Introduction to Extant Fauna

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Sagan 4 is home to many groups of fauna (or, more broadly, what may be called "animals") both living and extinct, and for a newcomer just starting to explore its diverse array of biota, knowing where to start can be difficult. This guide serves to introduce each major group of living fauna on Sagan 4.

To browse through all extant organisms, use the species search engine or try digging through the ecosystem pages.

For the kinds of creatures that did not make it to modern times, see the Introduction to Extinct Fauna.

Krakowpedes

Krakowpedes are a group of superficially annelid-like fauna characterized by having multiple pairs of legs and a usually worm-like shape. Most krakowpedes are ancestrally blind, typically tasting or feeling the environment, but a few clades later developed eyes.

Interestingly, they are an outgroup of the purple flora, as they all descended from a species of purple algae that incorportated heterotrophic endosymbionts, allowing them to forgo photosynthesis in favor of deriving energy from other organisms. Krakowpedes are also referred to as "anipedes" or "segmentocaudans".

Trappers

Splitting from the krakowpede tree before the anipedes and centifins, the trappers are a relatively obscure group of exclusively marine worm-like fauna with multipartite jaws. Excepting the aberrant early-offshoot jetters, most taxa are sessile or slow-moving predators, either buried in the substrate or simply hidden in plain sight, snapping at prey when they least suspect it. As for the jetters, they take the niche of far more active pursuit predators, complete with jet propulsion organs and two sets of jaws: the main ancestral jaws, and a unique jaw-tipped trunk.

Centifins

Centifins are an ancient group of krakowpedes. While the earliest species could be recognized by their multiple limbs, long and slender forms, as well as the precursor exoskeleton. Many modern centifins have further evolved this exoskeleton and now possess three ocular organs as well. These descendants take on a variety of roles such small scavengers as well as larger mesopredators, and possess clear body segmentation - such as a distinct head region - and reduced number of limbs. Others maintain are more serpentine body plan much like their distant ancestors, though possess complex jaws for snaring prey and lack limbs for locomotion entirely. While the group was originally aquatic, most of the group's living descendants are terrestrial, having managed to adapt to dry land via earlier colonization in moist, warm regions such as rainforests.

True Anipedes

While all krakowpedes can informally be called "anipedes", only one class can be called true anipedes. These superficially crustacean-like fauna possess beak-like jaws and multiple pairs of specialized limbs - from walking legs, to antennae, to pincers, to paddling pleopods. In some clades however, the walking legs are reduced. Most true anipedes are small in size, and take up niches as plankton or in the benthos, however a select few taxa have achieved larger sizes, and have even left the waters behind.

Plents

Main article: Plent

Plents have historically made up a significant portion of Sagan 4's biota. A sort of "planimal", many species are both motile and capable of photosynthesis using a pair of large, mobile leaves. Many species have repurposed their leaves for swimming, flight, or thermoregulation, with or without retaining photosynthesis, while some have lost them completely.

Sea Plents

Sea plents are a highly diverse group of plents, coming in a myriad of forms, lifestyles, and sizes. Despite the name, several different lineages have independently attempted to colonize the land, with varying degrees of success. From the microscopic to the titanic, sea plents have proven to be incredibly successful and broad group, forming nearly all ladders in the aquatic food chains they make up at one time or another, though nowadays the vast majority of sea plents are on the smaller side of the scale. Planktonic blooms of both miniswarmers and microswarmers in particular provide food for a large variety of marine life, and help to support populations of gilltails, snarks, and other aquatic predators. While primarily free-swimming, some have evolved both sessile and benthic lifestyles in order to exploit new niches and avoid competition with their many evolutionary rivals.

Shockers

Main article: Shockers

Shockers are the most basal of the modern sea plents, possessing relatively fish-like bodies and electrifying jaws. Though they are not the predominant swimmers in Sagan 4's oceans, they have carved out a place for themselves and even have some semi-terrestrial variants.

Swarmers

Main article: Swarmers

Swarmers are the most numerous and diverse of the sea plents. Aside from the shockers, all modern sea plents descend from this group. Some species are somewhat fish-like, while others are microscopic and borderline sessile, fulfilling the role of phytoplankton. They also have several distinct subgroups diverging from these norms.

Skuniks

Main article: Land Swarmers

Unlike most sea plents, modern skuniks are terrestrial and walk on 6 legs usually supported by an exoskeleton. They are also among the few major groups of plents to have a through gut, rather than a blind gut.

Scooters

Scooters are largely amphibious swarmers that can sometimes be likened to strange, one-eyed frogs. They also take on pelagic forms which returned to the sea.

Plyents

Main article: Plyents

Plyents are terrestrial sea plents which behave like plants...almost. Unlike the extinct tree plents, many plyents retain the ability to move around and truly toe the line between plant and animal. Some of them closely resemble basal plents, while others are more plant-like with traditional leaves, wood, bark, and even roots. A handful of species are cursorial.

