Definitions

1. noun

A genus of fossilized marine reptiles related to the ichthyosaurs.

“The discovery of the new icosteus fossils shed light on the evolution of marine reptiles during the Triassic period.”

2. plural noun

Members of the genus Icosteus, a group of marine reptiles.

“Several icosteus specimens were found in the same fossil bed, giving paleontologists valuable insights into their behavior.”