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I noticed that biat (interbiat descendants) are a fairly popular kind of organism to evolve and widespread, even yielding six species in a small genus group. To reduce the chances biats will not eventually ecologically overtake skysnappers entirely through their popularity, I have created a list of physiological advantages, disadvantages, and constraints between skysnappers and biats. This may be useful to put on the wiki as a meta page. I have posted it here for double-checking, feedback, and expansion as needed.

Skysnappers and Biats: A Comparison


Jaws and Mouthparts

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Interbiats’ jaws make it easier to snip and shear vertical structures (e.g., grass, vertically-oriented legs).

Picking up objects which are dorsoventrally (up and down) flattened and wide, like a pancake, may be tricky for biats.
• Consequences for Other Organisms: Prey organisms, such as those with crablike shapes, could develop spiky pancake shapes to deter biat predation.

Interbiats lack lips; regaining lips may necessitate reducing the size of the mandibles. In some species, their mouths are exposed to open air and prone to water loss.
Consequences: Snappers may have a slight advantage in some desert environments due to preventing water loss.

Biats have external jaws, much like an ant’s.
Consequences: As Interbiats’ jaws are external, food might fall out. Depending on the internal mouth anatomy, it may be difficult to impossible to chew the cud (like a hoatzin) or otherwise process it inside the mouth (e.g., with amylase in the saliva).
Consequences: Due to their mouth anatomy, it is difficult to evolve cheek pouches or throat pouches (like a pelican).

Snapper snouts might have multiple bones and ligaments to work with along its length.
• Biats can’t navigate holes or burrows with their mouthparts and flexibly pinch food in the tips of their jaws as certain foraging birds do.
o There’s a workaround for this by niche by using very long and narrow jaws, but they’d still have to stab food, and then get the food off their beaks somehow, rather than snapping it up.
 Consequences for Other Organisms: Organisms which are laterally-flattened, heavily armored, or both are harder to stab from above.
 Gelatinous organisms may be able to move their essential organs out of the way if stabbed with a glancing blow.
 Very slippery organisms (especially if they have some kind of slippery blood/internal secretion) may be able to slip off a biat’s long jaws, like a raw egg yolk off a fork.

Because biats’ “teeth” (cutting edges on their jaws) are part of the structure itself, they can’t be knocked out or dislodged. However, this also means their options for having different tooth shapes at different life stages for different prey is limited. If the prong wears out, they can’t grow a new one (although if it’s continuously-growing like rodent teeth, this is easily circumvented).

Limbs

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If a biat needs to move while holding something, it would probably need to hold the object inside its jaws or inside its body (e.g, mouth, digestive system) A snapper can use its jaws, its feet, and digestive system. Snappers may be able to fly with both a loaded snout and loaded feet.
Exception: Some kinds of small objects could be carried in its feathers, pinched between its hoofed toes, balanced on its back, curled underneath its tail, or stuffed in its ears (though this is less practical).

Because Biats use the same limbs for both walking and flight, modifications that improve functionality in one use may harm functionality in another. Skysnappers can have one set of limbs well-suited for one function while retaining flight (though bigger, heavier legs do tend to increase weight, hindering flight to some extent).
• For example, Skysnappers can have long, narrow, albatross-like wings without needing to make them structurally sound enough to stand on.

While many biats are good at climbing due to goat-like hooves, it may be difficult for them to climb up near-vertical surfaces with insufficient traction. This could be trees with smooth bark (especially during rain), smooth-walled caves, or moist clay embankments (like parrots eating clay on steep riverbanks).

Given their four limbs and (as an ancestral condition) wing claws, it’s a lot easier for skysnappers to evolve lifestyles which use low-profile quadruped movement or scampering.
(e.g., like a vampire bat sneaking up on a host on the ground, or like a New Zealand short-tailed bat)

Biats lack proper grasping feet, but can balance on rocks and branches with their hooves, like a goat.
Consequences: Biats can’t quickly come in from a landing onto a thin branch that would shake on impact, since they would be dislodged. Biats may lose their grip on branches in strong winds. Biats can’t grip slippery prey in their feet (e.g., as ospreys carry fish in their feet).
Caveat: One should note many skysnappers also lack gripping toes, although this is easier to evolve for them than for biats.

In addition to flight hindrances, the back-to-front structure of biats’ toes and hooves makes it difficult to develop webbed feet that allow for ducklike or puffinlike paddling. A different technique would be needed.

