The unusual yrast spectrum of /sup 158/Yb at very high spins is interpreted in terms of a band termination at I/sup ..pi../ = 36/sup +/. A similar spectrum with band terminations is obtained in microscopic cranking calculations for this nucleus. A basic element of the theory is that the finiteness of rotational bands is connected with a gradual shape change until the rotation takes place around a symmetry axis.