Already answered in the Discord but:
They would probably recognize young metamorphosed kurtbacks as competitors instead of prey by virtue of the special tail and size (small, but still bigger than any teacup sauce).

Would it take very long to adapt to use it in water? I wouldn't expect much necessary difference other than the frequency used. https://www.encyclopedia.com/plants-and-ani...tion-physiology That said, this site says echolocation of a given resolution in air would need to be five times higher frequency in water, so maybe that's too significant of a difference to alter in one generation anyway.

I do think that the bat underwater thing is a false analogy, though, as bats are not adapted to hunt in water and probably don't want to be put there.

The description here says that echolocation is "mostly ineffective" in the water. Is this just because of the biome this organism lives in? Because, while mangal and riparian biomes do inhibit sonar somewhat, it's still a very useful sense to have in the water (especially for an organism that cannot see).

and now i'm reminded of how i probably won't be able to submit mauvacken for an indeterminate amount of time

anyway the colors on these remind me of the three cobble-family stone types in Minecraft. I don't have any other real input since I know diddly-squat about this lineage.

Name: Kurtback (Vermisorex vonnegutii)
Creator: Cube67
Ancestor: Teacup Saucebacks
Habitat: Vonnegut Subpolar Volcanic, Vonnegut Subpolar Beach
Size: 35 cm long
Support: Endoskeleton (chitin)
Diet: Adults: Carnivore (Teacup Saucebacks, Silkruggs, Minikruggs, Scuttlers (uncommon)); Larvae: Omnivore (Teacup Sauceback larvae, Vermees, Sunstalk roots, Supershroom roots, Cryobowl roots, Pioneeroot roots, Marbleflora roots), Scavenger
Respiration: Active (microlungs)
Thermoregulation: Adults: Endotherm (feathers); Larvae: Ectotherm
Reproduction: Sexual (male and female, oviparous, subterranean larval stage)

The emerging ecosystem of the Vonnegut islands is a unique one indeed. As these islands emerged so far from any other land, only the smallest and most abundant terrestrial organisms managed to colonize the archipelago. Though most of the region’s native fauna are unable to attain a large size, one group stands out amongst the crowd: the teacup saucebacks. Being descended from much larger creatures, it was only a matter of time until one of these species began getting big again.

Hunting
With little competition to hinder its growth, the kurtback is over three times longer than its closest relatives on average. Due to this size advantage, mature kurtbacks are able (and, in fact, specialized) to feed on other shrewbacks. Kurtbacks hunt in a manner not dissimilar to an earthling cat. Their feet are covered in soft down, keeping them warm in the dead of winter while also allowing them to stalk their prey without making a sound. This, of course, is hugely important to a species whose main prey item relies chiefly on sound to perceive the world around it. Additionally, kurtbacks do not emit sonar calls while hunting, using their prey’s calls to echolocate instead.
Once a kurtback is close enough to its prey, it gives chase, holding its robust jaws wide open. While a teacup sauceback has a top speed faster than that of a kurtback, its small size and high metabolism mean that it loses momentum quickly enough for the kurtback to pounce on it after only a few seconds of chasing. A kurtback pounces head-first, locking its jaws on the first part of a prey item they touch, killing it instantly.

Life Cycle
Similarly to their ancestors, kurtbacks begin their lives as tiny eggs, though now they are buried in a shallow depression in the soil instead of laid in the open. While kurtback larvae are very similar in appearance to those of their ancestors’, they are distinguished by several important features, just like the adult. Kurtbacks are more K-selected than most shrewbacks, laying slightly fewer eggs but having the larvae hatch at nearly 5 millimeters long to compensate. This adaptation originally gave these larvae a developmental advantage over other shrewbacks, but as in the adult kurtback, this size difference also helps kurtback larvae catch and eat (the larvae of) teacup saucebacks. To avoid competition with adult kurtbacks and other shrewbacks, larval kurtbacks often supplement their carnivory with a variety of roots and tubers, making them mesocarnivores. It’s worth noting that while adult kurtbacks have a slightly lower metabolism than their relatives due to their larger size, larval kurtbacks have a slightly higher metabolism than other shrewback larvae, enabling them to dig through the ground a little faster than their prey.
As the soil of a subpolar volcanic island can be a harsh place for an ectotherm, kurtbacks metamorphose earlier in their life cycle than other teacup saucebacks. While teacup sauceback larvae usually reach the length of the adult form before metamorphosing, kurtback larvae only reach half of their maximum length (17 cm), with the remainder of the growth happening in the adult form. Kurtback larvae still grow hair and store a large amount of fat before metamorphosis.

