Quick sketch of how I conceptualize this creature's skeleton. Sorry for the chopped off head, the jaw design and such isn't finished. The 4 yellow bones on the tip of the neck are the base of the jaws, but it's obviously unfinished.
There are other problems with this alien's skeleton too, such as the shoulder blades, highly encased "ribcage", and inflexible ventral spine/bone... but today I'd only like to focus on what's really upsetting me about the skeletal structure of this guy:
I'm not sure how I can have a strong, flexible support for the neck and still have space for an esophagus that lines the underside of the neck. I don't want food coming in through the top of his head (such as that when he swallows, it'll look like the top of his neck is taking in the food) even though that's the most logical way to go for a ventral spine.
I also don't know how food will empty into his stomach if the esophagus is on the underside and the spine is attached to the bottom of his body. One way I could combat this is making it so that he digests food through an intricate system in his neck, like a modified, winding, slow moving intestine. There isn't much going on in this alien's neck anyhow. His neck is essentially an extension of his mouth; it doesn't house a brain or eyes, and he breathes and 'smells' cutaneously through his mouth lining. The only issues that may stem from doing this is the act of expelling waste. Unless the waste is in liquid form only (unlikely), then it'll have to move away from the neck somehow, and the problem I currently have in placing the esophagus will be repeated.
So... any suggestions? The only things I don't really want to trade off design wise are:
- The ventral 'spine'
- The long flexible neck and mouthpart that consumes food
- A bilaterally symmetrical organ placement (I don't want the esophagus 'bending left or right into' the gut)
And the problem I'm avoiding is:
- A dorsal esophagus
EDIT: Another problem is that this creature eats in chunks or swallows it's food whole. Yes, I know the ribcage will pose a problem with this already; this is just a sketch. The ribcage isn't all bone anyway, just the trailing edges and base of it; the center of the ribcage is a sort of stretchy ligament that calcifies at the ends, allowing it to extend horizontally.
Anyway, being that it swallows it's food whole or in large chunks, I can't have a split esophagus run up into the gut because it would need to be much narrower at the splits. The only workaround to that I see, is making the esophagus a modified intestine (sans stomach entirely) and make the waste (provided that the waste is quite small or soft initally) go through two tubes running up into the gut and expelled out through an aperture on the bottom of the creature (maybe the bottom end of it, that way the tubes act as a sort of 'small intestine' that further extracts nutrients from the waste).
EDIT 2: My drawing may have been unclear because of all the clashing colors, overlapping lines, and how there appears to be a dorsal spine already, so I made a less-busy drawing that I hope clears up the confusion: