Here is a list of observations I made about the skeleton (pretty interesting, really, if you're into biology or archeology or anything sciency, really).
1. since in all cases, the biology of 4546B is very similar to that of Earth, (since they're both largely oceanic rocky planets, this makes sense,) we can notice that the lost river creature likely had four eyes and a neck joint very different from that of any creature of earth, (since the three indentations we see in the side of its head head are three rather than four like in a T-Rex, and none of them look like the fourth gap where the T-Rex's neck meets its skull. Therefore, the lost river skeleton likely had four eyes and no sense of smell or six eyes and.. very... few senses; (although this would make sense if the creature were more like an eel). This is supported by the biters quadruple eyes. (note that I used the T-Rex as an analogue because the creature in the lost river appears serpentine and eel-like and the Saurians of earth had many similar bone structures as reptiles like snakes.)
2. It might have been so ancient a creature that rays were also derived from it, since it has a pair of horns which reminisce of the rabbit ray.
3. An eel is not a very good analogue for this creature because eels have a skeleton, (specifically rib-cage,) more like the transparent river eels; and so must have been more similar to an aquatic reptile and so a Tyrannosaurus is a very good example for it to follow.
4. We now know that the creature was very different from the other creatures on this list and would have been something similar to an aquatic reptile in bone structure rather than a 'fish' like an eel. We can also make the leap that creatures like Stalkers evolved from it; since stalkers do look a good deal like some prehistoric fishes of earth like the late species the Mixosaurus.
5. This creature, due to its amazing size and obvious need for circulation due to its monstrosity, wouldn't be able to survive at very deep depths. The reason, of course, is that any creature that has to capture gas in their lungs to breathe will encounter the pressure inside their lungs gradually becoming greater than the pressure outside their lungs the deeper they went; meaning that the creature might suffer spontaneous lung collapse as I imagine. Another danger, if they have some special way of depressurizing a layer of specially-fit blubber for example, they would also experience all of the oxygen still in their bloodstream gathering into bubbles and giving them fizzy seltzer blood. But really though, the brain would not be able to absorb these bubbles of air and the owner of the brain would suffocate. And so, it would probably have swim bladders so that it could float along at around where the current reefbacks of Subnautica would cruise.
6. A living specimen would be something like 1200 meters long
7. In order to survive, it'd need some crazy source of calories; and so it likely lived in a world of leviathans
8. Had something like fins on the bottom of its jaw along its cheek jutting out at an angle; maybe bioluminescent.
9. Would have gone after much smaller prey since although its bite is huge, it takes up like a 15% of its entire body length.
10. Would have been so freaking stupid. It's brain to body mass ratio would be worse than any of the sentient creatures on earth. Think earthworm with fangs and a predatory mouth.
Here are a list of observations which make this all sound ridiculous:
1. it's spinal cord is along its stomach and chest, and not the other way around like it is for most creatures with a rib-cage (this means that it would have a behavior like a sandshark and await prey before popping out of the sand, and grabbing its prey. However, due to one of my other points, it'd have to stay in the shallows in order to be able to do this)
2. Eel skulls have only one indentation in the side of its head and don't have a ribcage. T-Rex's, for instance, have four indentations in their skull and have a ribcage. The lost river creature has three indentations in its skull, a ribcage, but its spinal cord somewhere on its stomach and probably can't move its neck very well because it doesn't appear to be attached to its spinal cord.
3. I'm beginning to wonder if the precursors messed around with the skeleton a bit more than I thought previously. Maybe they engineered the corpse as a practical joke for explorers to come, who knows.
4. Along with my precursors theory, this might be one of those 'put the head of the diplodocus on its tail again' moments. (scifiwriterguy is going to give me so much crap if I got that reference wrong)
![:#]( ":#")
5. Might have lived at a much cooler climate. Lizards, (which are resilient against heat,) tend to have flatter skeletons. This creature, however, what with being so large, would need a way to get rid of its excess heat well; and since I don't see any scales on it it'd be better fit for a cooler climate which might have actually helped with the whole pressure thing. (note that the river creature, although gargantuan, is long rather than fat. A superheated sphere will trap more heat than a superheated cylinder of the same mass yet greater surface area; part of the reason, (I imagine,) that snakes like to curl up into mounds when its cold and dark out.
P.S. I really do fear that
@scifiwriterguy has already read this entire document and is preparing to post a page worth's of comments describing his own opinion on the matter.
