Ancient Marine Life

noun a genus of flightless aquatic birds that lived during the Late Cretaceous period

• The hesperornis is an extinct aquatic bird that lived during the Late Cretaceous period.
• Have you heard of the hesperornis? It was like a prehistoric penguin!
• Dude, that hesperornis was one cool bird from back in the day.
• The hesperornis was a true pioneer of the ancient seas, navigating its way through unknown waters.

noun a class of extinct jawed fishes that lived from the Silurian to the Permian period

• The acanthodian fish lived during the Silurian and Devonian periods.
• Have you heard of those acanthodian fish that lived millions of years ago?
• Those acanthodian fish were like the rockstars of the ancient seas.
• Her sharp wit was like the spines of an acanthodian fish, always ready to defend her arguments.