A layer of cells produced during the process of gastrulation during the early development of the animal embryo, which is distinct from other such layers of cells, as an early step of cell differentiation. The types of germ layers are the endoderm, ectoderm, and mesoderm.
hog:0000152
embryonic mesodermhog:0000153
embryonic ectodermhog:0000154
embryonic endodermhog:0001222
primitive endodermBFO:0000050
part of
hog:0000671
tao:0001122