nautili

A diver observes several nautili drifting near a coral reef.

Definition

1. Noun (plural form):
   • Marine mollusks: "nautili" is the plural of "nautilus," referring to a type of cephalopod mollusk with a spiral, chambered shell, found in warm ocean waters.
   • Historical or biological context: In zoology, "nautili" specifically denotes members of the genus Nautilus, which are living fossils that have remained largely unchanged for millions of years.

Usage Examples

• Noun:
  • The aquarium displayed several ancient nautili in its deep-sea exhibit. (Multiple nautilus mollusks were shown.)
  • Scientists study nautili to understand evolutionary biology. (Researchers examine these mollusks for scientific purposes.)

Advanced Usage

• "nautili shells": the spiral shells of nautili, often used in jewelry or decoration.

  • Collectors prize nautili shells for their perfect logarithmic spiral. (The shells are valued for their mathematical beauty.)

• "living nautili": a phrase used to emphasize that these creatures are still extant, unlike many related fossil species.

  • Living nautili are considered "living fossils" because they resemble their ancient ancestors. (They have survived with little change.)

Variants and Related Words

• Nautilus (n, singular): the individual mollusk.

  • A single nautilus can retreat into its shell for protection. (One mollusk uses its shell defensively.)

• Nautiloid (adj or n): relating to or being a member of a group of cephalopods that includes nautili and their extinct relatives.

  • Nautiloid fossils are common in Paleozoic rock layers. (Fossils of this group are abundant in ancient rocks.)

Synonyms

• Chambered nautilus: a common name emphasizing the shell's internal chambers.
• Pearl nautilus: a less common synonym for the shell itself.

Related Idioms

Phrasal Verbs