Shape changes in ${}_{}{}^{79}{}_{}{}^{}\mathrm{Kr}$

High-spin states in ${}_{}{}^{79}{}_{}{}^{}\mathrm{Kr}$ were studied using the ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$${(}^{18}$O,p3n) reaction at 65 MeV at the Florida State University Tandem-LINAC facility. Prompt γ-γ coincidences were observed using the Pitt-FSU detector array. Twelve new states were found, along with 19 new transitions. The yrast positive- and negative-parity bands were extended up to spins of (45/$2^{+}$) and (31/$2^{\mathrm{-}}$), respectively. Spin assignments were made based on directional correlation of oriented nuclei ratios whenever possible. A cranked-shell-model analysis shows some indication for a second band crossing in the positive-parity band at ħω≊0.75 MeV. This crossing, probably due to an aligned ${\mathit{g}}_{9/2}$ neutron pair, occurs with a much larger band interaction than the first ${\mathit{g}}_{9/2}$ proton crossing. An increase in signature splitting above ħω≊0.75 MeV and a return of large alternations in the B(M1)/B(E2) ratio is consistent with the theoretically predicted return to a nearly oblate shape.