Review Reports - A Skull of <i>Metriorhynchus palpebrosus</i> in the Kimmeridgian of Normandy (Northwest France) and the Status of the Genus Metriorhynchus: The End of the Mystery?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

thank you for submitting this manuscript on an interesting metriorhynchid skull from the Upper Jurassic of France, whose redescription is surely needed to better understand metriorhynchid interrelationships. However, I also have to say that I consider the manuscript in its current form to be seriously flawed and in my opinion not suitable for publication. For this reason, I recommend a rejection. Nevertheless, I took the time to comment on all aspects that need to be improved in my opinion. You will find detailed comments in the attached PDF. I will explain my main issues below.

At first, I want to emphasize that I have been not involved in the study of Young et al. (2021); although I authored papers that used versions of the same phylogenetic dataset. I am also aware that you follow the traditional, more inclusive view on which species should belong to Metriorhynchus and I want to highlight that this more or less philosophical disagreement is not the reason why I recommend a rejection.

Main issues
I. Misquoting of Young et al. (2021):

Your paper heavily focusses on the Metriorhynchus reassesment by Young et al. (2021). However, I found several instances, where you mispresent the contents of the paper and criticise claims they never made. This includes:

that they argued Chouquet cf. hastifer to be close to M. brevirostris (they actually highlight their clear differences);
that they do not cite your herein described skull (there actually is a discussion on its similarities to M. brevirostris);
that they found the rostral tip of the M. brevirostris holotype to be reconstructed (this actually applies to the M. palpebrosus holotype);
that they considered M. hastifer and M. palpebrosus to be conspecific (non such statement was made).

II. Surface-level critique of the found cladograms

You spend roughly one page criticising the phylogenetic analyses by Young et al. (2021) and in extension by other authors who used the same dataset. While you are certainly right that this is just "one tool among others" and that phylogenetically analyses need to be critically evaluated like all other methods, your discussion gives me the impression that you do not fully understand how a phylogenetic analysis works and that you did not do the due process to find out what is behind some of these "strange taxa" (i. e., reading the supplementary material of this or related works). Your decision to consider these analyses "irrelevant" is, hence, incomprehensible.

III. Missing morphological comparisons

The key messages of your paper are to me that the Pouchet skull is a specimen of M. palpebrosus and that M. hastifer as well as the Chouquet cf. hastifer specimen should be referred to M. brevirostris. However, as of now I find your given arguments not convincing. In the case of M. palpebrosus, you gave partly only vague statements on similarities or highlighted traits that might not be that informative on species level (tooth count) or might be distorted by taphonomy (the skull elevation in the holotype of M. palpebrosus) as well as that both specimens might not even be contemporaries (lower Kimmeridgian vs. lower Tithonian, both putative, though).
In terms of M. hastifer and the Chouquet skull, your asignment to M. brevirostris is mostly based on a single trait that is to my knowledge not restricted to Metriorhynchus sensu stricto. Also, you did apperantly not consider the discussion on the differences between M. brevirostris and the Chouquet skull as done by Young et al. (2021), including the unique tooth and alveolar morphology of the Chouquet skull and other specimens of the "E-clade" (see also Abel et al. 2020; Young et al. 2020). Lastly, this paper misses comparisons with species outside of Metriorhynchus sensu lato. Especially considering the statement by Young et al. (2021) that the occiput of the Pouchet skull shows traits so far only known from members of Rhacheosaurini.

While these issues, if viewed isolated, may not be reason enough to reject the manuscript, taken together I consider this beyond "major revisions" and encourage the authors to rework their study on this certainly relevant specimen.

Kind regards.

