Red algae, architects of Tenerife’s Pleistocene coast

PUBLICATION — Johnson, M.E., Martín-González, E., Sansón, M., Uchman, A., Ramalho, R.S., Baarli, B. G., Madeira, J., Madeira, P., Stolarski, J., Ávila, G.C., Ávila, S. P. 2026.  Encrustations dominated by crustose coralline algae on coastal boulders from the last interglacial epoch at Tachero on Tenerife (Canary Islands). Facies 73, 2 (2027). https://doi.org/10.1007/s10347-026-00753-5

Figure: Basalt boulder with a thick crustose coralline algal biocrust at Tachero, Tenerife (top), and a cross-section through the biocrust containing fragments of the coral Cladocora ?debilis (bottom; arrows).

A fossilized Tenerife shoreline from the last interglacial
Basalt boulders on Tenerife preserve a remarkable record of a coastal ecosystem from about 125,000 years ago. Crustose red algae formed coatings up to 20 cm thick, creating habitat for gastropods, bivalves, echinoids, and corals over centuries. This exceptional archive reveals how life was organized along a rocky shore in a warmer Pleistocene world.