The data available for short-lived p-nuclides are used in an open nonlinear model of the chemical evolution of the Galaxy in order to discuss the origin of extinct radionuclides, the stellar sources of p-nuclides, and the chronology of solar system formation. It is concluded that the observed abundances of 97Tc, 98Tc, 92Nb, and 146Sm in the early solar system are consistent with nucleosynthetis in type II supernovae during continuous chemical evolution of the Galaxy and a subsequent short isolation of the presolar molecular cloud from fresh nucleosynthetic inputs. However; further work on supernova models is needed before p-radionuclides will comprise reliable cosmochronometers. Despite these limitations, we argue that niobium-92 can be used to test whether the rp-process contributed to the synthesis of light p-nuclides in the Mo-Ru region.