Long ago in the very beginning of time there dwelt within a shell an infant god whose name was Ta'aroa. He was Ta'aroa the unique one, the ancestor of all gods, the creator of the universe whose natures were myriad, whose backbone was the ridgepole of the world, whose ribs were its supporters. The shell was called Rumia, Upset.

Becoming aware at last of his own existence and oppressed by a yearning loneliness Ta'aroa broke open his shell and, looking out, beheld the black limitless expanse of empty space. Hopefully, he shouted, but no voice answered him. He was alone in the vast cosmos. Within the broken Rumia he grew a new shell to shut out the primeval void.

Eons passed and Ta'aroa grew to be a lad conscious of his own vigor and potentialities. Impatience grew upon him until he could bear his isolation no longer. He broke forth from his shell with energy, resolved to create beings like himself who would banish his loneliness forever.

Ta'aroa's first act was to construct a firm foundation for the earth, using the strong second shell for stratum rock. The shell Rumia became his dwelling place, the overarching dome of the sky. It was a confined sky enclosing the world just forming, and in its deep and abiding night the lad attained manhood. There were no Sun, Moon, or stars and only one other living creature, the Great Octopus.

The sun was held down close above the slowly evolving earth by the Great Octopus, Tumu-rai-fenua, Foundation of Heaven and Earth, who lived in the primeval waters on which the earth floated. One of his arms was to the north, one to the south, one to the east and another to the west. With these vast arms he held the sky, the shell Rumia, close down against the earth.

Meanwhile on the earth itself various generations of rocks were born, one after the other; then sand appeared. Roots were born and as they spread they held the sand together and the land became firm.

Ta'aroa sat in his heaven above the earth and conjured forth gods with his words. When he shook off his red and yellow feathers they drifted down and became trees ... (Makemson, The Morning Star Rises)

In the rongorongo system the 'feather marks', which I use to call them, presumably indicate the flames from a fire. Flames move upwards, but the red and yellow feathers of Tagaroa drifted down from the sky and were transformed into trees, and from wood (of at least wood from some of the trees) fire can then be created. The cycle is closed.