Pentasteria is an extinct genus of sea star that lived from the Early Jurassic to the Early Cretaceous. Its fossils have been found in Europe.
The Land Before Time
A small group of Pentasteria, or "star swimmers", is seen in The Land Before Time IX: Journey to Big Water when Mo shows Littlefoot the group of starfish sitting on a rock. Another group appears later on in the movie when Mo is showing Littlefoot his home.