In biology, a lazarus taxon (plural taxa) is a taxon that disappears from one or more periods of the fossil record, only to appear again later. The term refers to the Biblical figure Lazarus, who lived, died, and then was raised from the dead. Lazarus taxa occur because the fossil record is imperfect and contains gaps, particularly when the number of individuals in a taxon becomes very low. If these gaps are filled by new fossil discoveries, a taxon will no longer be classified as a Lazarus taxon.