Plyents are technically a kind of swarmer which sits on its many tails with its mouth facing upwards.

Scuttlers

Scuttlers are benthic swarmers with cellulose-based exoskeletons. Most species have prominent beak-like jaws, which may be adapted for a variety of purposes.

Gregs

Gregs are a branch of swarmer which forms complex colonies of microscopic individuals that appear and function as just one, much larger organism.

Walking Plents

Walking plents are, surprisingly, a sister group to the sea plents rather than a clade within them. Walking upon four legs supported by flexible "wooden bones", walking plents have historically constituted much of Sagan 4's megafauna.

No-Plents

No-plents are the earliest-diverging major group of chloropods characterized by a superficially mammal-like profile and, in some species, an extra pair of eyes. Most modern species are fairly small and herbivorous.

Nodents

Main article: Nodent

Nodents are a subgroup of no-plents characterized by their prominent incisors and the separation of tail and butt nostril. They are the only no-plents to retain four true eyes.

Extant nodents are divided into the classic nodents (which have a distinctly mouse- or rat-like appearance), undis (which are small and often eusocial and have highly mobile incisors), neonodents (which resemble classic nodents but have beaked jaws), and tuskents (secondarily terrestrial, formerly domesticated nodents which walk on hands modified into whole limbs).

Ketters

Main article: Ketters

Ketters are an odd, generally toothless line of no-plents with fused leaves and long tail-like butt nostrils, which adapted their hind eyes into scenting organs.

Nobits

Main article: Nobits

Nobits are fairly anatomically basal no-plents which are warm-blooded. Most modern species sport inflatable vocal organs on their rears, which are used for honking.

Pterophytes

Main article: Pterophyte

Pterophytes, also called flying plents, are among the few modern walking plents to mostly retain large, functional leaves, not because they are dependent on photosynthesis, but because they use them to fly. Incredibly diverse, flying plents make up a significant portion of all plents living or extinct and feed on a myriad of different food sources.

Phlyers

Main article: Phlyers

Most modern species of flying plent are specifically phlyers, which are found on most landmasses and are also the only living group to actually retain flight, at least for the most part. They have beaks, and they steer using an airplane-like tail.

Sprinters

Main article: Sprinter

The sprinters are close relatives of phlyers which cannot fly. They actually lost flight a few times independently, as the first sprinters actually were capable of flight, somewhat akin to Earth's ratites. Most sprinters lack wings or have modified them beyond recognition, such as the case of hikahoes using their wings as pouches to carry their young. Some species still have front legs and a few are even quadrupeds, but they are by and large a bipedal group.

Bandersnatches

Main article: Bandersnatches

Bandersnatches are another flightless group of pterophytes, which have barbels which may be hardened into fangs and have a distinctive crest or sail upon their heads. Many modern species have unique sexual dimorphism wherein males are quadrupeds while females are bipeds.

Bearhogs

Main article: Bearhog

Relatively basal in anatomy as far as modern plents go, bearhogs also retain their leaves. Most living species are herbivorous and live in Wallace or Kosemen. Despite their appearance, bearhogs are not closely related to the no-plents, having developed a mammalian profile independently. In fact, the closest living relatives to the bearhogs are the gulpers.

Gulpers

Main article: Gulper

Gulpers are among the more derived plents, lacking leaves or front limbs and having spider-like fangs and long prehensile tongues. This bizarre appearance means that at a casual glance, one might not even recognize them as plents. Most modern species have armored heads and can zap predators or prey with an electric tongue. They can be found on all landmasses, but most of their diversity is in Wallace and Drake.

Worms

Main article: Worm

Contrary to their name, worms are some of the most complex fauna on Sagan 4. An ancient symbiosis of animal- and plant-like cells, worms are known for their two distinct cell lines, the fleshy "red cells" which make up most of their flesh and the rigid "green cells" which have cell walls and originally formed a living exoskeleton. To distinguish them from other worm-like fauna on Sagan 4, this group is sometimes also referred to as "binucleid worms".

Beakworms

Main article: Beakworm

Beakworms make up most of Sagan 4's "fish". A unique branch of their own, they have the most reduced green tissue of all the worm groups. Some prominent kinds of beakworm are gilltails and gillfins, both of which can be found all over Sagan 4's oceans.

Bubblehorns

Main article: Bubblehorn

Bubblehorns somewhat resemble many-legged molluscs with prominent sensory "horns".

Murkworms

Main article: Murkworms

The secondarily aquatic murkworms were once very diverse, but are now restricted to just a few filter-feeding species. They are the closest living relatives to the Saucebacks and are found in Wallace, Kosemen, and Fermi.

