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The uterus does not participate in the mechanical stresses of movement. It is not invited to that party and it does not want to go. A uterus has uterus things to worry about. It no more participates in skeletal movements than any other smooth muscle structure. Stresses of movement are distributed about the skeleton and core muscles. As regards the ...


30

I think you are starting from a false premise Blue is a rare color in nature. It would be more correct to say that our eyes are made in such a way that we don't see that much blue around, because they are not so sensitive in the UV part of the solar spectrum. Just give a look at how different birds see the world around us (of course the rendition of the ...


14

Short answer: no. Long answer: almost certainly not. The four limbs and (optional) tail body plan is baked into vertebrates. ALL vertebrates. Not just mammals, but reptiles, amphibians, fish -- anything with a spine and bones (or even cartilage) has been four limbs and a tail (with the option to minimize or even eventually delete any of these due to ...


14

From my small knowledge of biology, animal colour is either to hide the creature or to highlight it. So if there is a significant variety of predators then almost everything would want to camouflage, prey to stay hidden, predators to sneak up on the prey. so if on you planet, instead of the browns of bark and the greens of leaves, you have instead both the ...


13

Soft Shells Without being much of an engineer it seems like the best way to handle this from the bird's perspective would be to lay a soft-shelled egg that hardens upon exposure to the air. The softer shell would be able to flex in the uterus until it was time to lay it, so the flight action wouldn't be able to crack it. Depending on the mechanical ...


11

Copper Sulfate Your planet's creatures need lot's of copper(II) sulfate as an essential nutrient for some metabolic process. Copper(II) sulfate has a bright blue color when dissolved in water, so as long as your planet has a lot of it as life evolves, it may be incorporated into some metabolic process. Admittedly this is unlikely, due to copper's density and ...


10

The dragons are aerial siphonophores. https://c1.staticflickr.com/1/400/19724048832_e1a82de8be_b.jpg https://en.wikipedia.org/wiki/Siphonophorae Although a siphonophore may appear to be an individual organism, each specimen is in fact a colonial organism composed of medusoid and polypoid zooids that are morphologically and functionally specialized. Zooids ...


9

I'm not convinced it would be a problem. Eggs crack easily to impacts, but have incredible compressive strength. So it's trivially easy to break one with a knife or fork or edge of pan, but just try squeezing one to death. You may not be able to do it, and if you do it will take a lot more effort than you'd think at first. This was a bit of a meme in the 20-...


8

Some Already Do In the Chernobyl exclusion zone, flora and fauna are doing better, in many ways, than they did pre-irradiation, by means of the radiation driving off their major competitor - namely, us. They have to suffer the effects of the radiation, but it's a lot less trouble than human civilization/human predation. More Realistically Radiation is a ...


8

Photosymbiotic great barnacle. For reference: regular barnacles. https://seahistory.org/sea-history-for-kids/barnacles/ The barnacles are the only sessile members of crustacea, and the giant barnacle leverages the robust crustacean body plan to outcompete other sessile marine organisms with photosymbionts. As with other photosymbiotic marine organisms (...


7

Yes, totally The mammal body plan accounts for five limbs: either 2 arms + 2 legs + tail, or 4 legs + tail. Some mammals have evolved to have no tail at all, some oceanic ones have evolved to have no legs. But just like they evolved to lose limbs, they might evolve to gain limbs. Kangaroos sometimes walk on four, and they are able to stand on their tail; if ...


7

It Hunts Foliage Your demigryphon looks just like a ceratopsian. While the gryphon's beak is definitely different, it's far closer to ceratopsian than any large predator I know. Hence the demigryphon is likely a similar creature, and at least is similar in diet The specifics of the demigryphon have good explanations under this idea. The strong cursorial legs ...


7

They don't choke them, they sever their spine, and will hunt much like a large tiger. The first thing we have to take care of is the beak: most felines today don't exclusively use their claws to end prey, and thus the head will need to be of use in the taking down part. You're right that a beak is normally not what you think of when you think of a pair of ...


7

Your question asks "what adaptions are needed", rather than the more obvious "Earth is filled with small animals who aren't dead, Why is that?" L.Dutch has answered part of this, which is that small things have less to worry about when it comes to falling, but there's a second factor... reaction times, which you're calling $r$. The time ...


7

Your crocodilian will have to be pretty different for that to work. Crocodiles are "simple" creatures. They stay in water, they drag prey into the water, they death roll it and drown it. Many Crocodilians also don't mind eating carrion, and thus can store prey underwater to soften up the meat. Your crocodilians are completely unlike that. Despite ...


