f-nodragonart:

I would advise researching how the shape of an animal’s facial structure changes as it matures. A lot of animals are born with shorter, more rounded skulls that lengthen/expand as they mature, and of course you want them to have proportions of large heads and small limbs. Bats are born with well developed, albeit small wings, they don’t need to grow them. Growth of wings if they are bat or pterosaur-like should be proportional, with the finger bones becoming longer.

Growing wings without some kind of metamorphosis in water or a chrysalis is indeed ridiculous. Bones have to develop in buoyancy until they more or less achieve their final shape and ossify, after which they grow in a somewhat linear fashion. Entire bone structures can’t grow after birth without an aquatic lifestyle, because without buoyancy, the bones would be deformed by gravity. Antlers aren’t subject to this problem because they don’t have layers of flesh putting weight on them.

That said I still don’t think an amphibious lifestyle is likely in a highly advanced creature, because it’s fundamentally r-selected. The more complex an organism is, in regards to how long it takes to mature and conversely, would NEED to take to mature because complex features just can’t develop super fast, the more K-selected a life cycle it needs. K selection is important to maximize survival rate in organisms that require a long time to reach maturity.

Long story short, if you want an amphibious lifestyle and K-selection, I have an idea for that which I use in one of my fictional creatures. Your animal could build waterproof nests and dump/cycle water in those, in which it could birth larval offspring which could undergo their amphibian-like metamorphosis in a relatively safe environment, yielding a high survival rate.

But I got off topic and rambled there a bit, haha. Some more tips I have for indicating juveniles as being distinct from adults, besides the general proportion differences, is messing with coloration, even if they don’t have feathers. Fawns have distinct fur markings different from adult deer. Pacific beetle mimic cockroaches are born with orange heads which makes the youngsters clearly distinguishable from mature animals.

-Mod Exodrake