Introduction to Extant Fauna
- This page is under construction.
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.
For the kinds of creatures that did not make it to modern times, see the Introduction to Extinct Fauna.
KrakowpedesKrakowpedes 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".
TrappersSplitting 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.
CentifinsCentifins 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 AnipedesWhile 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.
- 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 PlentsSea 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.
- Main article: Shockers
- Main article: Swarmers
- Main article: Land Swarmers
ScootersScooters 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.
- Main article: Plyents
Plyents are technically a kind of swarmer which sits on its many tails with its mouth facing upwards.
ScuttlersScuttlers are benthic swarmers with cellulose-based exoskeletons.
GregsGregs are a branch of swarmer which forms complex colonies of microscopic individuals that appear and function as just one, much larger organism.
Walking PlentsWalking 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-PlentsNo-plents are the earliest-diverging major group of walking plents characterized by a superficially mammal-like profile and, in some species, an extra pair of eyes. Most modern species are fairly small and herbivorous. Living types of no-plent include nodents (found mostly in Wallace, Koseman, and Drake), ketters, and nobits (found in Wallace and Barlowe).
- Main article: Pterophyte
Most modern species of flying plent are specifically phlyers, which are found on most landmasses and are also the only living group to retain flight. Related to them are the emulsechoes (found in Barlowe), the sprinters, and the bandersnatches, which each lost flight independently.
- Main article: Bearhog
- Main article: Gulper
- 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".
- Main article: Beakworm
- Main article: Bubblehorn
- Main article: Murkworms
- Main article: Saucebacks
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
- Main article: Ornithere
- Main article: Scuttlecrabs
- Main article: Lizardworms
- Main article: Wingworms
MarephasmatisesThe 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.
The closest relatives to modern marephasmatises, filtersquids generally resemble cephalopods in appearance.
SpondylozoansSpondylozoans 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.
- Main article: Snarks
Caudopods are a terrestrial branch of spondylozoa which are named for their ancestral locomotion which involved walking on the tail. Originally the reptile-like grade to snappers' amphibia, today they are represented mostly by therapsid-like forms.
- Main article: Dweller
- Main article: Shrew
- Main article: Capis
Snappers form most of the reptile- and amphibian-like spondylozoans.
- Main article: Skysnappers
- Main article: Turtsnappers
- Main article: Earbacks
- Main article: Limblesses
- Main article: Ukfauna
MarfinnsMarfinns 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.
UrchipsUrchips 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 UksipsColonial uksips are various social, burrowing ukfauna which have four arms and long teeth adapted for digging.
UkbacksUkbacks 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.
BeansBeans are various simple sessile filter-feeding creatures which resemble sponges. Some more derived species have anemone-like traits.
- Main article: General (Magneferrubiota)#Fauna
WhorlsThe 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.
FeeFee (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.
CharybsCharybs 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.
TristagesTristages 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.
- Main article: Rorm
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.