Cells that can divide in a third plane potentially allow for the organism to develop a more complex body plan .
Diversification of body plans into an erect thallus of some sort and a holdfast for attaching the upright portion to the substrate .
Cells that can divide in a third plane potentially allow for the organism to develop a more complex body plan , and diversification of body plans into an erect thallus of some sort and a holdfast for attaching the upright portion to the substrate .