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Glite Dictionary
🧬 Animal with mouth first 🧬 Mouth forms first
protostome

protostome

1 9.9
Relating to animals whose mouth forms before the anus during early development
  • adjective
  • /ˈproʊtəˌstoʊm/
  • Specialized
: protostomado
  • The protostome animals include mollusks and annelids.

Examples

  • In biology class, we learned about protostome development in worms and insects.

  • The scientist explained the differences between protostome and deuterostome animals.

  • Mollusks are a common example of protostome organisms in the animal kingdom.

  • Are all protostome species aquatic?

  • In biology class, we learned about protostome development in worms and insects.

  • Mollusks are a common example of protostome organisms in the animal kingdom.

  • The scientist explained the differences between protostome and deuterostome animals.

Surface Forms

protostome positive

Morphology

protostome = proto + stome

The term is built from the classical element proto- meaning 'first' and the bound form stome meaning 'mouth/opening', but the second element is not a common standalone English word, so the meaning is not straightforward for typical learners.

Etymology

Protostome comes from Greek parts proto- meaning 'first' and -stome meaning 'mouth', just like the proto- in prototype, so it describes animals where the mouth forms first in early development.