Abatus cordatus is a species of sea urchin in the family Schizasteridae.

It is native to shallow seas surrounding certain island groups in the southern Indian Ocean.

[3] Abatus cordatus is endemic to certain subantarctic island groups in the southern Indian Ocean.

It is not clear precisely when the eggs are fertilised, but it has been discovered that the juveniles do not necessarily all share the same father.

Their lack of ability to disperse may make them sensitive to alterations in their habitat such as changes in seawater temperatures.