The paper by Spocter et al. is an interesting and important contribution to a growing literature on the effects of domestication on the brain. The quantification of gyrification and analyses are appropriate and well described, but I do have a few questions about the dataset. In addition, I have a few comments about the Discussion. Detailed comments are provided below.

Lines 120-122. The section devoted to the Hecht et al. study needs to be expanded. Although the focus of Hecht et al. was breed variation more than domestication, a couple of sentence explaining their results is needed here because it is an important contribution to the study of canid brains and relied upon structural MRI.

Lines 123-137. Most of the discussion here seems to focus on scaling principles, but are there functional reasons for the gyrification index (GI) to differ within and among canids?

Line 142. Correction to “onne”

Line 143. Correction to “varietie”

Specimens. Of the wild canids, can the authors please indicate how many were truly wild versus those raised in captivity. This is potentially important as there is some evidence that captive breeding alone can change brain size and morphology and housing conditions can exert a significant effect on neuron numbers and morphology.

Line 203. Correction to “heterogeneity”

Line 223. Change “build” to “built”

Lines 337-338. I could not find details in the Methods as to how the confidence and prediction intervals were calculated. Is this derived from an OLS or PGLS approach?

Line 368. Correction to “mater”

Line 370. This would better if the comment in parentheses began with “That is” as a separate sentence.

Line 408. Change to “dogs”

Line 409. The dog breeds should be written as “Dachshund” and “Vizsla”

Line 411. Correction to “reducion”

Discussion 4.2. Is it possible to comment on whether there were any dwarf or brachycephalic breeds that did not adhere to the general allometric scaling for dogs/canids? I understand from Table 1 that the majority of dogs sampled were mixed breed, but presumably there is enough information to determine if they could still be considered miniature/teacup/dwarf or brachycephalic. Both miniaturized or brachycephalic breeds could be expected to deviate from that of more typical breeds.

Line 478. Delete “has been shown to” and change to “scales”

Line 479. Should be “large-brained”

Lines 508-526. Is the fox-like pattern simply due to brain size? Only two foxes were examined in the current study, one of which is particularly small, and with n = 2, how confident are the authors that this is a true differentiation of brain types within canids?

Lines 530-532. Within this section is the intent to only discuss species within the genus Vulpes? Otocyon is thought to be a close relative of Vulpes and is far more social. One might then expect it to differ from other species within Vulpini in brain anatomy.

Line 556. please include the scientific name for the dhole.

Line 558. I would limit this to the bush dog and perhaps discuss Otocyon or some species that occasionally hunt/feed in pairs or social groups (e.g. Nyctereutes, Cerdocyon). The dingo is realistically another dog, despite recent claims among some Australian researchers that it should be declared a separate species.

Discussion 4.4. It is interesting that the OCC GI was lower in dogs given the relative importance of visual communication between dogs and humans. I think the authors would benefit from discussing this briefly within the Discussion. That is, if the OCC has less folding, how do dogs process visual signals received from humans when hunting or engaging in other interactive behaviours?

Figures. The resolution of most of the figures was too low to see them effectively. This was especially true of Figure 7.

The authors have addressed all of my concerns. I am confident that this will prove to be a valuable contribution to our understanding of carnivoran brains and the effects of domestication on the mammalian brain.