The sea urchins of the Gulf of California live between the coasts of the Baja California Peninsula to the west and mainland state of Sonora, Mexico to the east. The northern boundary is the lateral band of land with the remains of the Colorado River Delta, and the southern is the Pacific Ocean. The Gulf of California is known for its high diversity and endemism of biota. One type of marine animal that can be found in this region is the sea urchin (class echinoidea, in the phylum echinodermata). One echinoid, , is a sea urchin endemic to the Gulf of California.
