A Gliriform Tooth from the Eocene of the Erlian Basin (Nei Mongol, China) and the Premolar Morphology of Anagalidan Mammals at a Crossroads

Round 1

Reviewer 1 Report

This is a very nice paper describing a tooth that has intriguing characteristics found in both mimotonids and anagalids. I am always pleased when I see papers published in this fashion, describing an intriguing tooth, of which scholars should be aware.  My comments are minor and are superficial but I think the changes need to be strongly considered by the authors.  This paper should be published as soon as possible. 

I have one comment on the figure 2, D.  This image is very pixelated.  Is there any way to take another image?  If not, would it be more clear if the image was decreased in size?  Since the article will be distributed as a PDF, its easy for the view to zoom in on an figure if the picture is a bit smaller.  This should not be a reason to reject the paper,  but a better picture for 2D would be nice. 

I have some comments on the writing that the authors should consider. I have made my comments based on line number. My comments are based on refining either the anatomical description or the grammar/punctuation:

132 replace spiky with conical

133 replace distally with distal

135 replace element with feature

137-139 reword sentence "It resembles more closely the overall proportions of the cusp size relative to the whole dental surface in Anagalopsis and Hsiuannania." to: It resembles Anagalopsis and Hsiuannania more closely in the overall proportions of cusp size relative to the whole dental surface. --This rewording makes a stronger statement.

156 no comma after 'cingulum'

159 remove 'the' before conules

173 place comma after 'onward'

180 remove semi-colon after genera and replace with a period

206-208 Consider rewording sentence: "Such extensive dental wear indicates abrasive diet with great portion of dietary fibers, demanding long chewing, similarly as in duplicidentates, i.e., lagomorphs and larger mimotonids such as Gomphos or Mimolagus [26]."  to: Such extensive dental wear suggests an abrasive diet indicative of high fiber content, demanding long chewing, as seen in duplicidentates, i.e., lagomorphs and larger mimotonids such as Gomphos or Mimolagus [26]. 

Author Response

Point 1: I have one comment on the figure 2, D.  This image is very pixelated.  Is there any way to take another image?  If not, would it be more clear if the image was decreased in size? 

Response to Point 1: We agree and we replaced this image with another photograph of the same specimen. Now it is more clear.

We amended all other points as requested (concerning grammar/anatomical terms).

Reviewer 2 Report

The study describes and analyses an upper P4 of an anagalid from the Middle Eocene of the classic Huheboerhe site in Mongolia. Anagalids are enigmatic, not well understood gliriform mammals of the Paleogene, and every new report of this group is of interest. The new, semihypsodont tooth is morphologically intermediate between mimontonids (duplicidentates) and anagalids. It therefore adds new information on the diversity of anagalids of the Eocene and is worth to be published in Diversity.

The morphological analysis and description are adequate, correct, and clear. The illustrations (SEM images) of the P4 are of good quality. However, I suggest to turn the side view of the P4 by 180° in order to present it in the anatomically correct position.

I have made a number of annotations directly into the manuscript, mainly small linguistic issues. The abstract can be condensed a bit (see manuscript), and the last half-sentence of the abstract needs clarification. Following some issues which should be addressed by the authors:

Use of “basal” in connections with clades (e.g. “basal Euarchontoglires”): Although often used, the term “basal” is not quite correct in cladistics. Striktly spoken, there is not “basal” in a cladogram; in a cladogram there are only dichotomies, and one clade is not  “more basal” than its sister clade. Therefore the term “basal” should be avoided. I suggest to replace it by “early” or “primitive” (non-derived).

“Paraphyletic group”: I suggest to say “paraphyletic grouping”, in order to differentiate from “group” which usually is associated with monophyletic (natural group).

On page 4, line 112 you say that “…overall morphology of the crown resembles more that of larger anagalids…” [than to mimotonids]. It would be good to list here briefly the distinctive characters you refer to. In the text you compare the P4 with that of other anagalids and mimotonids, but it would be helpful to have the characters listed here that exactly make this tooth an anagalid.

To sum up, this is a worthwile contribution to the knowledge of the diversity of Palegeone mammals which I recommend to be accepted after minor revision.

Comments for author File: Comments.pdf

Author Response

Point 1: However, I suggest to turn the side view of the P4 by 180° in order to present it in the anatomically correct position.

Response to Point 1: we rotated the image, as requested.

We upload the file with our point by point responses to the Reviewer's remarks.

We carefully checked the text linguistically and amended, if appropriate.

Author Response File: Author Response.pdf