Comments for author File: Comments.pdf

Author Response

Main issues

Misquoting of Young et al. (2021):

Your paper heavily focusses on the Metriorhynchus reassesment by Young et al. (2021). However, I found several instances, where you mispresent the contents of the paper and criticise claims they never made. This includes:

>>>> answers in blue

that they argued Chouquet cf. hastifer to be close to M. brevirostris (they actually highlight their clear differences);

>>>>p546 left

« Lepage et al. (2008) provisionally referred the specimen to Metriorhynchus cf. hastifer, but the phylogenetic analysis of Abel et al. (2020) places this specimen in the unnamed geosaurine ‘E’-clade. Like other members of the ‘E’-clade »

with a bit after

« As such, based on comparative anatomy and the results of our phylogenetic analyses we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade »

E-Clade having for us no taxonomic validity, (variability inside a genus not well understood ?)

that they do not cite your herein described skull (there actually is a discussion on its similarities to M. brevirostris);

>>>p546 right

« The shape of the anterior (M1–M3) maxillary alveoli differ between the two specimens with the alveoli being more irregular in shape and more closely-packed in the Lepage et al. (2008) Me. cf. palpebrosus specimen. The variation in tooth count and alveolar shape/spacing could reflect ontogenetic, individual and/or sexual variation. Given the similarities between both specimens, we consider the specimen figured in Lepage et al. (2008: 137–139) to be better considered as Metriorhynchus cf. brevirostris. »

that they found the rostral tip of the M. brevirostris holotype to be reconstructed (this actually applies to the M. palpebrosus holotype);

>>>> ok, you are totally right i made this mistake and correct it

that they considered M. hastifer and M. palpebrosus to be conspecific (non such statement was made).

>>> sorry but when you say

« we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade (=M. cf. hastifer of Lepage 2008) «

« we consider the specimen (=M. palpebrosus) figured in Lepage et al. (2008: 137–139) to be better considered as Metriorhynchus cf. brevirostris. »

We could consider as conspecific, i will attenuate by « suggest » but nevertheless, this is strongly suggested, i correct by « Both specimens described in [1], M. cf. hastifer and M. palpebrosus skull were considered by Young et al [4] close to M. cf. brevirostris »

Surface-level critique of the found cladograms

>>> sorry but at the base when you have 15 taxa (/48 = 30%) not relevant because mixing subfamily to species, or even worse (like the callovian Dakosaur…In France, officially the scientific responsible of the french museum Paleospace to M. Young but no official answer …, i think that objectivly it has to be noticed. Other authors wanting to use theirs results have to be warmed of this paper has some weakness (like mine ), the perfect paper being rare

III. Missing morphological comparisons

The key messages of your paper are to me that the Pouchet skull is a specimen of M. palpebrosus and that M. hastifer as well as the Chouquet cf. hastifer specimen should be referred to M. brevirostris.

>>> not at all, only Chouquet cf. hastifer due to the special buccal apparatus

However, as of now I find your given arguments not convincing. In the case of M. palpebrosus, you gave partly only vague statements on similarities or highlighted traits that might not be that informative on species level (tooth count) or might be distorted by taphonomy (the skull elevation in the holotype of M. palpebrosus) as well as that both specimens might not even be contemporaries (lower Kimmeridgian vs. lower Tithonian, both putative, though).

In terms of M. hastifer and the Chouquet skull, your asignment to M. brevirostris is mostly based on a single trait that is to my knowledge not restricted to Metriorhynchus sensu stricto

>>> as already told in the paper the type of M. brevirostris is only a « classical metriorhynchid snout but it as this special character, noticed by Lennier 1886 , the double « gutters » only seen on the type of M. hastifer (figured but disappeared), the type of M. brevirostris and the chouquet cf.hastifer

. Also, you did apperantly not consider the discussion on the differences between M. brevirostris and the Chouquet skull as done by Young et al. (2021), including the unique tooth and alveolar morphology of the Chouquet skull and other specimens of the "E-clade" (see also Abel et al. 2020; Young et al. 2020).

>>> E-clade is what not even a sub family, this is not a valid taxonomic rank, you imagine a taxonomy with such nomenclature ?

. As you see on our skull alveolar morphology can’t be used alone as a valid taxonomic value, the authors even miss that on our skull left half of the tooth row was missing and missed the only teeth known (abnormal but present) of the M. palpebrosus

Lastly, this paper misses comparisons with species outside of Metriorhynchus sensu lato. Especially considering the statement by Young et al. (2021) that the occiput of the Pouchet skull shows traits so far only known from members of Rhacheosaurini.

>>> frankly speaking, having seen this skull at first hand, this skull is too crushed in this area to have relevant informations

While these issues, if viewed isolated, may not be reason enough to reject the manuscript, taken together I consider this beyond "major revisions" and encourage the authors to rework their study on this certainly relevant specimen.

