The fossil localities of the Piedra Chamana Fossil Forest (Eocene, Peru): a prospectus for research and conservation

Woodcock D.; Allen S.E.; Terry D.O., Jr.; Yeago J.; Jaramillo C.; Marulanda S.G.; Rufasto E.; Medina L.M.T.; Prado Y.; Meyer H.W. · Acta Palaeobotanica (2026) · DOI: 10.35535/acpa-2026-0001

Resumen

The fossil plants of the Piedra Chamana Fossil Forest in northern Peru occur in volcaniclastic rocks of the Huambos Formation dated at 39 Ma (late Middle Eocene). Studies to date have focused on the fossil leaves and woods in ashfall and overlying ashflow tuffs near the town of Sexi. Additional fossiliferous strata occur in tuffs and sedimentary deposits over a large area near Sexi and the adjacent community of Cunyac. These largely unstudied fossil exposures include locations with in situ vertical trees in growth position associated with paleosols. The paleoflora, dominated by taxa related to lowland Amazonian clades and including a few Asian components and a mangrove, suggests a seasonally flooded lowland tropical forest and more dry-adapted interfluvial vegetation growing under warm conditions. Associated paleosols also suggest distinct wet-dry cycles as they are highly weathered with mottling and show evidence of freshwater influence, landscape heterogeneity, and intense weathering. At present, the integrity of the fossil sites is compromised by mining, illegal collecting, and inadequate site protections, all of which have contributed to a significant loss of fossil material. Conservation and protection of these important paleontological sites and their development as a resource for education and tourism will benefit both science and the local community. © The Author(s) 2026.

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Nacional Pedro Ruiz Gallo