lancelet

/ˈlænslɪt/
noun
  1. A small, fish-like sea animal that lives in sand and has a simple body without a backbone, considered a primitive relative of vertebrates.
    • A lancelet looks like a tiny, transparent fish but has no true skull or backbone.
    • The lancelet is often studied by scientists to understand the evolution of backbones.
    • Lancelets bury themselves in the sand and filter food from the water.
Synonyms