Kind regards.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor and authors,

I congratulate the authors for such interesting contribution. However, I have some main comments that I think should be addressed. At first, you should re-phrase several sentences that are very long and usually do not go direct to the point. On the other side, the illustrations of the entire skull should be greatly improved.

In any case, the contribution is valuable, and I think Tat it should be published after some changes.

I am attaching a PDF including some of my observations

Comments for author File: Comments.pdf

Author Response

comments are put in the file but all were taken in account

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This article describes a skull attributed to the species Metriorhynchus palpebrosus, which was discovered in Normandy in the last century. It discusses a re-evaluation of the Metriorhynchus genus, focusing particularly on M. brevirostris, M. hastifer and M. palpebrosus. The manuscript proposes that M. brevirostris should be considered a synonym of M. hastifer.

Abstract.

The abstract is very brief. I suggest expanding it by specifying the research problem and the methodology used to arrive at the results. You should also discuss the results and draw conclusions.
The keywords should not be the same as those in the title.

Introduction

The introduction is too long and confusing, and it does not clearly explain the research problem. It needs to be organised and restructured, with the primarily methodological aspects separated out.
The captions of the images should provide better descriptions, and a glossary of abbreviations should be included. Rather than including them in the introduction, I suggest carefully considering whether they will be part of the methods or results section.
It is essential that figures are labelled to indicate the structures described in the text, and that a scale is included to show the size of the structures.
I suggest restructuring the introduction so that it does not begin by assuming prior knowledge of which skull will be discussed. Instead, it should start with a general explanation of what will be analysed, where it came from, why it needs to be analysed and what insights will be gained. The research objective should be mentioned, and if possible, a hypothesis to be tested should be proposed.

Methods

Although there is no methods section, I suggest adding one. This would improve the organisation of the manuscript, making it easier to read and ensuring that the research problem is adhered to. This section should detail which pieces were analysed, where they came from, how access was obtained for analysis, what type of analysis was performed and any other necessary information.

Results

The results section is also missing and must be included. This would bring order to the manuscript and enable the synthesis and structuring of the descriptive information. Including a table would help to consolidate and summarise the recorded and analysed data.
In section 2.2: Cranial Openings (Figures 2, 3 and 4) and 2.4, Cranial Bones (Figures 1 and 4), figures are mentioned that are not shown in the text, such as Figure 8 and Figure 48.
Figures should be included in these sections; however, care must be taken with the descriptions. For example, Figures 1 and 2 refer to M. palpebrosus in their titles, but are mentioned in reference to M. brevirostris.

Discussion

In point 9 of the discussion, 'our specimen' is mentioned, but it is unclear which specimen is being referred to throughout the text. It is complained that it is not cited in Young's work, but how could it be cited? Is there any prior reference to this manuscript? Or are they referring to their museum consultation? Please specify.
- 3.1. The genus Metriorhynchus. Figure 8 is not included in the manuscript. Figure 5 corresponds to a honeycomb diagram, not a cladogram for phylogenetic analysis, and is not included in the manuscript.
The discussion is framed as a critique of the work of Young et al., but does not mention how this study could complement the aforementioned cladogram or what the authors of this manuscript could include to improve it with the necessary modifications.
It is mentioned that: 'The cladistic analysis performed with software, which evolves through various versions and updates like all software, should be considered only one more tool and not the definitive solution. It should be integrated with other tools, such as statistics.' However, neither of the two analysis tools is included in the present manuscript: neither the phylogenetic analysis with software nor the statistical analysis that compares the different bone characteristics mentioned throughout the manuscript.
I suggest not including the entire explanatory paragraph in French without a translation or detailed explanation, as it doesn't contribute much to the discussion.
At the end of section 2, it states: 'To distinguish these species, and given that the genus Metriorhynchus is no longer monospecific, the following amended diagnosis is proposed, based on the combined studies of [4; 10; 19].' This should be the outcome, with a prior methodology specified to outline the basis of the analysis.