Since Interbiats’ legs are also their wings, they will (by default) be unable to fly or walk if one leg is broken. For larger species (which are generally heavier and would have a harder time hiding) it is effectively a death sentence unless it lives in a group that will take care of it while it heals. However, a skysnapper with a broken wing can still walk, and one with a broken leg may still be able to fly. If a predator breaks the leg of an Interbiat, it is very unlikely it will be able to escape, while Skysnappers may be more likely to escape.

As a physiological compromise, the hips are flexible to allow for use of the legs as wings. However, this means that a biat that can fly is likely to expend more energy just standing upright.
Consequences: Snappers may be more suitable as stand-and-wait predators, like herons, or like polar bears sitting by a hole waiting for a seal.

Since skysnappers’ wing claws are often nonessential to flight, they can be modified or lost readily, allowing for specialized niches. (e.g., aye-aye claws, club-claws, absurd decorative claws)

Interbiats have feathered wings, while snappers have wings of skin.
Consequences: Snappers’ uncovered wings may allow them to passively diffuse heat into the surrounding environment faster, giving them an advantage in hot environments. However, skin-covered wings are a disadvantage in cold environments for the same reason. (Note that there are workarounds: the Snowy Florasnapper has “blankets” of fluff-coated skin which covers its wings, and the Snowy Corvisnapper has feathered wings.)
Consequences: Wings of skin may also be useful in humid environments where panting or urinating on exposed skin (e.g., legs) for sweat-like evapotranspiration isn’t practical.

Their wing-supporting toes must be kept clear off the ground, so a bad fall could leave them incapable of flight. Bad falls are more likely in uneven, stony terrain or a terrain full of thornbushes which could snag on the wing toes.

Biats “pole-vault” into flight, as pterosaurs do. They therefore need to have launching ability in their leg-wings. (However, a workaround is climbing up high places and then falling.) They also need to launch themselves forward, and can’t launch themselves into the air straight up.
Consequences: They can’t (or may find difficult to) launch themselves from unstable or slippery surfaces (e.g., ice, loose sand).
Consequences: Needing to go forward for a while after launch may make be difficult to navigate in air where tight turns are immediately needed, such as in trees with especially dense branches or in brambles.

Senses

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Skysnappers’ nostrils are farther down the snout than a biat. A lifestyle of foraging in substrate based on smell, like a kiwi, is difficult for a biat to evolve.

Since biats breathe through their eyestrils, they can’t see underwater unless the eyeball is enclosed, meaning they must have specialized eyeballs.
• However, this is easy to work around, either by enclosing some eyeballs or using some other sense to navigate underwater. This may require expanding other nostrils’ size or increasing oxygen capacity or refill rate if in an oxygen-intensive niche.

Biats can echolocate, while skysnappers are deaf (or almost completely so).
Consequences: In completely lightless conditions, such as deep in caves, moonless nights, or deep within dense blackflora forests at night, skysnappers would be unable to use echolocation, eliminating the most practical workaround for high-speed flight. Biats therefore have an advantage in some nocturnal conditions.
Consequences: Biats’ echolocation relies on shape, not color or shading, meaning they can sneak up on prey which have camouflaged color but not shapes. They have a particular advantage over deaf prey (such as skysnappers).

Snappers could use their snouts as malleefowl do to check temperature in compost-nests. Biats would need to use either a different body part to check temperature or develop heat/oxygen sensors on the jaws themselves, which might be difficult to evolve.

Other

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Airborne sand, smoke particles, small fauna (e.g., flying insectoid fauna) or other airborne debris can impede interbiat’s vision and respiratory system simultaneously. To dislodge the debris, an interbiat would need to repeatedly shake its head around like a dog, while a snapper would not.
Consequences: Sandstorms, smoke from wildfires, tiny insectoid swarms, and high densities of spores or pollen (e.g., from blackflora trees) make sit-and-wait predation tactics less practical for interbiats than for snappers.
Consequences: Interbiats may nonetheless be able to navigate effectively in low-obstacle environments or if they can use echolocation. Snappers can close their eyes, but as they are deaf, they cannot echolocate.
Caveat: Though they still lack eyelids, it is possible to make some eyestrils sealed and function only as eyes (e.g., the Ascendophrey).

