On the Incompleteness of the Coelacanth Fossil Record

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

This contribution is very interesting, but I would say on the principle only although a lot of work has already be done. The analysis of a complete and up-to-date fossil coelacanths database is indeed a source of interesting scientific trends and interpretations.

However, the proposed assumptions and postulates are often questionable.

For instance, assuming that a species has a life span equivalent to the time interval from the beginning to the end of the geological stage in which it was found is debatable. But it is unfortunately not discussed, and there especially is no development on the main trends neither on a case by case basis (see examples, but there are many others, on the cases of Garnbergia, Rhabdoderma or Shoshonia).

I provided comments on the entire attached document.

No doubt that the work already done is very important and that some elements are very interesting, but the interpretations are too succinctly developed and too little supported.

The outstanding database deserves to be better valued. It would be a shame to publish these first weakly supported trends, and therefore highly questionable due to the lack of development and (re)contextualization, while there is the potential of a beautiful article.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

General comments

Thank you for the opportunity to review this manuscript. It reviews Coelacanth taxonomy, distribution, and history, drawing on data from online platforms. This type of review is valuable; however, several aspects should be addressed before the manuscript can be accepted.

Firstly, I recommend including an image that illustrates both fossil and extant coelacanth species. Given that this manuscript is part of a special edition focused on extinctions, such visual representation would be particularly relevant and beneficial. Additionally, some of the supplementary material is not referenced in the main text and should be appropriately integrated. Lastly, the manuscript would benefit from a thorough revision of the English language to improve clarity.

Further comments regarding specific sections of the manuscript are provided below, along with annotations in the main text.

 

Introduction

I believe this section could benefit from the inclusion of additional information. For instance, providing more background on the history of taxonomy would be helpful. It might also be valuable to elaborate on the relatively limited systematic studies concerning the coelacanth fossil record, as referenced in lines 54 and 55. Furthermore, some explanation of the studies that did not sufficiently address sampling biases or systematically assess the quality of the coelacanth fossil record (lines 65 and 66) is recommended to strengthen the introduction. A clear articulation of these points seems essential to effectively support the rationale for reviewing this fish.

 

Material and methods

I agree that Google Scholar is a valuable tool for locating scientific publications. However, to ensure a more comprehensive review, I would also recommend consulting additional sources. Some references, such as printed books housed in non-indexed libraries or scientific works not available on academic platforms, may not be included in Google Scholar’s database. As a useful complement, I suggest exploring the Biodiversity Heritage Library (https://www.biodiversitylibrary.org/) and examining the reference lists of relevant papers.

Similarly, I would recommend exercising some caution in relying exclusively on the Paleobiology Database for the entire dataset. While this platform, like Google Scholar, is undoubtedly a valuable resource, it is not without occasional errors. I suggest verifying the information by consulting the original references cited within the database to ensure accuracy.

Finally, it would be helpful to provide more details on the parameters used in the rarefaction analysis and clarify which software, platform, or reference was employed to count valid species and construct the time-calibrated phylogenetic tree.

 

Discussion

The section Spatial and Temporal Assessment of Coelacanth Fossil Records shows a noticeable lack of discussion regarding previous studies on the subject. Incorporating a review of earlier work is essential to provide context and strengthen the foundation for the current analysis, particularly when discussing spatial and temporal distribution patterns.

The section Validity of Diversity Peaks is well-structured and informative. However, the content in the section Factors Contributing to Incomplete Coelacanth Fossil Records addresses general challenges associated with the fossil record as a whole, rather than issues specific to coelacanths. It may be helpful to clearly distinguish which factors are unique or particularly relevant to coelacanths to maintain a focused discussion.

 

Final considerations

                I consider that a review of coelacanths is not invalid. However, some points still need to be addressed before the final acceptance of this manuscript. For this, deep modifications are necessary in the structure of the manuscript. Therefore, my final decision is to reconsider the publication of the manuscript before major revisions.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors and editors,

I sincerely thank the authors for considering all my comments. I consider that the manuscript has been significantly improved.

Taking into account my last proposals for typographical corrections and my few comments (see yellow underlining in attached file), I consider that this contribution deserves to be accepted for publication.

I add that I have not received the Supplementary File S6 entitled "Continental species discovery timeline" as noticed at the end of the summary (in page 2 of the response to my comments), but I trust this S6 is useful and accurate.

Best regards,

 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you to the authors for thoughtfully addressing the suggestions and comments in the manuscript. Following the revision, the manuscript is now ready for publication. Please just remove the period on line 89 after “(Supplementary File 1)” and the one on line 96 after “fossil sites per unit area”. Thank you again for this interesting paper. I look forward to seeing it published soon. With best regards.

Author Response

For research article

Response to Reviewer 2 Comments

1. Summary

Thank you very much for the review and recognition of our paper. Your comments are extremely helpful to us. Thank you for your hard work and valuable suggestions! Wishing you all the best!

2. Point-by-point response

Q1: Please just remove the period on line 89 after “(Supplementary File 1)” and the one on line 96 after “fossil sites per unit area”

A1: The periods mentioned have been deleted.