it was made by chance in a dust cloud of mites that carried the black goo.. it was a crazy deleted sequence. The human would get liquified in a 0 gravity area and his floating genetic material would activate the dust mites to start creating and forming into the Belugahead.. an embryo looking alien.. so there's reason to all that you see in that design.. they tried to keep the folding up limbs with Fifield when he's sitting down outside the ship but it just didn't work with a man structure..
-Carlos Huante, from one of the reactions to the post Instagram post below.
