So what is the upper bound when the DMME shows in the fossil record?
The first appearance of the DMME in the fossil record, it can have evolved no later than that, although obviously if we are talking about 2 separate lineages where the trait evolves independently then its a bit more complex.
The earliest know mammalian fossil with a DMME is, I think, Hadrocodium (
Luo et al., 2007). Hadrocodium is dated at ~195 MYA, but even before then the earliest instance of the DMME was at ~150 MYA, still well before your Yanoconodon date of 125 MYA.
And it was a "transitional before the DMME
This is not supported from the original paper or from the Wikipedia article. In fact looking at the wikipedia article you lined to I have to ask if you even bothered to actually read it? It says right there in the wiki ...
Wikipedia writes:
In the lineage most closely related to mammals, the jaws of Hadrocodium (about 195M years ago in the very early Jurassic) suggest that it or a very close ancestor may have been the first to have a fully mammalian middle ear
So do you understand what a transitional fossil is yet? As I pointed out right at the start all it means is that it shows an intermediate morphology in terms of the middle ear between modern mammals and their early mammaliaform ancestors, not that it is itself necessarily an ancestral species to modern mammals.
Therefore we can have an 'intermediate fossil' appear in the fossil record well after the first instance of the trait it is an intermediate stage to.
To reiterate ... it
was a transitional but for all we know it was extant
after the DMME was already established in the mammalian lineage.
So from 70mya or so all or most mmamals have the DDME. Correct?
From considerably before that although related mammaliaforms, such as Yanoconodon, obviously still showed the transitional middle ear morphology at later times.
So did it appear between 125 and 70 mya or would this be a prediction of ToE.
No and no. What the evolutionary theory did predict was that such an intermediate form would exist. When it is actually found in the fossil record is relatively immaterial.
TTFN,
WK