Crossword clue: thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)

The most common answer is amnion (6 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

amnion 6 letters wn-def

thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)

amnios 6 letters wn-def

thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)