noun
- An animal whose mouth develops from a second opening in the embryo, with the anus forming first; includes echinoderms, chordates, and humans.
Usage: biology; technical
Examples
- Humans are deuterostomes, meaning our digestive tract develops with the anus forming before the mouth.
- Echinoderms and chordates are classified as deuterostomes based on their embryological development.
- The deuterostome lineage includes starfish, sea urchins, and all vertebrates.
- In deuterostomes, the blastopore becomes the anus during early embryonic development.
- Biologists distinguish between deuterostomes and protostomes by studying how their mouths and anuses form.