The experimental value the muon g-2 is 4.2 sigma larger than the Standard Model prediction, when the hadronic vacuum polarization contribution (HVP) is determined from the measured R-ratio, and the HVP calculated in lattice QCD significantly exceeds the measured R-ratio value by a similar margin.  A review of existing e+e experiments reveals that the contribution of certain types of hadronic final states would not have been counted, due to the event selection and trigger requirements of experiments to date.  The lattice HVP and g-2 discrepancies are shown to naturally be explained by an undetected contribution to e+e—> hadrons from production of previously unidentified neutral, long-lived hadrons.  Preliminary results of an analysis of BES data on e+e- -> mu+mu- (in collaboration with Changzheng Yuan and Marek Karliner) support this interpretation.  Potential candidates for the new hadrons and experimental tests will be discussed.

There are favorable cosmological and astrophysical impacts of Dark Matter having hadronic interactions, which can be discussed if time permits.