Biats generally lighter than a skysnapper of the same size, due to more extensive internal flight adaptations. For example, using the same limbs for both flight and walking saves on weight, which can give biats an advantage in flight.
• A niche like a swift would potentially be easier for a biat.

Biats, by default, have multiple pairs of lungs. This makes it much easier for them to evolve complex and unidirectional respiratory systems because they have multiple pairs of lungs. For skysnappers, evolving this trait would be uncommon and difficult.
Consequences: Biats, by default, have an advantage in lower-oxygen environments, such as high in the atmosphere, or when they need a lot of oxygen very quickly.

Snappers have a different center of gravity than interbiats, which may affect their lifestyles.

Biats use their ears as stabilizers and to generate lift.
Consequences: While useful, having large side-to-side ears keeps them from achieving a bullet-like shape of maximum aerodynamics, limiting their ability to take on certain lifestyles.

Pterosaurs actually could launch from water, so I see no reason biats can't. In fact, pole vaulting species will always be lighter in overall weight than things that can't. The leg strength problem is not only nonexistent, but with the existing lightweight traits of biats they can actually get larger than the biggest pterosaurs, in theory.

Biats have some respiratory advantages. It's much easier for them to evolve complex and unidirectional respiratory systems because they have multiple pairs of lungs, while for skysnappers evolving this trait would be uncommon and difficult. Earth tetrapods have done it before, but only a few times.

Skysnappers are inherently much heavier than a biat can be, as their only lightening adaptation is their hollow bones. Having separate legs and wings means they have to have two pairs of strong heavy limbs instead of one, much like birds, and on top of that their wings are membrane-based so they're heavy from all the water inside. Biats have dead dry lightweight feather wings, which not only need to be smaller than a skysnapper wing to carry the same weight but also weigh less overall. Same with all their other flight surfaces such as the ears and tail.

All this said, there's no reason for these groups to be unable to niche partition. Flying isn't a niche, it's a method.

QUOTE (Disgustedorite @ Dec 27 2022, 08:56 PM)

Pterosaurs actually could launch from water, so I see no reason biats can't. In fact, pole vaulting species will always be lighter in overall weight than things that can't. The leg strength problem is not only nonexistent, but with the existing lightweight traits of biats they can actually get larger than the biggest pterosaurs, in theory. Biats have some respiratory advantages. It's much easier for them to evolve complex and unidirectional respiratory systems because they have multiple pairs of lungs, while for skysnappers evolving this trait would be uncommon and difficult. Earth tetrapods have done it before, but only a few times. Skysnappers are inherently much heavier than a biat can be, as their only lightening adaptation is their hollow bones. Having separate legs and wings means they have to have two pairs of strong heavy limbs instead of one, much like birds, and on top of that their wings are membrane-based so they're heavy from all the water inside. Biats have dead dry lightweight feather wings, which not only need to be smaller than a skysnapper wing to carry the same weight but also weigh less overall. Same with all their other flight surfaces such as the ears and tail. All this said, there's no reason for these groups to be unable to niche partition. Flying isn't a niche, it's a method.

QUOTE

Pterosaurs actually could launch from water, so I see no reason biats can't.

I checked that. Apparently, that is new knowledge. I will update the list accordingly.

I'm aware of the possibility of niche partitioning. Opportunities for niche partitioning are implied in the list.

I noticed that your response exclusively points out negatory things: that is, it's both negative in tone and provides no favorable concessions or admissions for skysnappers. In fact, almost all of your response seems to suggest, in detail, how biats are inherently superior flying organisms. To point out the utility of the list and provide additive feedback as well would be more constructive.

being inherently heavier, and not needing to waterproof, could make skysnappers more suited to diving and being aquatic in general (though chitin doesn't need as much waterproofing as keratin tmu)

Biats probably wouldn't be very good waders even if a compromise is found for the hip issue. Having wings on their legs means they would have to have long toes, which they then stand on the tips of, to keep the feathers clear of the water. The long toes, in turn, would interfere with flight.

QUOTE (Coolsteph @ Dec 28 2022, 03:19 AM)

I noticed that your response exclusively points out negatory things: that is, it's both negative in tone and provides no favorable concessions or admissions for skysnappers.

