fossilrich

Fossilrich is an informal descriptor used primarily in paleontology and geology to denote a site, layer, or rock unit that contains a high abundance of fossils. It is not a formal geological term or a named stratigraphic unit, but it appears in field notes, reports, and popular science writing to indicate a high yield of fossil material.

Fossil-rich deposits are typically the product of favorable conditions for fossilization, such as rapid burial, low oxygen, and sedimentation in calm environments. They are most commonly found in sedimentary rocks, including shales, limestones, sandstones, and mudstones. In some cases, they correspond to Lagerstätten, where exceptional preservation yields a wide array of fossils.

Researchers study fossil-rich sites to document biodiversity, track evolutionary change, and reconstruct ancient ecosystems. Field work often involves careful excavation, screen-washing, matrix dissolution, and sometimes non-destructive imaging. The value of fossil-rich sites also raises ethical considerations, including legal restrictions on collection, the need for curation in museums, and responsible sharing of location data to protect sites from looting.

Examples of widely cited fossil-rich sites include well-known Lagerstätten such as the Burgess Shale and Solnhofen Limestone, as well as abundant assemblages in formations like the Hell Creek and Florissant Beds. The term underscores the practical importance of sites with abundant preserved remains for both scientific study and education. Related concepts include fossiliferous deposits and Lagerstätten.