AUTHORS’ CONTRIBUTION
S.F. is the project leader. S.F., D.S., A.B., G.L. and S.M. were
responsible for experimental and project design. S.M. was responsible
for samples collection. A.S. performed some of the experiments. A.B. and
S.M. performed most of the experiments and calculations. S.M. prepared,
sorted and packaged the samples for shipment from Nigeria to France.
S.F., D.S., G.L., A.B. and S.M. made conceptual contributions.