Can baryonic features produce the observed 100 h-1 Mpc clustering?

We assess the possibility that baryonic acoustic oscillations in adiabatic models may explain the observations of excess power in large-scale structure on 100 h(-1) Mpc scales. The observed location restricts models to two extreme areas of parameter space. In either case, the baryon fraction must be large (Omega(b)/Omega(0) greater than or similar to 0.3) in order to yield significant features. The first region requires Omega(0) less than or similar to 0.2 h to match the location, implying large blue tilts (n greater than or similar to 1.4) to satisfy cluster abundance constraints. The power spectrum also continues to rise toward larger scales in these models. The second region requires Omega(0) approximate to 1, implying Omega(b) well out of the range of big bang nucleosynthesis constraints; moreover, the peak is noticeably wider than the observations suggest. Testable features of both solutions are that they require moderate reionization and thereby generate potentially observable (similar to 1 mu K) large-angle polarization, as well as subarcminute temperature fluctuations. In short, baryonic features in adiabatic models may explain the observed excess only if currently favored determinations of cosmological parameters are in substantial error or if present surveys do not represent a fair sample of 100 h(-1) Mpc structures.