Entry #88

In paleontology, the phenomenon is described as species that have disappeared from the fossil record for one or more periods of time only to reappear later as fossils or living organisms. Conservation biology and ecology define it as species or populations that were thought to be extinct and were rediscovered alive after a period of time. Scientists debate the causes of the Lazarus taxa with explanations ranging from the refugia theory (biological) to sampling failure (stratigraphic). Refugia describes Lazarua taxa as having found areas of shelter that protected populations during environmental crisis, allowing re-emergence into the surrounding area afterwards. Sampling failure argues that the taxa only "disappeared" because of inadequate data collection. Examples of paleonological taxa include the Coelacanth (Latimeria) which was rediscovered in 1938 after being thought to be extinct due to its absence from the fossil record 66 million years ago. Species from the International Union for Conservation of Nature's (IUCN) red list that have reappeared include the New Caledonian Crested Gecko (Correlophus ciliatus) first described in 1866 and thought extinct unil 1994.