What is Ethiopian amber telling us about Miocene African forest ecosystem?
Résumé
The amber fossil record is distributed worldwide but mainly supported by Northern Hemisphere deposits.The Southern Hemisphere amber fossil record is relatively scarce, due to difficulties of access andprospection. The African continent recently revealed two new amber outcrops. Previously, fossiliferous andnon fossiliferous copals were known from Africa, as well as older fossilised resins lacking fossil inclusions1.The Cretaceous resin from Congo, and the Cenozoic resin from Ethiopia, are the first African ambers knownto display arthropod and botanical inclusions.When first mentioned in 20102, the Ethiopian amber was suggested Cretaceous. This dating was rapidlyquestioned by the modern lineage taxa, described from the fossilized resin3,4. Those rather display a Cenozoicassemblage. Palynological data and field observations corroborate this revision and further indicate aMiocene age of the amber. The resin originates from an angiosperm, probably Hymenaea (Fabaceae), assuggested by its chemical signal, and the associated botanical inclusions. Cryptogam and arthropod inclusions(mainly Hymenoptera and Diptera) already display a large diversity of modern taxa. All together, fossilisedspecimens illustrate a subtropical, hot and humid, swamp forest ecosystem. Similarities with the botanicaland entomofaunal composition of the contemporaneous Dominican and Mexican ambers, suggest anaffinities between African and American Miocene ecosystems.References1. Bouju V., Perrichot P. 2020: BSGF Earth Sci. Bull., 191 (17); doi:10.1051/bsgf/20200182. Schmidt A.R. et al. 2010: Proc. Natl Acad. Sci. U.S.A., 107 (16), 7329 7334; doi:10.1073/pnas.10009481073. Coty D. et al. 2016: Ann. Soc. entomol. Fr., 52 (3), 161 166; doi:10.1080/00379271.2016.12304774. Perrichot V. et al. 2016: The age and paleobiota of Ethiopian amber revisited, in 5th InternationalPaleontological Congress.