On the use of extant Middle-East mangroves as modern analogues for Miocene Mediterranean-Paratethyan mangroves

Abstract During the Miocene Climatic Optimum (MCO; 17–15 Ma), the northern boundary of mangroves–now situated at ~30° N–extended along the northern Mediterranean-Paratethyan (M-P) coasts (~45° N). These Avicennia -only mangroves have been considered impoverished mangroves controlled by the general latitudinal temperature gradient. They have also been compared with the extant Middle East (ME) mangroves around the Arabian Peninsula, characterised by the dominance of Avicennia and their low diversity. However, these extant communities are not a latitudinal feature but rather an anomaly shaped by extreme environmental conditions (aridity, hypersalinity, sediment supply) that only a few mangrove species can tolerate. In contrast, reconstructed palaeoenvironments for MCO M-P mangroves indicate mild rainy climates. Currently, Avicennia (represented by A. marina ) is mainly tropical and its latitudinal boundaries are characterised by warm-temperate, humid climates with frost-free mild winters. We conclude that current ME mangroves cannot be considered modern analogues for the MCO M-P mangroves. Finding such modern analogues is challenging, and further studies are recommended to uncover their ecological and biogeographical patterns.