), which deactivated Leo. Two Unths fighting in a snowstorm, a sketch of an Unth. In Expedition, Unths had only one gender but still fought for mating rights. In Alien Planet, the genders of the unths were unknown.
- Unnamed Flyer - This species has no common name yet. This flying creature is the main food source of the Prismalope in the northern plains. This species has developed an intriguing relationship with the Butchertree. Within a 15 ft (4.6 m) or so radius of a Butchertree are a dozen or so small growths. The growths are actually part of the Butchertree, connected to it by underground tentacles. These growths are physically identical in appearance to the small unnamed flyers and are used to lure the Prismalopes and other prey. This camouflage is also able to deceive prey into coming inside the Butchertree's attack range, where they then find themselves skewered and drained of fluids. Two Prismalopes unwittingly getting too close to a large Butchertree while investigating unnamed flyers (or the Butchertree's decoys).
- Wedgehead - One of the creatures around the water hole, the blue one which may have the same kind of symmetry of the littoralope
In his Expedition, Barlowe clearly states that he wanted to represent the most impressive, most appealing animals of the planet. There are millions of species who are not represented in detail, even though they have to be an essential part of Darwin IV's ecosystem. Barlowe refers to them as the 'microflyers', tiny animals and plants living in the atmosphere of the planet like plankton lives in the oceans of Earth. Most animals represented in both the book and the movie belong to one of two essential groups: the floaters and the ground-dwelling species. However, there is a great variety inside the landdweller family. While on Earth animals are classified by characteristics such as mode of reproduction and metabolism, the large Darwinian animals are classified by their number of limbs. There are four classes: quadrupedalians, tripedalians, bipedalians and monopedalians. However, sometimes it is difficult to say to which group an animal belongs. In fact many animals lose some of their limbs when they grow up, and thus "change" their classification. The forest slider, for instance, has four legs as a juvenile, but only two legs in its adult form. Most Floaters appear to have no limbs, but eosapiens seem to have evolved from bipedal ancestors for they still have two arms. However, these could as well be highly evolved appendages. Many unnamed creatures appear only in sketches.
- Aerophyte - Microscopic vegetative organisms that float on Darwin IV's air currents and constitute a major source of food for several species on the planet.
- Arctic Polar-vane A red plant that lives in the tundra. It rotates, feeding of the energy generated by the two suns.
- Beachfinger - These are grass-like plants that thrive near the Amoebic Sea.
- Blue whipweed - a plant that lives in the polar regions of Darwin IV
- Cliff-polyp - These are red grass like plants that are only eaten by Springwings and Bladderhorns.
- Darwin Moss* - These are the plants that are usually seen in grasslands. They resemble green moss on Earth.
- Darwin Tomato* - Darwin Tomatoes are giant molds that grow in the pocket forests. They can grow to be three feet tall.
- Electrophyte* - These red, mushroom-like plants electrocute animals that stray into their fields, and then consume them alive.
- Float Ball - These are bushes with stems so small they look like they're floating.
- Fodderball Weed - The Fodderball Weed produces football-like fruits called zimns. These weeds have a lightweight construction that puts them at the mercy of every wind.
- Gourd Tree/Steeple Gourd* -15-story tall plants that are supported by root-like stilts. Gourd Trees are either hollow or spongy inside. They have to be for the stilts to support them. In Alien Planet they are encountered by Leo and Ike, comprising the trees surround the landing site of the probes. In Expedition, the Gourd Trees are called Steeple Gourds. A couple of Gourd Trees (see left in image).
- Grenade Vine - a plant with explosive pollen sacks.
- Hillvine - Hillvines are long plants that grow in the hills.
- Jelly-bladder Plant - These are plants with jelly-like forms on their stems. The Gelsuckers eat these.
- Plaque-bark Tree* - These trees are tall with straight trunks, regular side branches, and sparse leaves. The Trunk Suckers feed on them. Daggerwrists can often be found clinging to the branches.
- Polardots - A plant with small blue flowers that lives in the polar regions of Darwin IV
- Red Mountain-spike - These are spiked plants that are eaten by Bladderhorns. They grow in mountain streams.
- Snow-bulb - Snow-bulbs are large white bulbs that live in Darwin IV's icecaps.
- Stickball Plant* - The Stickball Plant is part sponge and part virus. The only creatures that eat them are the Gyrosprinters.
- Tube Grass* - Long grass which is hollow like a tube giving the plant its name. It is striped.
- Yma - A benevolent race of extraterrestrials that are assisting the human race in rebuilding their damaged planet and began the Expedition to Darwin IV.
- Dr. Ysud - A Yma xenobiologist killed during a sudden ice storm.
- Dr. Ysire - A Yma xenobiologist killed along with Ysud in an ice storm.
- Wayne Barlowe - The main character and narrator, a wildlife artist.
- Dr. Dorothea Kay - The Expedition's chief botanist, she theorized that Darwin IV had once been warmer and more humid.
- Dr. Evan Tenbroeck - The Geological Survey Team's Head. He was known to be an unexcitable person, but was enthralled by the Flipsticks.
- Dr. Vinogradov - A geologist who pointed Barlowe in the direction of discovering the Grove-back.
- Video-Audio Pod - A device that records movies
- Hovercone - The Expedition members use this to fly around and explore