Paracme

Paracme (pronounced par-AK-mee) refers to the period in the geological timescale following a metacme (the period of maximum abundance of a particular fossil species) when the abundance of that fossil species declines. It represents the waning phase of a species' dominance within a particular environment or geological stratum. Essentially, it marks the time after a species has reached its peak abundance and begins to become less common in the fossil record. The paracme is an important concept in biostratigraphy, helping geologists correlate rock layers and understand the relative ages of different sedimentary deposits. It is one phase in a cyclical pattern of abundance and scarcity for a particular species within the fossil record and contributes to understanding evolutionary trends and environmental changes.