Integument
Since kurtbacks spend longer out in the open than their relatives, they have developed a variety of integumentary adaptations to deal with the cold environment. Kurtbacks have a distinct summer and winter coat of feathers, with moulting between the two triggered by the year’s first thawing and first snowfall, respectively. A kurtback’s summer coat is composed of thinner, black feathers, which help it blend in with the volcanic rock and soil it calls home. The winter coat, meanwhile, is composed of a dense layer of white feathers, keeping the kurtback warm and helping it blend in with the snow. A kurtback’s feathers are replaced as they fall out, giving the kurtback a mottled grey (or “blue”) look during the brief moulting period.
The sclerites of a kurtback undergo a similar color change to the rest of the body, but by a different mechanism. When changing to the winter coat, the black pigment in the jaws, teeth, sauce, claws, and tail spike is dissolved, with the pigment being regenerated during the transition to the summer coat. While the changes in feather and sclerite color don’t hide the kurtback from the blind teacup saucebacks, it does hide it from their other prey items like kruggs.

Courtship and Behavior
Perhaps the most unusual thing about the adult kurtback is its tail spike, which now appears more like a strange fin than it does a tiny spike. This structure is for sexual display, helping kurtbacks identify each other quickly and making them more attractive to mates. Although kurtbacks are completely blind, they are able to “see” this tail spike especially well via sonar. It is much larger, flatter, and denser than in other saucebacks, perfect for reflecting sound. Larger tail spikes are also favored by both sexes as a display of fitness: the logic goes that individuals able to maintain a larger tail spike must be better at hunting and surviving. This is because the structure essentially serves as a handicap. It radiates a lot of heat due to its flat shape, making it harder to thermoregulate. It is also somewhat cumbersome and makes the kurtback more “visible” to its prey, making it trickier to hunt.
Outside of courtship, kurtbacks are largely solitary, viewing other kurtbacks of the same sex or of much smaller size as competition. Rival kurtbacks generally don’t fight each other, but they do use the size of their tail spike to try and assert dominance. While this may seem like a purely selfish trait, it actually benefits newly-metamorphosed kurtbacks, which could otherwise be seen as food by fully grown individuals. Kurtbacks are not particularly smart for a sauceback, typically ignoring or avoiding new stimuli that they don’t recognize as food, foe, or partner.

Supplementaries (these go with the integument section)

Winter coat

Moulting

Why such a sudden appearance of iron respiration? Do the roots house symbiotic microbes that carry out the respiration or something?

I'll just mention the fact that "biomass" as a diet is really unspecific and isn't one of the diets that the rules officially support (imagine if every carnivore/herbivore/omnivore/scavenger/detritivore/planktivore simply listed "biomass", that would be unhelpful to say the least).

Hey, hold on a minute, why are the tail spikes now oriented vertically instead of horizontally?

'twas brought up and resolved in discord but i thought i'd post it here:
a weird dead amphibian called Mastodonsaurus does this same thing, apparently. I'd actually bet that Ovi based this creature off of it, at least for the tooth part. Nature is weird.

If you're thinking of the babirusa, that's the top teeth coming out of the top jaw, not the bottom teeth. I'd say it's a different situation from here due to the fact that the babirusa's tooth is only piercing through flesh (not bone) and is rooted to the same structure that it pierces through.

I'm frankly suspicious of the whole tooth concept. Why couldn't the jaw have simply deepened to account for the teeth? Why not grooves for the teeth to slide into like a saber-toothed cat? Both of those solutions are present in nature, but there aren't any real organisms with bottom teeth that poke through the top jaw, which leads me to believe that it's a less likely outcome to evolve.

you're right that is a cursed genus name

@Coolsteph The error has been fixed.