6

Classic Conditioning This parasite can 'train' it's subjects similarly to how humans train pets: classic conditioning. Just give it a way to inflict a punishment, like pain, in a quick timespan. Then it simply punishes whenever the subject does something it doesn't want, and the subject will eventually modify behavior to avoid the punishments. There is not ...


6

Yes, for a given value of radiation When you say radiation, you probably mean ionizing radiation. As jdunlop explained, using this is suicide. But guess what, visible light is also electromagnetic radiation! Some jellyfish that live in the abyssal zone are bioluminescent, but they only light up when they are attacked. One idea is that if they are predated, ...


6

I was wondering which type would be more efficient at it Efficiency in swimming comes from adaptations to swimming. If you're not adapted to the sea, you're not going to be great moving about in it. Get you some swimming fins, or a nice tail. Humans can swim OK, but imagine if we had skinny plantigrade legs with claws on the end, in a vaguely birdlike ...


6

I feel an unaccustomed humility, thinking of how to improve the jellyfish. The jellyfish! Oldest of us, how can my little schemings improve on 500 million years of your trials, your survival of the fittest? Let us consider the squid. https://www.researchgate.net/figure/Conceptual-diagram-of-underwater-jet-locomotion-for-both-a-squid-and-b-...


6

You are worrying for nothing. I have seen 4 nieces learning to walk, with all the related falls. Infants don't have the fast reaction time of an adult, nor the adult's motor coordination, yet they manage to survive falls during their learning phase, as it is proved by the fact we are not extinct. How is it possible? With smaller bodies comes also a lower ...


6

Circular digestive tracts pose problems. You have food pass through the stomach (stomachs?) into the intestine. Then back from the intestine into the stomach(s). /Each time the nutritional value decreases, it returns to the stomach, where it is fermented further for a long time./ So from the stomach to the intestine and back. The small intestine also, if ...


6

Look to sponges and corals: Physically, something that doesn't move has a very different set of evolutionary pressures on it. You chief factors will be food supply, predation, and parasitism. Mega-barnacles will need a lot more food passing through their filters. Their hunting style may come to look more like a spider or fishing trawler sending out nets to ...


6

Possessed by devils Book of Mark, 5 5 And they came over unto the other side of the sea, into the country of the Gadarenes. 2 And when he was come out of the ship, immediately there met him out of the tombs a man with an unclean spirit, 3 Who had his dwelling among the tombs; and no man could bind him, no, not with chains: 4 Because that he had been often ...


5

Those creatures already exist. You should be able to find them on a rocky coast. On a place where the waves hit frequently or on a place that gets wet when the tides rise. I present you the Patella Vulgata, or limpet. Although you are not used to see that side. You will recognise them better in this other image: In truth, any type of snail with one shell ...


5

Blood Loss Wolves beat prey to death with their teeth. I'm going to say that again, because it's just so metal. Wolves beat prey to death with their teeth. When a wolf bites (often a large muscle like the quad) it applies tremendous force into the relatively small surface area of its teeth. The wolf generally does not kill in one bite, but rather strikes ...


5

They jump off a height and use the free fall to get the needed speed to fly. For landing they need to slow down until they basically stall and do a controlled crash, and prefer doing it on elevated places, from where they can take off again. This implies that they need to fully feed while airborne, thus they feed on flying insects and other small things ...


5

The closest real mammalian counterpart from a creature like yours in terms of overall bodyplan (arm flippers, feet acting like fins) are seals and sea lions, and sea lions don't quite fit the bill since their 2 legs are still very much capable of acting like decently standard legs, unlike the legs of a seal which are essentially locked in a perpetual ...


5

Would the suggestion of the female going into a period where she does not fly during breeding season prior to the egg being laid violate the "Not fly at all" rule? This would see her enter a dormant or hibernation like period proceeded by a period of aggressive eating to build up fat stores for the time she would be unable to find food. ...


5

External gill hair. image source The external gills have the entire length of the body to hang down, and minimally encumber the humanoid. Augmenting blood flow to the head is no huge ask - the head has 4 big arteries supplying it already and gravity can help with the venous return of oxygenated blood. Plus all that red gillage is a rocking look. But be ...


5

You make such a liquid yourself! https://anrcatalog.ucanr.edu/pdf/8255.pdf Yes you do you wondrous creature! I do too. Also the dog, that used its growth-potentiating liquid on the depicted grass. Marvel at its lush greenness! The grass next door is jealous and hopes the dog will come back with more. A biological liquid containing nitrogen, phosophorus ...


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