  Above-barrier fusion cross-sections for an isotopic chain of oxygen isotopes
with A=16-19 incident on a $^{12}$C target are presented. Experimental data are
compared with both static and dynamical microscopic calculations. These
calculations are unable to explain the $\sim$37\% increase in the average
above-barrier fusion cross-section observed for $^{19}$O as compared to
$\beta$-stable oxygen isotopes. This result suggests that for neutron-rich
nuclei existing time-dependent Hartree-Fock calculations underpredict the role
of dynamics at near-barrier energies. High-quality measurement of above-barrier
fusion for an isotopic chain of increasingly neutron-rich nuclei provides an
effective means to probe this fusion dynamics.