Conclusions

'It provides a better understanding of Metriorhynchus brevirostris, the type species of the genus Metriorhynchus. Previously, this species was only known from an isolated snout, but now we have a more complete picture based on other known specimens.' Which specimens? Specify the collections involved and their history as part of the methodology.
A direct consequence of a better definition of the type species of Metriorhynchus is that the coexisting species M. palpebrosus is also better defined. What do you mean by this? Please specify.

Comments for author File: Comments.pdf

Author Response

Many thanks for you detailed report, i hope you will find all your answers, in the corrected version

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

thank you for your response. Unfortunately, the system used by MDPI does not show the formatting in your response and which sentences you highlighted in blue. I hope the formatting in my reply is visible and it doesn't get too chaotic.

- Regarding that Young et al. (2021) claimed the Chouquet cf. hastifer specimen being close to M. brevirostris. I highlighted that they did not do this. Your response is the following quote:

with a bit after

« As such, based on comparative anatomy and the results of our phylogenetic analyses we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade »

I don't understand why you leave out the section that discusses the differences, including shape of the anterior-mid maxillary alveoli, shape and size of the premaxillary alveoli, size of the interalveolar spaces, and how this is most similar to Geosaurini. Not to mention that your quoted sentence literally says a relationship can be precluded. Whether the "E-clade" has an official name or not does not negate the morphology of the specimens within it.

- Regarding your claim that they do not cite the Pouchet skull, you cite the section where they do (Metriorhynchus cf. brevirostris is the Pouchet skull), proving my point.

- Regarding your claim that Young et al. (2021) considered/suggested M. hastifer and M. palpebrosus to be conspecific, you now write the following:

« we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade (=M. cf. hastifer of Lepage 2008) «

« we consider the specimen (=M. palpebrosus) figured in Lepage et al. (2008: 137–139) to be better considered as Metriorhynchus cf. brevirostris. »

No, there seems to be a misunderstanding on your part. Like written above, they consider "M. cf. hastifer" (the Chouquet skull) to be a geosaurin within the "E-clade" cleary different from M. brevirostris and they say that Lepage et al's "M. cf. palpebrosus" (so, your redescribed Pouchet skull) is better referred to as "M. cf. brevirostris" for now due to its similarities to the M. brevirostris holotype. They don't make any statements on the actual M. hastifer and M. palpebrosus holotypes apart from what is written in Table. 5.

- Regarding what I called surface-level critique on the phylogenetic analyses performed by Young et al. (2021) or in similar papers. You reply by the following:

>>> sorry but at the base when you have 15 taxa (/48 = 30%) not relevant because mixing subfamily to species, or even worse (like the callovian Dakosaur…In France, officially the scientific responsible of the french museum Paleospace to M. Young but no official answer …, i think that objectivly it has to be noticed. Other authors wanting to use theirs results have to be warmed of this paper has some weakness (like mine ), the perfect paper being rare

I wrote several, in parts lengthy comments regarding this in your original manuscript. It seems to me you do not understand what an operational taxonomic unit is and that you are putting too much emphasis on what are just unofficial/preliminary OTU names. But there are actual (sometimes nicely preserved) specimens behind those preliminary OTU names. I don't understand what you want to say with the other part of your reply.

- Regarding the key messages of your paper, I wrote that I understood you as claiming the M. hastifer holotype and the Chouquet skull being referrable to M. brevirostris. Now you reply the following:
">>> not at all, only Chouquet cf. hastifer due to the special buccal apparatus"

But in your original draft you wrote in your abstract "A link is made to synonymize M. brevirostris with M. hastifer, this latter be-coming a junior synonym". As well as later on p. 12 "Now, re-examining the photos of the holotype of M. brevirostris, it appears that we can see the same two longitudinal ridges as found in M. hastifer and described successively by Eudes-Deslongchamps and Lennier; this indicates that the rostrum of M. brevirostris could belong to the same species as M. hastifer and thus brevirostris = hastifer."
Those are pretty clear statements to me regarding them being synonymous? You even say so in your next reply.

- Regarding the suggested apomorphy uniting M. brevirostris with M. hastifer and the Chouquet skull, which I do not found convincing, you reply:
">>> as already told in the paper the type of M. brevirostris is only a « classical metriorhynchid snout but it as this special character, noticed by Lennier 1886 , the double « gutters » only seen on the type of M. hastifer (figured but disappeared), the type of M. brevirostris and the chouquet cf.hastifer"

Like indicated before, it might be I misunderstand your character. But if I understand it correctly, I would claim it's also present in other metriorhynchids, for example superciliosus. However, as far as I can see, you don't make a statement regarding my comment.

