not sure whether anyone brought this up yet, but I am pretty sure the turaga have been confirmed as "building matoran using a machine that just pops them out"
now, scientifically, matter (in this case a matoran) cant come from nothing. so what where matoran befor they where...Matoran,
I am not going to the "dead bodies" level (after death matoran where transported whole to the redstar, effectivly being teleported there, meaning no corpse)
but what was it?
best case, plants, as that makes sense with the organic of everything to a point. but plants may not be molecularly the same as matoran. as in, different atomic structure and types of atoms.
worst (and for the sake of this argument, more likely) Rahi. I am going to say rahi.
the turaga killed innocent animals to make more matoran.
second horrifying revelation:
when you realise mask of light was actually not all that good, legends of metru nui was better, web of shadows was the worst, legend reborn wasn't too bad and everything you believed as a child was wrong.
or is that just me?