Orange trees magically take root in your house and grow rapidly. This causes untold structural and water damage, ruining your home and posessions. You do get to have the oranges, though.


I wish for some nice art paper.

Mammal flea. wow.

I wonder what just a few more generations could do to this? maybe a smaller number of longer teeth would be better for puncturing skin eventually.

Oh.


Oh dear.


How sus this species is.

'twas I, sorry. I complained about the old one (Flightless Soaring Pinyuk) being generic and hard to remember, which I still think would've been a problem if this formed into a major clade or anything. But distress was not my intent, if there was any.

There, fixed. Although... tell me if it might need a new genus. I don't think so but maybe someone else will.

Anyone else have something to say about this? (it's been a couple of days so i'm commenting to bump this post back to the top)

Also, I noticed that the support section isn't formatted correctly.

This.... this creature has to be the weirdest (plausible) one i've seen from this timeline.

Regarding the shell color change: I suppose it's better than nothing. Maybe it makes sense if you consider a partially buried recently detached stembud, for example, which wouldn't be as tall and obvious. I should probably check if there's any other green flora here (other than the original gumjorn).

Name: Driftwood Gumjorn (Peposoci fluitolignum)
Creator: Cube67
Ancestor: Gumjorn
Habitat: Driftwood Islands Tropical Bank, Driftwood Islands Temperate Bank, Driftwood Islands Tropical Woodland, Driftwood Islands Temperate Woodland, Driftwood Islands Chaparral
Size: 70 cm tall
Support: Chitinous shell, hydrostatic pressure
Diet: Photosynthesis
Respiration: Passive (stomata)
Thermoregulation: Ectotherm
Reproduction: Asexual (budding)

The driftwood gumjorn split from its ancestor and adapted to life on the strange and ever-changing driftwood islands. This unique flora possesses a variety of adaptations to suit its new environment.

In order to obtain more energy from the sunlight which it requires to live, the driftwood gumjorn’s ‘windows’ have expanded similarly to those of its relative, the ornate gumjorn. This makes it easier for the driftwood gumjorn to photosynthesize but sacrifices some of the strength its chitinous shell would otherwise provide. Not only do these larger windows help to fuel growth, they also make the driftwood gumjorn more shade-tolerant, expanding its range into the wooded areas of the islands. In order to conceal itself from predators a little better, the driftwood gumjorn’s chitinous frame has become a more dark and muted shade of brown, mimicking the color of mud and rotting plant matter.

To compensate for the somewhat extreme environment in which it lives, the driftwood gumjorn has evolved to produce more offspring at a time. These ‘stembuds’, as they are called, are each homologous to the gumjorn’s basal segment, but have a different aspect ratio and lack the deep grooves found on the mature flora. Strangely, every driftwood gumjorn can actually produce two types of offspring, the differences between the two types being regulated by just a couple of genes that control important aspects of the gumjorn’s growth and development. The usual type of offspring, as depicted in the main image, is somewhat elongate and egg-shaped, with only a small amount of salt being transferred to them during their development. However, if the driftwood gumjorn accumulates too much salt, it will grow a degenerate, spherical stembud about one third of the length of the regular type and with no windows. This type of growth, called a saltbud, has a large amount of saline diverted to it during its development. At the end of the saltbud’s development, most of the water is pumped back out using transport proteins, and the salty husk detaches and is left to die. This is a highly effective osmoregulatory system, as the driftwood gumjorn can grow both types of stembud at the same time, the proportion of the two types depending on how much salt is currently present in the gumjorn’s system.

Driftwood gumjorns, while not having as extensive a root system as some other flora, do have long and fibrous roots that radiate outwards horizontally. These thin and tangled roots help to hold the driftwood soil together.

Also, one question: by what mechanism does The Hideous "cackle"? What does it sound like?

@Coolsteph The Hideous does happen to look pretty similar to my own idea for the kugard lineage, particularly regarding a hint of bipedalism and extended heels... hopefully they won't compete too bad.

Pictured: a rough sketch of a primitive 'megakugard' I envisioned a while ago