What signs of bryophytes indicate the antiquity of this department among plants?

1) The gametophyte of bryophytes begins its life from the stage of protonema, which is a combination of one filament attached to the substrate and several photosynthetic ones. These threads are very similar to algal threads, they are single-row.
2) Gametophyte dominates. The sporophyte does not carry out photosynthesis on its own and is completely on the provision of the gametophyte.
3) Male sex cells are flagellated, and therefore the possibility of reproduction of bryophytes is entirely dependent on water.
4) Leaves often consist of 1 layer of cells, but there is no true vein.