Contribution of Interdisciplinary research project COPS to paper published in Journal of Biogeography: Biogeographic mechanisms involved in the colonisation of Madagascar by African vertebrates.

The publication of the article “Biogeographical mechanisms involved in the colonisation of Madagascar by African vertebrates: rifting, rafting and runways.” in the Journal of Biogeography on 9th December 2020 is the perfect example of the culmination of an interdisciplinary research project supported by ISblue.

Initiated within the framework of LabexMer (now ISblue), the collaboration between the themes of research for ocean and climate regulation (Theme 1) and ocean-earth regulation (Theme 2), contributed to this original publication on the colonisation of Madagascar by mammals.

The specific project “Ocean currents of the past and sedimentary deposits” allowed this collaborative research work involving Daniel Aslanian (REM), Thierry Huck (LOPS), Marina Rabineau (LGO) et Yurui Zhang (postdoc funded by LabexMer/ISblue, Ifremer and UBL University).

This publication presents an estimate of the travel time between Africa and Madagascar using the LOPS lagrangian software Ariane and currents from the Eocene paleoclimatic model  (55 million years ago) of the LSCE, to refute the hypothesis that small lemur-like mammals were able to survive such a long voyage on a floating raft (estimated at 60-70 days). LGO / REM researchers suggest that they were able to cross from island to island thanks to Davie ridge, which was about to emerge at the time.

Past and present physiographic maps of the Mozambique Channel
Past and present physiographic maps of the Mozambique Channel. Observations indicate three episodes of subaerial exposure: (a) Late Cretaceous–Early Palaeocene (66–60 Ma), (b) latest Eocene–Rupelian (36–30 Ma), (c) Late Serravallian–Messinian (12–05 Ma), while (d) shows present‐day bathymetry. Animals portrayed in the top left hand corners of a, b and c may have colonised Madagascar at this time.

Authors : Masters, Judith C., Fabien Génin, Yurui Zhang, Romain Pellen, Thierry Huck, Paul Mazza, Marina Rabineau, Moctar Doucoure, Daniel Aslanian, 2020: Biogeographic mechanisms involved in the colonisation of Madagascar by African vertebrates: rifting, rafting and runways. Journal of Biogeography, (JBI-20-0163), in press, doi: 10.1111/jbi.14032.  
https://doi.org/10.1111/jbi.14032