#pentapods

First off, the lung is located right against the shell atop the back and is about the same length as the bone girdle that supports the other organs and leg anchors. The lungs basic structure has two bone pieces at either end, a 'nozzle' which holds open the airway, and the 'butt' which just helps maintain structure. The main support comes from four rings of cartilage, which prevent the lung from fully sucking closed on exhale! This is because the lung is open and closed by way of tendon! Four main tendons are anchored to the girdle and bottom wall of lung, the muscles associated with these tendon contract to pull open the lung and draw in air. Running through the lung itself are smaller tendons also connected to that bottom wall. These anchor to the shell and pull upwards to push air out of the lungs. While both sets are able to fight against the other, the lower tendons have a lot more tension and so the 'default' position of the lung is open.

But for Whorls, breathing is a pretty much involuntary process, think how you can choose to hold your breath but most times don't even think about needing to manually breathe. Aside from right now! At least they don't have to worry about manual blinking, could you imagine?

The eco system these guys inhabit are the vast shallow sea beds between the sea and 'land'. Where the microbial mat swells up to take in sunshine whilst keeping somewhere between a few inches to a foot of water above. This habitat favors walking over swimming for larger beasts, doing a separate post for the 'fish' of Backera. Those are a whole other brand of beast. For now we'll stick to the larger animals on the scene. Going left to right because I'm biased. 1. A quad-pod, a fellow who specializes in using mouth parts modified into clubs to break into shells and rigid 'plants'. While they have two very LARGE jaws, the other three are teeny tiny so they mostly rely on suction once they open their food. They have decided to be boring and use only their front four legs for walking, whilst their hind leg is to scrape out divots to lay eggs in the sea bed. 2. A TRUE pentapod, these guys spend their day swishing their heads back and forth. The wide arc of their eyes allow them to always have a lot of vision above the waterline at all times. Their dainty mouthparts are a constant scuttle against the slime mat to kick up organic matter to scarf down. The long horn jutting up their back is actually hollow and used to trumpet at each other at a distance. Very noisy. 3. With the least amount of feet in the lineup is the flag foot! These fellas are built to prance through the water and chase down any poor fish spotted by those big ole peepers. But they really shine when it comes to display. Upon meeting, the smaller individual will lower their head and wave around their display legs, wooing their potential partner with flashes of color. Most of the time their audience ends up wandering away.

Whorls are a sophont from the slime ball planet Backera, the planets crust is entirely covered in miles thick microbial mat so the floor is always very much alive. The main form of "animal" life on the planet are the pentapods, analogous to Earth tetrapods in terms of niches and all that. Pentapods are distinguished by their five limbs, five jaws, partial exoskeleton, and an internal boney limb girdle. Whorls are from a clade of predatory pentapods who branched into frugivory a while back, eventually leading to tighter knit communities built around maintaining their farm mats. Whorls live in towns with populations between a few dozen to a few thousand, their settlements are also how they get their name. Their buildings are spiral shaped, expanded by spiraling them outward! I'm getting around to drawing that, its v cool. They eat mostly 'plant' matter, fruiting bodies from sessile organisms and maybe some choice floor scrapings. Meat is also greatly enjoyed, but is typically reserved for older Whorls or very small children. Children who by the by, go through a little aquatic stage before committing to wet land. Babies are traditionally left to grow in slow moving rivers, but modern times find communal pools to be a lot more popular.

1. The world itself is a little smaller than Earth, but is also the third planet from it’s star and has two moons. It has a pretty even climate with no icecaps due to it’s very thick hothouse atmosphere, even despite it’s p crazy axial tilt. It’s atmosphere is similar to Earths but contains a lot more water vapor and methane and less nitrogen. The surface of the planet is covered almost entirely in microbial mat, to the point where actual ground is buried miles deep and the world would be entirely covered in ocean if not for the mats. The only ‘land’ comes from mounds of organic material built up from the sea floor that have grown large enough to finally breach the surface.  Names Planet: Backera  Bigger Moon: Milcer Smaller Moon: Daunverr Sun: Sentil 

As for the macrobiology I’m still working it out but right now there are two basic groupings of terrestrial pentapods. Subject to very likely change. 

First are the Eyebacks. Who are most known for uh, having eyes on their back. They also have their gills open on their neck and need to submerge time and again in water to breathe correctly.

2. That group includes this lil beastie, the Foxtrot, who lives up to their namesake being a crafty lil ankle biter. They are a fast lil critter who prowls the coast for small fast moving prey. They are also quite capable swimmers and swap between land and sea whenever they need to grab a snack or avoid becoming one. 

3. Another Eyeback is the aquatic Mynar, who uses their big ass nose horn to scrape away at the mats and stir up fresh food. Generally they stay in water only a few feet deep, moving on to find the freshest growth. Their life style leaves them with a coating of their own though, stained by the food they stir up. 

Second group are the now tripodial Elytra’s, who have badass lil beetle backs, and have lifted their front two limbs up to use for object manipulation. They are terrestrial but still rely on water for their tadpole larval stage. 

4. This is called a Thwap, because they are very aggressive and use those first set of limbs for smacking anything that makes them even slightly uncomfortable. These are predators that focus on terrorizing smaller prey, loosely associating in groups of 3-10 individuals.  

5. The SOPHONT!! I have no idea what to name these guys, so ideas are welcome! I just knew I wanted to give ‘em big ole eyes. They are a omnivorous people descended from hypercarnivorous ancestors. Their culture is centered around large families, usually a ‘wife’ and their many ‘husbands’, but the main thing to set them apart from the rest is the amount of care put into raising their offspring. They will have large pools dedicated to their lil babies until they’re ready to be walking around. Not super advanced technologically since y’know, iron and other metals is somewhat inaccessible. But maybe that’ll change, still thinking of how I want to set up the planet.