primitive streak formation
The developmental process pertaining to the initial formation of the primitive streak from unspecified parts. The primitive streak is a ridge of cells running along the midline of the embryo where the mesoderm ingresses. It defines the anterior-posterior axis.
GO:0048646
anatomical structure formation involved in morphogenesis
is_a
GO:0001702
gastrulation with mouth forming second
part_of
GO:0009948
anterior/posterior axis specification
part_of