osteostracan

Thân thiện

An osteostracan swims near the seafloor in a Devonian reef.

Definition

1. Noun:
   • An extinct jawless fish of the Devonian period with an armored head: An "osteostracan" is a member of an extinct group of early, jawless vertebrates characterized by a bony, shield-like head armor.

Usage Examples

• Noun:
  • The fossil record shows that the osteostracan was a common aquatic organism during the Devonian period.
  • Scientists study the head shield of the osteostracan to understand early vertebrate evolution.

Advanced Usage

• In paleontological classification: The term "osteostracan" is used to refer to any member of the subclass Osteostraci.
  • Osteostracans are considered a sister group to jawed vertebrates.

Variants and Related Words

• Osteostraci (n): The scientific subclass name for this group of extinct jawless fishes.
  • Osteostraci is a key taxon for studying the origin of paired fins.

Synonyms

• Cephalaspid: A common synonym referring to the same group of extinct armored jawless fishes.

Different Meanings

• This word has a single, specific meaning in paleontology and evolutionary biology. It does not have common idiomatic or figurative uses.

Học thuật

Noun

1. extinct jawless fish of the Devonian with armored head

Từ đồng nghĩa

• cephalaspid