  A Large Quasar Group (LQG) of particularly large size and high membership has
been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has
characteristic size (volume^1/3) ~ 500 Mpc (proper size, present epoch),
longest dimension ~ 1240 Mpc, membership of 73 quasars, and mean redshift <z> =
1.27. In terms of both size and membership it is the most extreme LQG found in
the DR7QSO catalogue for the redshift range 1.0 <= z <= 1.8 of our current
investigation. Its location on the sky is ~ 8.8 deg north (~ 615 Mpc projected)
of the Clowes & Campusano LQG at the same redshift, <z> = 1.28, which is itself
one of the more extreme examples. Their boundaries approach to within ~ 2 deg
(~ 140 Mpc projected). This new, huge LQG appears to be the largest structure
currently known in the early universe. Its size suggests incompatibility with
the Yadav et al. scale of homogeneity for the concordance cosmology, and thus
challenges the assumption of the cosmological principle.