Saucebacks

Main article: Saucebacks

Saucebacks look out of place among other worms, with their feathered bodies and single pair of legs making them somewhat resemble dinosaurs, if one ignores their mammalish ears and insect-like jaws. Unlike their cousins, saucebacks have a primarily internal skeleton which allows them to reach great sizes. The earliest saucebacks, and many modern species to this day, lack eyes and instead navigate their world using echolocation.

Saucebacks are very diverse and are found on every landmass. Some major types of saucebacks include:

Waxfaces, which are found in Barlowe and along coastlines
Larvabacks, which are aquatic and found in most waterways
Loafshells, which have segmented shells and are found on Drake
Shrewbacks, which are small and shrew-like and found on most landmasses

Ornitheres

Main article: Ornithere

Ornitheres are a particular subgroup of saucebacks which resemble birds and bird-like dinosaurs. Though a very young group, they have been diversifying rapidly, taking on forms ranging from tiny quail-like creatures and arboreal foragers to megafaunal carnivores and giant azhdarchid-like piscivores. They are the most prominent of the eyed saucebacks, having a unique eye structure called an eyestril which is capable of both seeing and smelling.

Scuttlecrabs

Main article: Scuttlecrabs

These surprisingly close cousins of saucebacks and murkworms resemble ordinarily arthropods, but often have leathery skin covering their exoskeleton. In modern times, scuttlecrabs consist of the Kruggs (which are global), the Korrybugs they descend from (which are found along polar and subpolar coastlines), and the Crystank Walkers (found in Drake).

Lizardworms

Main article: Lizardworms

Lizardworms are a subgroup of scuttlecrabs which, as their name suggests, resemble reptiles. They also have an endoskeleton and can get fairly large. Among them are the fairyshells of Barlowe, which have four legs and long sensory limbs, and the gossalizards, which can produce silk, have eight legs (or 6 legs and 2 arms), and come in both cold-blooded reptile-bug varieties in Barlowe and fuzzy lukewarm-blooded and even fully warm-blooded varieties in Drake.

Wingworms

Main article: Wingworms

Wingworms are Sagan 4's closest analog to flying insects and are very diverse, being found on every landmass. They evolved from 12-winged, many-legged ancestors with many eyes on their backs, but the status and number of all of these vastly varies across the many living groups.

Carpozoans

Marephasmatises

The radially symmetric jelly-like carpozoans are, in the modern day, represented only by the stinging rainbow marephasmatises. These are the most basal and ancient of all living carpozoans.

Filtersquids

The closest relatives to modern marephasmatises, filtersquids generally resemble cephalopods in appearance, albeit very superficially.

Spondylozoans

Spondylozoans are the vertebrate-like side of carpozoa which bear an internal skeleton and constitute some of Sagan 4's megafauna. Though similar to Terran vertebrates, they commonly have 6 eyes, and terrestrial forms have unusual shoulder-like hip anatomy.

Snarks

Main article: Snarks

Resembling fish with nasal gills, snarks form a considerable portion of Sagan 4's oceanic megafauna. Most modern snarks are scylarians, which have just one pair of flippers.

Anisoscelidans

Anisoscelidans are a branch of spondylozoans who colonized the land, containing the caudopods, snappers, and limblesses. This group contains all living spondylozoans who aren't snarks.

Pentapodes

Pentapodes are a terrestrial branch of anisoscelidans which are named for their ancestral locomotion which involved walking on the tail as a fifth limb. Originally the reptile-like grade to snappers' amphibia, today they are represented mostly by therapsid-like forms.

Dwellers

Main article: Dweller

Nearly all modern dwellers consist of the pentapedal glasseaters and the tripodal grubnubs, respectively bearing goat- and bat-like faces and prominent ear-crests. Most members of this group are herbivorous, often eating tough vegetation.

Shrews

Main article: Shrew

Shrews are very mammal-like pentapodes which, unlike the dwellers, no longer walk on their tails. They can be distinguished from most other terrestrial anisoscelidans by their mammal-like faces, and from the (relatively) closely related dwellers by their retention of all 6 eyes. They come in two broad varieties, the highly mammalian furred shrews and the more reptile-like blood shrews (bubbleskins and soriparasites). Shrews are the only pentapodes to have developed protruding femur-like hind shoulders, an adaptation which is otherwise only found in tetrapodes, and they did so several times independently.

Furred shrews are split into tams, which are typically armored; neoshrews, a subgroup of tams which lack armor and look more like regular mammals; cheekhorns, which have exactly what their name suggests; and shroots, which are more ancient and have a more primitive hip structure. Also among the tams are a noteworthy subgroup, the tamjacks, which are major ecosystem engineers thanks to their saw-like tails and remarkable construction instincts.

