# Acanthopteri

CEFR C2 · Noun

Source: https://englishreference.com/word/acanthopteri
Updated: 2026-08-15

## Definition

a group of extinct fish that lived in the ocean millions of years ago. They had a unique body shape and were related to modern sharks and rays.

For teachers: an extinct order of marine fish characterized by a flattened body and a unique skeletal structure. Often referred to as 'spiny sharks' due to their distinctive dorsal spines.

## Examples

- Scientists study the fossils of acanthopteri to understand ancient marine life.
- The discovery of acanthopteri remains in the deep-sea trench provided new evidence about the evolution of early cartilaginous fish.
- While acanthopteri are no longer present in the modern ocean, their skeletal adaptations offer a critical link in the evolutionary history of modern sharks and rays.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.