Triaxial strongly deformed bands in Tm160,161

High-spin states in Tm-160,Tm-161 were populated using the Te-128(Cl-37, 5n and 4n) reactions at a beam energy of 170 MeV. Emitted gamma rays were detected in the Gammasphere spectrometer. Two rotational bands with high moments of inertia were discovered, one assigned to Tm-160, while the other tentatively assigned to Tm-161. These sequences display features similar to bands observed in neighboring Er, Tm, Yb, and Lu nuclei which have been discussed in terms of triaxial strongly deformed structures. Cranked Nilsson Strutinsky calculations have been performed that predict well-deformed triaxial shapes at high spin in Tm-160,Tm-161.