Definition

1. Adjective:

   • Relating to the class Crinoidea: Describes anything pertaining to the class of marine animals known as Crinoidea, which includes sea lilies and feather stars.

2. Noun:

   • A primitive echinoderm: A marine invertebrate animal belonging to the class Crinoidea, characterized by having a cup-shaped body (calyx) with five or more feathery, flexible arms used for feeding.

Usage Examples

• Adjective:

  • The fossil displayed distinct crinoid features. (The fossil showed characteristics typical of sea lilies.)
  • They studied the crinoid anatomy. (They studied the physical structure of these echinoderms.)

• Noun:

  • A crinoid was attached to the coral reef. (A sea lily was fixed to the coral reef.)
  • The diver observed several crinoids filtering food from the water. (The diver watched several feather stars capturing food particles.)

Advanced Usage

• In Paleontology: The term is frequently used to describe fossils of these animals, which are common in sedimentary rocks.
  • The limestone layer is rich in crinoid stems. (The limestone contains many fossilized columnals from the stalks of ancient sea lilies.)

Variants and Related Words

• Crinoidea (n): The scientific class name for crinoids.
• Sea lily (n): A type of crinoid that is permanently attached to the seabed by a stalk.
• Feather star (n): A type of crinoid that is free-moving or can swim, often lacking a long stalk in its adult stage.

Synonyms

• Sea lily (for stalked varieties)
• Feather star (for free-moving varieties)

Related Terms and Phrases

• Crinoidal limestone: A type of sedimentary rock composed largely of crinoid fragments.
  • The building was constructed from crinoidal limestone.
• Crinoid stem: The stalk-like structure of a sea lily, made of disc-shaped ossicles.
  • The fossil site contained numerous crinoid stems.

Adjective

1. of or relating to or belonging to the class Crinoidea

Noun

1. primitive echinoderms having five or more feathery arms radiating from a central disk