It's an understandable bias, one I bet all creators can relate too. At the risk of going against that bias and shooting a few of my own sagan children in the wing-legs...
https://www.youtube.com/watch?v=ALziqtuLxBQ

pterosaurs relied on their hindlimbs, so how did bipedal pole-vault launching go through without anyone demanding so much as a sketch (Asking for a friend who had to learn CAD just to demonstrate basic biomechanics... Twice over so far)? Not to mention doing so from branches with hooves. Just watch how cautious goats need to be when climbing and how carefully they angle their foot just right to catch the corner of the foothold between the hooves, and imagine having to be just as careful with and calculating where you step while having to build up speed (though echolocation could be key to that). Don't get me wrong, I believe it can be done, but we can't be certain and I definitely haven't seen anyone put in the work to demonstrate it or explore it, and that's a whole can of worms of potential consequences and implications that I haven't seen explored at all and could very well bring about a more grounded comparison between these lineages, if not an outright grounding one.

Additionally, from this thread it appears clear there is lack of avalible information about the ophrey respiration system, which make it difficult to discern potential disadvantages and weaknesses it might have, and that's another area that has the potential to bring about a more thorough comparison with skysnappers.

This post has been edited by Jarlaxle: Jan 16 2023, 04:04 PM

I've added more information, and sorted each by subject. I wasn't sure if biats had tongues, so I didn't add tongue-specific information.

The ophrey respiration thing was just a matter of Colddigger not reading the description and musing an incorrect elaboration. It's clearly described in the text.

Biats do have tongues, all saucebacks do. It's how they chirp.

So they have separate intakes and exhaust spiracles and 4 lungs but are not "intestine-like" (in terms of through gut?) because their unidirectional lungs use air sacks like birds rather than a through passage between the lung pairs which would mean CO2 reaches the exhaust spiracles by individual molecules going on a heroes journey through a portal to Narnia in a closet hidden in the first pair of lungs as long as the witch doesn't cause sneezing.

Yep, that doesn't need any visual clarification at all.

That said, other than being told their ancestry is comparable to vertebrates but deaf with 3 eyes, sky snappers' internals are even more of a mystery. How do we know what respiratory solutions did they adapt for flight? Having a vertebrate-like respiratory system hasn't stopped birds from evolving a very bird-like respiratory system. If the creators are willing, there is plenty of room to fill in the blanks and figure out what internal systems might have developed through millions of years of flying.

One thing that comes to mind is the bird-like pose. Do they have a keel?

The intestine-like descriptor is wrong because it implies the internal structure looks like an intestine. The structure is actually like, well, a lung, just segmented, lobed with air sacs like a bird, and with separate intake and outtake.

"So like, a house, with rooms, and walls, and a front door and a backdoor"
- if you gave that to a 100 architects, do you think you'll see the same layout twice?

No, but it gives you enough of an idea of how it works that whether it does so shouldn't be in question.

And yet someone designing it with a corridor is a misinterpretation? How is that not a plausible interpretation of that description?

Or through a lens more relevant to the topic, beyond the importance of understanding the scope of plausible interpretations and placing the onus on the artist, the reality is that any layout you choose would have different advantages and disadvantages. By obscuring the design with what is essentially "plot armor" in the ongoing story of Sagan, you prevent reasonable scrutiny. Which could be fine under some circumstances (such as when all sides regard the details of the system with a degree of abstractions), but is it reasonable when you are the one making the comparison by actively holding that system as an advantage?

Wouldn’t you prefer it if the defense of your work was more than barely one stepped removed from "my lineage can beat your lineage because of its super-efficient lungs!" while listing "super lungs" as the respiration type?

This post has been edited by Jarlaxle: Jan 17 2023, 02:42 PM

IMO though bipedal pole-vaulting is a much bigger issue, and where more disadvantages can likely be found. Comparing bipedal pole vaulting to pterosaurs is not even like comparing bipedalism to quadrupedalism in terms of running or walking (which would be bad enough), this is more like an Olympic pole vaulter using the pole as both a stilt to run on and a pole to jump on while shouting "look mommy, no legs!"

This post has been edited by Jarlaxle: Jan 17 2023, 03:52 PM

Bipedal pole vaulting is just a matter of keeping one's center of gravity over the feet, as any bipedal animal would do when crouching down before jumping/leaping, as that is what it is--a leap. It may not be able to accomplish quite as strong a leap depending on specifics, but it should still get the job done.

Though, I'm not even sure we should be calling it pole vaulting. I have never used that term in descriptions. I'd liken it more to a jerboa leaping, then flapping its legs instead of landing. The whole method of levering off the ground is more like that than what pterosaurs do.