The Word 'Protostome' Refers to "Anus First

Question

The word 'Protostome' refers to "anus first".

Accepted Answer

The word 'Protostome' actually refers to the embryonic development pattern of certain animals where the initial opening in the embryo becomes the mouth, and the anus forms later. This is the opposite of 'Deuterostomes', where the initial opening becomes the anus, and the mouth forms later.