relicta

Relicta is a term borrowed from Latin (relictus, left behind) used primarily in biology to describe populations or species that persist from a former, more widespread lineage. Relicta denotes a relic, a lineage or population that has survived while related groups have become extinct or disappeared in other regions. The concept highlights historical biogeography and helps explain patterns of species distribution.

In practice, relicta refers to organisms that occupy limited geographic ranges and often represent ancient lineages. They may persist in refugia—stable or isolated habitats that shield them from broader climatic changes. Relict populations can display reduced genetic diversity and unique adaptation to their local environment, but they are not inherently more primitive or less evolved than their relatives.

Examples of well-known relicts include the coelacanth (Latimeria chalumnae), the ginkgo tree (Ginkgo biloba), the tuatara (Sphenodon punctatus), and the dawn redwood (Metasequoia glyptostroboides). These species serve as windows into past ecosystems and help researchers reconstruct historical biogeography and climate.

In taxonomy, relicta can appear as a descriptive epithet in species names to signify a presumed relic status, though it is not a formal taxonomic rank. Conservation attention often focuses on relicta species because their restricted ranges make them vulnerable to environmental change and habitat loss.