We briefly argue that the fermion mass hierarchy points toward a class
of extensions of the Standard Model gauge group which has received sc
ant attention in the literature. The members of this class are charact
erised by having the same irreducible representations as exist in the
Standard Model and by having the Standard Model embedded within them a
s a diagonal subgroup. The anomalies of the new mass protecting gauge
quantum numbers cancel amongst the Standard Model quarks and leptons a
lone, and we analyse how well some specific groups can naturally produ
ce the hierarchies of fermion masses and mixing angles, at least order
of magnitude wise.