000162519 001__ 162519 000162519 005__ 20251017144640.0 000162519 0247_ $$2doi$$a10.1038/s41467-025-62189-9 000162519 0248_ $$2sideral$$a145090 000162519 037__ $$aART-2025-145090 000162519 041__ $$aeng 000162519 100__ $$aRadmacher, Wieslawa 000162519 245__ $$aOcean freshening near the end of the Mesozoic 000162519 260__ $$c2025 000162519 5060_ $$aAccess copy available to the general public$$fUnrestricted 000162519 5203_ $$aPaleogeographic changes have significantly shaped ocean circulation and climate dynamics throughout Earth’s history. This study integrates geological proxies with climate simulations to assess how ocean gateway evolution influenced ocean salinity near the end of the Mesozoic (~66 Ma). Our modeling results demonstrate that 1) Central American Seaway shoaling reorganizes ocean currents, and 2) Arctic marine gateway restrictions, confining Arctic–Global Ocean exchange exclusively to the Greenland–Norwegian Seaway, drive Arctic Ocean surface freshening and southward outflow of buoyant, low-salinity waters. However, only the combined effect of these two factors leads to both Arctic freshening and increased water mass stratification in the Greenland–Norwegian Seaway, proto-North Atlantic, and the Western Tethys. This scenario aligns with Maastrichtian palynological, micropaleontological, and geochemical records from high- and low-latitude sites. Our findings highlight the profound impact of these latest Cretaceous paleogeographic reconfigurations in altering global salinity patterns, underscoring their role as key drivers of global climate dynamics. 000162519 536__ $$9info:eu-repo/grantAgreement/ES/AEI/PID2022-136233NB-I00$$9info:eu-repo/grantAgreement/ES/DGA/E33-23R 000162519 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttps://creativecommons.org/licenses/by/4.0/deed.es 000162519 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000162519 700__ $$aNiezgodzki, Igor 000162519 700__ $$0(orcid)0000-0001-7302-5901$$aGilabert, Vicente 000162519 700__ $$aKnorr, Gregor 000162519 700__ $$aBuchs, David M. 000162519 700__ $$0(orcid)0000-0003-0063-8752$$aArz, José A.$$uUniversidad de Zaragoza 000162519 700__ $$0(orcid)0000-0003-4632-533X$$aArenillas, Ignacio$$uUniversidad de Zaragoza 000162519 700__ $$aPearce, Martin A. 000162519 700__ $$aTyszka, Jaroslaw 000162519 700__ $$aMikolajczak, Mateusz 000162519 700__ $$aVásquez, Osmín J. 000162519 700__ $$aAshckenazi-Polivoda, Sarit 000162519 700__ $$aAbramovich, Sigal 000162519 700__ $$aNiechwedowicz, Mariusz 000162519 700__ $$aMangerud, Gunn 000162519 7102_ $$12000$$2655$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Paleontología 000162519 773__ $$g16, 1 (2025), [15 pp.]$$tNature communications$$x2041-1723 000162519 8564_ $$s13841015$$uhttps://zaguan.unizar.es/record/162519/files/texto_completo.pdf$$yVersión publicada 000162519 8564_ $$s2552310$$uhttps://zaguan.unizar.es/record/162519/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000162519 909CO $$ooai:zaguan.unizar.es:162519$$particulos$$pdriver 000162519 951__ $$a2025-10-17-14:31:29 000162519 980__ $$aARTICLE