exocycloida

Thân thiện

A marine biologist carefully observes an exocycloida on the ocean floor.

Definition

1. Noun:
   • A taxonomic order of echinoderms: "Exocycloida" is the scientific name for an order of sea urchins characterized by a flattened, disc-like shape. These are commonly known as sand dollars or heart urchins.

Usage Notes

• "Exocycloida" is a highly specialized, technical term used almost exclusively in scientific contexts, particularly in zoology, marine biology, and taxonomy. It is not used in everyday conversation.
• As a taxonomic order name, it is always capitalized.

Examples

• Noun:
  • The fossil record shows that Exocycloida have existed for millions of years.
  • Marine biologists classified the newly discovered species within the order Exocycloida.

Advanced Usage

• In formal scientific writing, the term may be used in its taxonomic hierarchy.
  • The class Echinoidea includes the orders Camarodonta and Exocycloida.

Variants and Related Words

• Exocycloid (adj): Pertaining to or characteristic of the order Exocycloida.
  • The exocycloid test (shell) is highly adapted for life on the seafloor.
• Clypeasteroida (n): A synonymous order name often used in modern taxonomy for the same group of flat sea urchins.
• Sand dollar (n): The common name for many living species within Exocycloida.
• Heart urchin (n): Another common name for species in this order, referring to their shape.

Synonyms

• Clypeasteroida: The more modern, alternative scientific name for the same taxonomic order.
• Flat sea urchins: A descriptive, non-technical term.

Related Phrases

• Irregular echinoids: A broader category of sea urchins, including Exocycloida, that have bilateral symmetry adapted for burrowing or living on sediment.

Học thuật

Noun

1. flat sea urchins

Từ đồng nghĩa

• Exocycloida
• order Exocycloida