Asterozoa
![](/Images/godic/202412/22/Haeckel_Ophiodea5548.jpg")
![Starfish fossil, Riedaster reicheli](/Images/godic/202412/22/Riedaster_reicheli5549.JPG")
![Ophiopetra lithographica from the Lower Hienheim Beds (Lower Tithonian, Upper Jurassic) near Regensburg, Germany](/Images/godic/202412/22/Ophiopetra_lithographica_aboral_larger_0108135549.jpg")
The Asterozoa are a subphylum in the phylum Echinodermata. Characteristics include a star-shaped body and radially divergent axes of symmetry. The subphylum includes the two classes Asteroidea, the starfish, and Ophiuroidea, the brittle stars and basket stars, and the extinct order Somasteroidea.