ammonoid
/ˈæməˌnɔɪd/
noun
- An extinct marine mollusk with a coiled, chambered shell, related to modern squid and octopuses.
- Ammonoids lived in the oceans for hundreds of millions of years before going extinct.
- Scientists study ammonoid shells to learn about ancient marine environments.
- The fossil collector found a perfectly preserved ammonoid in the limestone quarry.
Synonyms
adjective
- Relating to or resembling an ammonoid or its shell.
- The spiral ammonoid pattern appears in many natural forms, like certain seashells.
- The artist carved an ammonoid shape into the stone wall.
- The museum displayed a collection of ammonoid fossils from the Jurassic period.