Capis

Main article: Capis

Capis are an odd, rare branch of foreleg-bipedal pentapodes which retain certain basal characteristics such as chromatophores, which were lost in other groups. Capis are the least therapsid-like of the living caudopods, for having lost their lips in favor of a beak.

Tetrapodes

Tetrapodes are the branch of anisoscelida which originally walked on four legs, rather than five. The majority of species are considered snappers.

Skysnappers

Main article: Skysnappers

Skysnappers are warm-blooded, bird-like snappers with hollow bones and membranous wings. Although the vast majority of taxa within this group are predatory, skysnappers do contain taxa that have gone into other kinds of diets, with some even being herbivorous. Most members of the group as also strict bipeds when on the ground, though some have become quadrapeds over the course of the group's history.

Turtsnappers

Main article: Turtsnappers

Turtsnappers, as their name suggests, are descended from turtle-like creatures. However, many have reduced armor and instead fill the role of various kinds of reptiles and amphibians, with some even become more like fish. Despite their reptilian appearance, the majority of turtsnappers must lay their eggs in water. They constitute a significant portion of Sagan 4's current megafauna.

Earbacks

Main article: Earbacks

Earbacks are an ancient, rare line of snappers who, as their name suggests, possess a row of ears that run down their backs. Modern representatives are descended from blind cave-dwelling species.

Limblesses

Main article: Limblesses

While they are closer related to the snappers than they are to any other group of spondylozoan, limblesses are a distinct group in their own right. Lacking limbs, limblesses typically fill ecological roles similar to snakes, with the vast majority taxa being carnivorous. Despite this, there are some species that have become omnivorous or even herbivorous. Most limblesses are fully terrestrial, typically burrowing underground or slithering on the surface. There are exceptions to this rule, however, with a few species being semiaquatic or arboreal, with the seaswimmers having even become fully aquatic.

Ukfauna

Main article: Ukfauna

Ukfauna are relatives of plents which usually have 2-4 limbs surrounding their mouths.

Marfinns

Marfinns are an ancient group of ukfauna, one that is actually more closely related to the long extinct crymaids than they are to any other group of extant ukfauna. Marfinns are characterized by possessing 2 tentacles, a finned tail, and a single large tooth. Although relatively low in overall diversity, marfinns are quite widespread, being found all over the ocean.

Urchips

Urchips are by far the most diverse group of extant ukfauna, with many groups having evolved very different bodyplans from one another. Despite this, they do have some shared characteristics, with urchips usually having 4 limbs and a shell, they also may or may not have a toothed mouth. Most of them are aquatic, but the uktanks, found mostly around Lamarck, Drake, and Ramul (with the exception of the more widespread shailnitors), are terrestrial.

Colonial Uksips

Colonial uksips are various social, burrowing ukfauna which have four arms and long teeth adapted for digging.

Swamp Hunters

Swamp hunters aquatic ukfauna related to ukbacks.

Ukbacks

Ukbacks are terrestrial or semi-aquatic, generally bipedal, and have clawed arms and a proboscis-like tooth. Larger species are found mostly in Wallace, while smaller ones are global.

Beans

Beans are various simple sessile filter-feeding creatures which resemble sponges. Some more derived species have anemone-like traits.

Iron Fauna

Main article: General (Siderobiota)#Fauna

Iron fauna are magnetic creatures which metabolize dietary iron as part of their respiration. Iron fauna typically resemble arthropods or worms in general appearance. Most species are found in Barlowe and Lamarck, but blood-sucking species can be found everywhere.

Whorls

The whorls are primitive, radially symmetric cousins of ukfauna with long tails and other trailing structures. Although a few species have become predatory, the vast majority of whorls are filter feeders.

Fee

Fee (singular: foi) are unique among Sagan 4's fauna in that they consist only of a single, highly complex cell. They're generally aquatic, and many of them resemble some kind of translucent slug or flatworm.

Charybs

Charybs are distinguished from other fee due to their multicellular nature. All current extant species are descended from charybdis, and on average tend to possess a lifecycle involving multiple distinct stages as well as sexual dimorphism. At least one lineage has developed a symbiotic relationship with photosynthetic organisms which grow within specialized nodules on branch-like extensions off their main body.

Tristages

Tristages are various simple, shelled creatures that generally resemble mollusks in appearance. While almost all members of this group are strictly aquatic, a branch native to Drake known as the clamguses have become terrestrial, though they still need to remain in damp environments to avoid drying out.

Rorms

Main article: Rorm

Typical Rorms

Armored Rorms

Armored rorms are a group of rorms that would develop armored bodies for protection. Although arrowheads technically derive from this group, they are distinct enough to form a grouping of their own. As such the only living armored rorms that can still be considered part of the group are the pukais. Pukais are highly derived, lacking fins and ironically enough having reduced shells. They are sessile or free-floating filter-feeders.

Arrowheads

Gillrorms

Kelpoggles