All reviews of published articles are made public. This includes manuscript files, peer review comments, author rebuttals and revised materials. Note: This was optional for articles submitted before 13 February 2023.
Peer reviewers are encouraged (but not required) to provide their names to the authors when submitting their peer review. If they agree to provide their name, then their personal profile page will reflect a public acknowledgment that they performed a review (even if the article is rejected). If the article is accepted, then reviewers who provided their name will be associated with the article itself.
Thank you for carefully responding to the reviewers concerns. I agree this has improved the manuscript and I have recommended Accepting the manuscript for publication. Please thoroughly review the page proofs, as that will be your last chance to make any typographical or grammatical corrections prior to publication.
[# PeerJ Staff Note - this decision was reviewed and approved by Kenneth De Baets, a PeerJ Section Editor covering this Section #]
All three reviewers agree that this is a good and useful analysis that requires minor revisions. Reviewer 2 provides the most extensive review with suggestions for added Tables and detailed suggestions to improve clarity of the manuscript. Please take their comments, as well as those from the other reviewers, to heart in revising your manuscript. There are many comments, but they should not be too difficult to address. I look forward to receiving your revisions.
I have a feeling that the language of this manuscript could be improved with the help of a native English speaker, whom I am not (see my comments on the attached PDF). I also think the abstract could be shortened. Apart from this, the litterature references are sufficient, the manuscript is well-structured and self-contained.
As far as I am aware, this reasearch is within the aim and scope of the journal, the research question is well defined and the investigation are rigorous. From time to time, however, I think that the methods are not sufficiently explained and could be a bit difficult to fully understand to a non-specialist like me (see attached PDF for more details).
All underlying data, as far I can judge, have been provided and the conclusions are clear and limited to supporting results.
This manuscript explores the trace element composition of fossil scales and teeth from the Devonian and Cretaceous using three complementary techniques, in an attempt to discern the relative impact of diagenesis on the tissues comprising these common types of vertebrate fossils. The manuscript is generally well written and well referenced. My uploaded PDF includes a number of very minor wording and phrasing recommendations aimed at improving clarity, plus a couple potentially useful citations the authors could consider checking out. A suitable Introduction is provided which helps readers to become familiar with the methods used and the process of postmortem trace element uptake by bioapatite. The figures are appropriate. I would strongly urge the authors to include a new table which shows the raw whole-specimen average concentrations of each analyzed minor and trace element, the sum REEs, and, if desired, a breakdown of these averages within each fossil specimen by tissue type (i.e., dentine, pulp cavity tissue, inner enamel, etc.). It is convention to include such a summary table in studies of REEs, and it would help clarify the magnitude of elemental enrichment the fossils have experienced.
The study employs three traditional methods in geochemical taphonomy, including cathodoluminescence, which to date has only rarely been used (to my knowledge) for the study of vertebrate fossils. Overall I would characterize the study and the manuscript as straightforward, with clear aims and an appropriate choice of methods to address them. The Methods are described in sufficient detail, and though the methodological approaches are not strictly speaking novel, they are entirely appropriate for the goals of the study.
The conclusions drawn are accurate. A few of my comments in the Discussion section merely include a couple minor suggestions on alternative explanations for the authors to consider, which would likely only require the addition of a couple sentences in the revision stage to address them. As noted above, I would strongly encourage the authors to add a table showing the REE concentrations from each specimen, so that all 'raw' data are clearly presented. The findings of the study bolster recent hypotheses about the impact of histology on trace element uptake and the relative severity of diagenetic alteration of bioapatitic tissues. Accordingly, as the authors conclude, the study's results provide case study examples of how paleontologists can identify (and thus constrain sampling to) the most unaltered regions of fossils for studies of molecular preservation and biogenic elemental and isotopic composition aimed at clarifying the paleobiology of the source taxon and/or the character of the depositional environment in which it was buried.
The authors manuscript is scientifically sound and interesting, and I have only minor comments aimed at improving the clarity of the findings and how they are described. My main recommendation is to include a new table showing the average REE and sum-REE concentrations, which could also be broken down by histological tissue type if the authors desire. Please see my uploaded PDF for minor suggestions on phrasing that can help make the text clearer in places, plus my few questions and detailed comments.
Paul Ullmann
This is an interesting paper describing the geochemistry of fossil vertebrate teeth from different taxa, ages, and localities. This study enhances our knowledge on how diagenesis affects fossil teeth, and will be useful for future studies that might be making paleobiological interpretations based on geochemical data.
My minor comments are related to the clarity of the writing.
Line 110, 115: do not use abbreviations to start sentences (Spell out EDS, LA-ICP-MS). The abbreviations are spelled out in the next paragraph (lines 118-122) but should be spelled out at first mention.
Line 120: remove ‘the’ before ‘several types’
Lines 348-350: I think a word is missing from this sentence.
Line 391: composed type-o
Lines 423-424: ‘The’ missing before Cerium and before Wonthaggi
Line 444: Add “is” before “in line”. Also, this whole paragraph should be modified, as it is confusing to refer to ‘our samples’ but then only be referring to the Australian samples. It feels like this paragraph was written before the Svalbard specimens were analysed. Is the presence of freshwater only relevant to the Australian samples?
Line 457: guide future analyses instead of guide ‘other analysis’.
I have no problems with the experimental design.
A few points need clarification:
Lines 294-304: I was confused here, as it is mentioned elsewhere in the paper that the lungfish does not have enamel, and there is no enamel indicated in the figures. What is being described in this paragraph?
Line 359: “F is present in the matrix”. Did you analyze the matrix that the specimens were found in? Those data should be included in the supplemental info, or cited if it was done previously.
All text and materials provided via this peer-review history page are made available under a Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.