- Regarding my critique that you do not consider the discussions of Abel et al. (2020) and Young et al. (2021) on the unique alveolar and tooth morphology of the "E-clade", including the Chouquet specimen. You reply:
">>> E-clade is what not even a sub family, this is not a valid taxonomic rank, you imagine a taxonomy with such nomenclature ?

For what it is worth, the "E-clade" has been repeatedly found to be within the subfamily Geosaurinae. Nobody treats it as a taxonomic rank.

Also, nobody claimed that alveolar morphology is of taxonomic value on its own. I criticized that you do not discuss traits of those specimens that are to my knowledge unique among Metriorhynchidae (apart from the fact, that you use a single trait yourself to unite M. hastifer and the Chouquet specimen with M. brevirostris).

- Regarding my request to compare the Pouchet skull also with specimens outside of Metriorhynchus sensu stricto, for example with rhacheosaurins as Young et al. (2021) found similarities in the occiput of the Pouchet skull with this Tribus, you write:
">>> frankly speaking, having seen this skull at first hand, this skull is too crushed in this area to have relevant informations"

This is a legit opinion, of course, but if you disagree with the respective authors, you should also include it in your manuscript, especially considering there aren't that much papers that already discussed the affinities of the Pouchet skull. Even though, you do indeed compare the occiput of the Pouchet skull to "M." brachyrhynchus. So, according to you, it is informative to some degree.
You don't make a statement, why you don't compare it to other metriorhynchids outside of Metriorhynchus. Also, you did not reply to or integrated my objection that the M. palpebrosus holotype might be actually Tithonian in age (see Cox 2001), or that its postorbital elevation might be taphonomic. Both arguments that should be considered before asinging the Pouchet skull to this species.

Kind regards

Author Response

Answers to rev1 round 2

Hi, my answers are underlined (just to be readable, sorry…)

>>> a great thanks for your time and your very interesting and rich comments

thank you for your response. Unfortunately, the system used by MDPI does not show the formatting in your response and which sentences you highlighted in blue. I hope the formatting in my reply is visible and it doesn't get too chaotic.

- Regarding that Young et al. (2021) claimed the Chouquet cf. hastifer specimen being close to M. brevirostris. I highlighted that they did not do this. Your response is the following quote:

with a bit after

« As such, based on comparative anatomy and the results of our phylogenetic analyses we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade »

>>>>>> Frankly speaking , if the authors, having in first hands the material are not able to appreciate enough the variation of their specimen to distinguish any generic or specific taxon from the others, where is the limit with the variation of other better known genus? You are agree that for you they are Geosaurinae indet, so only sure of the family. For me, at least such comparisons could be relevant if you are sure to compare at least with a well identified genus and this is not the case at all, so for me, this is not relevant specimens awaiting better specimens or revision to beeter define such clade

- Regarding your claim that they do not cite the Pouchet skull, you cite the section where they do (Metriorhynchus cf. brevirostris is the Pouchet skull), proving my point.

>>> on their cladogram only, I modify my text on this way, you are right my sentence is not really clear

- Regarding your claim that Young et al. (2021) considered/suggested M. hastifer and M. palpebrosus to be conspecific, you now write the following:

« we can preclude a relationship between Metriorhynchus brevirostris and the enigmatic ‘E’-clade (=M. cf. hastifer of Lepage 2008) «

« we consider the specimen (=M. palpebrosus) figured in Lepage et al. (2008: 137–139) to be better considered as Metriorhynchus cf. brevirostris. »

No, there seems to be a misunderstanding on your part. Like written above, they consider "M. cf. hastifer" (the Chouquet skull) to be a geosaurin within the "E-clade" cleary different from M. brevirostris and they say that Lepage et al's "M. cf. palpebrosus" (so, your redescribed Pouchet skull) is better referred to as "M. cf. brevirostris" for now due to its similarities to the M. brevirostris holotype. They don't make any statements on the actual M. hastifer and M. palpebrosus holotypes apart from what is written in Table. 5.
>>>> right, I delete the ultimate sentence it is a clumsiness from my side
- Regarding what I called surface-level critique on the phylogenetic analyses performed by Young et al. (2021) or in similar papers. You reply by the following:

