Bryophytes (non-vascular plants) are more similar to ancestral green algae than are vascular plants can be included in the grade monilophyte because they do not have a complex vascular system are more similar to ancestral red algae than are vascular plants are evolutionarily more advanced than seed plants

I think in this case Bryophytes are more similar to ancestral green algae than are vascular plants. These plants lack a vascular system for transporting water and minerals, Unlike angiosperms they do not produce flowers, fruits, or seeds. They also lack true leaves, roots, and . stems, They appear as small, green mats of vegetation found i damp habitats. Lack of vascular tissues means that these plants must remain in moist environments. 

A- a reduction in biodiversity

They formed the oceans.  as they melted water was formed and the water made the oceans