crinoid
Học thuậtThân thiện
Definition
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.
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
- of or relating to or belonging to the class Crinoidea
Noun
- primitive echinoderms having five or more feathery arms radiating from a central disk