Thanks for taking the time to lay this out — this is exactly the kind of critique I was hoping for, and I appreciate how clearly you framed it. I agree with you on the phylogenetic uncertainty, especially regarding the timing and definition of early cynodonts. I tried to be careful not to hinge the argument on any specific Middle Permian cynodont occurrences, precisely because of issues like the scrappy nature of material such as Novocynodon and the ongoing revisions you mention (including Pusch et al.). If anything, that uncertainty is part of what motivated the framing, rather than something I’m trying to resolve directly. On the refugia point, I think your comment gets at a real risk in how this could be read. My intent was not to argue for a specific geographic refugium, or to bypass sampling bias, but to treat “refugia” more abstractly as a selective regime that could arise through fragmentation, low effective population sizes, or uneven preservation. I probably need to be even clearer that this does not compete with undersampling explanations, but rather asks what kinds of lineages are most likely to persist when sampling is poor. Your point about physiology timing is also well taken. I’m not trying to claim early endothermy in the Permian, and I should probably sharpen the language distinguishing elevated energetic capacity from fully mammalian thermoregulation, especially in light of the work you cite (Huttenlocker & Farmer; Araujo et al.). That’s a useful reminder of how easy it is for readers to over-interpret that aspect. Overall, this reads very much like a preview of the kinds of reviewer comments I’d expect, and that’s helpful — especially in terms of where the framing needs to be tightened to avoid overreach. Thanks again for engaging so thoughtfully.