While some animals develop the mouth and anus by deepening the blastopore, a "dent" in the surface of the early embryo, the blastopore of brachiopods closes up, and their mouth and anus develop from new openings.
Sementara beberapa hewan mengembangkan mulut dan anus dengan memperdalam blastopor, sebuah "penyok" di permukaan embrio awal, blastopor dari brakiopoda menutup, dan mulut dan dubur mereka berkembang dari bukaan baru.