Corpse not found/disappeared?

[Shejtana]

I was underground and died.
It was a place, where didnt were 2 blocks side by side.
The dead marker tells me that Im died at y 166 so right at overworld. But I was under this, at least 40Blocks. There was water nearby, not sure, if my corpse was going into water and flowed away?
Im not far in the game, so cant go down completely, there are to many mobs at bottom.
So what the mod does, if there are not 2 blocks side by side nearby?
Where should I look/search?
Worldspawn? Hill up? Down the waterpath? Nearby 20blocks?
Im not sure exactly how much down I was.