primordium vs anlage

primordium and anlage both are nouns.

Word	Noun	Adjective	Verb	Adverb
primordium	Yes	No	No	No
anlage	Yes	No	No	No

As nouns, primordium and anlage are synonyms defined as:

primordium and anlage: an organ in its earliest stage of development; the foundation for subsequent development

primordium (noun)	anlage (noun)
an organ in its earliest stage of development; the foundation for subsequent development	an organ in its earliest stage of development; the foundation for subsequent development