Fósseisguia

Fósseisguia is a term used in paleontology and stratigraphy to describe a fossil species or assemblage that serves as a reference marker for correlating rock layers and estimating their relative ages. The term combines elements of fossil and guide, reflecting its function as a navigational aid within the geological timescale. Although not a formal taxonomic category, fósseisguia emphasizes fossils that are easy to recognize, widely distributed, and temporally restricted enough to help align strata from different locations.

Role and criteria

A fossil designated as a fósseisguia should have a recognizable morphology, a broad geographic distribution, and a relatively short, well-defined stratigraphic range. Preservation potential and the ability to be identified in the field or lab are important. In practice, fósseisguia overlaps with the broader concept of index fossils, which are used to identify specific intervals of geological time and to synchronize rock sequences across regions.

Applications

Fósseisguia are used in stratigraphic mapping, biostratigraphy, and resource exploration, where accurate dating and correlation improve the reconstruction of depositional environments and the planning of surveys or drilling programs. They also aid in paleoecological studies by providing time stamps for environmental changes recorded in the fossil record.

Limitations

The usefulness of a fósseisguia can be affected by reworking, diagenetic alteration, or regional variations in fossil distribution. Careful consideration of taphonomy and regional stratigraphy is required to avoid misinterpretation.

See also

Index fossil, biostratigraphy, stratigraphy, correlation.