Btw, Tsintaosaurus may be dominant at Laiyang.
I thought only one or two specimens were known?
If it is a parasaurolophine, the apparently Djadokhtan or Campanian beds there may have a faunal composition quite similar to Jiayin. I think that is consistent with a preNemegtian age for the latter. Jiayin may be younger than Laiyang but not by very much-maybe basal/early Maastrichtian.
To me this looks like a pyramid of weakly supported hypotheses.