noun
- A member of an extinct group of lobe-finned fishes that lived from the Devonian period onward and are considered ancestors of tetrapods.
Usage: paleontology; biology
adjective
- Relating to or denoting crossopterygians or their characteristics, especially the fleshy, lobed fins.
Usage: paleontology; biology
Examples
- Crossopterygians were among the first vertebrates to develop limb-like structures.
- The crossopterygian fish possessed muscular, lobed fins that could support movement on land.
- Scientists believe crossopterygians are the evolutionary link between fish and early amphibians.
- Fossil evidence shows that crossopterygian fins contained bones similar to those in tetrapod limbs.
- The crossopterygian group includes the coelacanth, a living fossil discovered in the Indian Ocean.