Animals having two embryonic layers are known as diploblastic organisms.
The two embryonic layers are ectoderm and endoderm.
Ectoderm is the outermost of the three primary germ layers which are responsible for the development of an embryo that is the source of various tissues and structures.
Whereas endoderm is the innermost germ layer that forms the linings of the respiratory and gastrointestinal tracts, and their associated organs, during embryonic development.