protostomes
/ˈproʊtəˌstoʊmz/
noun
- The plural form of protostome; a major group of animals that share the characteristic of the mouth forming from the first embryonic opening.
- Scientists compare protostomes and deuterostomes to understand animal development.
- Protostomes include a vast diversity of species, from earthworms to lobsters.
- The evolutionary success of protostomes is evident in their many habitats.