RT Journal Article T1 Reconstrucción paleoambiental del tránsito Cretácico-Terciario en La Lajilla (México) con foraminíferos T1 Paleoenvironmental turnover across the Cretaceous-Tertiary transition at La Lajilla (México) based on foraminifera A1 Alegret, Laia A1 Arenillas, J. I. A1 Arz, José Antonio A1 Meléndez Hevia, Alfonso AB Upper Maastrichtian and lower Danian sediments belonging to the Méndez and the Velasco formations, respectively, contain abundant foraminifera at La Lajilla section (northeastern México). Foraminifera! turnover across the K/T boundary indicate a catastrophic mass extinction of planktic foraminifera, whereas benthic foraminiferal extinction do not exceed 25%. The most important change in benthic foraminifera across the KIT boundary consists of a reorganisation of their communities: infaunal morphogroups were more affected than the epifaunal ones. Most of the infaunal species became extinct or temporally disappeared, due to the lack of nutrient supply toward the sea bottom floor. Infaunal percentages increased after the boundary, and indicate primary productivity recovery at La Lajilla during the lower Danian PB Sociedad Geológica de España YR 2001 FD 2001 LK http://hdl.handle.net/10272/9719 UL http://hdl.handle.net/10272/9719 LA spa DS Repositorio Institucional de la Universidad de Huelva RD 30 may 2026