Abstract
<jats:p>Mangroves are pantropical intertidal forests that maintain coastal biodiversity, provide a wide range of ecological services and represent the most efficient blue-carbon ecosystems for mitigating global warming. A recent global initiative aims to reconstruct the historical biogeography of mangroves using comprehensive paleobotanical datasets from biogeographically coherent regions. This approach has been applied to the Caribbean, Europe, the Middle East and western Africa. Here, the same methodology is used to investigate the paleobiogeography and evolution of Southeast African (SEAF) mangroves, including those of the Western Indian Ocean (WIO) islands. Unlike previous regional syntheses, which reconstructed mangrove history from the Late Cretaceous onward, the SEAF dataset contains only Middle-Late Pleistocene records, with no confirmed Cretaceous, Paleogene or Neogene occurrences. This pattern is consistent with molecular phylogeographic studies of SEAF true-mangrove taxa, which indicate that they originated and diversified in the Eastern Indian Ocean (EIO) before expanding into SEAF mainly during the Late Pleistocene. A comparable Cenozoic fossil gap has also been reported for the Madagascar fauna, suggesting that this pattern reflects a genuine biogeographical feature rather than methodological bias or an incomplete fossil record. If confirmed, SEAF mangroves would represent the youngest known mangroves worldwide by more than 70 million years. This finding challenges the assumption that major mangrove regions share a common Late Cretaceous–Cenozoic history and opens new perspectives on the assembly and evolution of tropical coastal biotas. Future work should focus on expanding the fossil record and improving the chronological calibration of molecular phylogenies.</jats:p>