Actually, it was me who said that, not Glenn, though I'm sure he would
agree with it. He does have a PhD in that field, after all. As for index
fossils, it is true that index fossils are used in the field to identify
strata, but only tentatively. There are methods that provide double
checks on it, of course. And, even if you were right about this, that
still doesn't make it just an "opinion". The use of index fossils is
based upon many decades of field work correlating fossils and strata and
this was work was done long before there were any evolutionary
assumptions to influence it.
Ed