  Biskup et al. [Phys. Rev. Lett. 84 (2000) 4794] have recently suggested that
the loci of partition function zeroes can profitably be regarded as phase
boundaries in the complex temperature or field planes.
  We obtain the Fisher zeroes for Ising and Potts models on non-planar
(``thin'') regular random graphs using this approach, and note that the locus
of Fisher zeroes on a Bethe lattice is identical to the corresponding random
graph. Since the number of states appears as a parameter in the Potts solution
the limiting locus of chromatic zeroes is also accessible.
