Their methodology in the PDF link reads like an opinion poll and the whole bit about species is a side issue in the paper - they are really looking at mitochondrial DNA: Why should mitochondria define species?
I'm beginning to suspect "junk science"...?
PIF: "...they are really looking at mitochondrial DNA: Why should mitochondria define species?"
I'd assume mitochondrial DNA is easier to work with than nuclear DNA, thus quicker to accumulate a database on 100,000 species.
My guess is that others are doing similar, but more detailed full-DNA studies, which will perhaps give more granularity to these very vague conclusions.