acanthad
n. C2 Proficiency acan·thad
n. a type of ancient fish that lived in the ocean millions of years ago. It had a unique body shape and lived in the deep sea.
n. a group of extinct marine fish from the Silurian and Devonian periods, characterized by a distinctive body shape and a lack of jaws.
The acanthad is an ancient fish with no jaws.
Fossils of the acanthad have been found in deep-sea sediments, providing insight into early vertebrate evolution.
The acanthad represents a critical link in the evolutionary history of vertebrates, as it possessed a notochord but lacked the jaw structures seen in later fish species.