Definition

Noun: - Family Limulidae: A biological family within the class Merostomata, comprising the horseshoe crabs. These are marine arthropods known for their hard, horseshoe-shaped carapace and long, pointed tail spine (telson). They are often considered "living fossils."

Usage Examples

• Noun:
  • The family Limulidae includes all extant species of horseshoe crabs.
  • Scientists study the family Limulidae to understand arthropod evolution.

Advanced Usage

• In taxonomic hierarchy, family Limulidae is a formal classification rank.
  • The genus Limulus is placed within the family Limulidae.

Variants and Related Words

• Limulidae (n): The standard, unabbreviated form of the taxonomic family name.
  • Limulidae are not true crabs but are more closely related to spiders and scorpions.
• Limulid (n/adj): A member of the family Limulidae; pertaining to this family.
  • The limulid's blood is blue due to the presence of copper-based hemocyanin.

Synonyms

• Horseshoe crab family: A common descriptive synonym.
  • The horseshoe crab family has survived for hundreds of millions of years.

Related Terms (Not Phrasal Verbs or Idioms)

• Merostomata: The class to which the family Limulidae belongs.
• Xiphosura: The order often used synonymously with Limulidae in some classifications.
• Limulus: The best-known genus within this family (e.g., , the Atlantic horseshoe crab).

Noun

1. horseshoe crabs