>>> sorry but at the base when you have 15 taxa (/48 = 30%) not relevant because mixing subfamily to species, or even worse (like the callovian Dakosaur…In France, officially the scientific responsible of the french museum Paleospace to M. Young but no official answer …, i think that objectivly it has to be noticed. Other authors wanting to use theirs results have to be warmed of this paper has some weakness (like mine ), the perfect paper being rare

I wrote several, in parts lengthy comments regarding this in your original manuscript. It seems to me you do not understand what an operational taxonomic unit is and that you are putting too much emphasis on what are just unofficial/preliminary OTU names. But there are actual (sometimes nicely preserved) specimens behind those preliminary OTU names. I don't understand what you want to say with the other part of your reply.
>>> Sorry, it was about Viller Dakosaur, OTU or not, this term is irrelevant from the genus name and/or for location
- Regarding the key messages of your paper, I wrote that I understood you as claiming the M. hastifer holotype and the Chouquet skull being referrable to M. brevirostris. Now you reply the following:
">>> not at all, only Chouquet cf. hastifer due to the special buccal apparatus"

But in your original draft you wrote in your abstract "A link is made to synonymize M. brevirostris with M. hastifer, this latter be-coming a junior synonym". As well as later on p. 12 "Now, re-examining the photos of the holotype of M. brevirostris, it appears that we can see the same two longitudinal ridges as found in M. hastifer and described successively by Eudes-Deslongchamps and Lennier; this indicates that the rostrum of M. brevirostris could belong to the same species as M. hastifer and thus brevirostris = hastifer."
Those are pretty clear statements to me regarding them being synonymous? You even say so in your next reply.
>>> so I think we are agree? I don’t understand
- Regarding the suggested apomorphy uniting M. brevirostris with M. hastifer and the Chouquet skull, which I do not found convincing, you reply:
">>> as already told in the paper the type of M. brevirostris is only a « classical metriorhynchid snout but it as this special character, noticed by Lennier 1886 , the double « gutters » only seen on the type of M. hastifer (figured but disappeared), the type of M. brevirostris and the chouquet cf.hastifer"

Like indicated before, it might be I misunderstand your character. But if I understand it correctly, I would claim it's also present in other metriorhynchids, for example superciliosus. However, as far as I can see, you don't make a statement regarding my comment.
>>>> the snout is really a classical/typical Metriorhynchid skull but it has additionnally this really specific character of the double “gutters”, seen in the lennier 1884 description, the snout type of M. Brevirostris and the M. cf. hastifer of Chouquet. (When I thought to have found this character, I was proud of my discovery until I read Lennier, the official first people to have seen it )…

- Regarding my critique that you do not consider the discussions of Abel et al. (2020) and Young et al. (2021) on the unique alveolar and tooth morphology of the "E-clade", including the Chouquet specimen. You reply:
">>> E-clade is what not even a sub family, this is not a valid taxonomic rank, you imagine a taxonomy with such nomenclature ?

>>> for me, the fact that because any specific rank has been given to this E-clade, may be inside we have various taxon so we are mixing many things. The name itself indicateds that authors are not really sure of themselves for me. On my famous trait, it has been noticed among nearly thousand of skulls known only 3 times and surely on Metriorhynchus genus even including ante WWII destroyed beautiful specimens, it has to be underlined (and showing this is not pathologic). From Chouquet specimen, agree that until a serious study (and in public institute) we will be sure. I modified my text in this way

- Regarding my request to compare the Pouchet skull also with specimens outside of Metriorhynchus sensu stricto, for example with rhacheosaurins as Young et al. (2021) found similarities in the occiput of the Pouchet skull with this Tribus, you write:
">>> frankly speaking, having seen this skull at first hand, this skull is too crushed in this area to have relevant informations"

This is a legit opinion, of course, but if you disagree with the respective authors, you should also include it in your manuscript, especially considering there aren't that much papers that already discussed the affinities of the Pouchet skull. Even though, you do indeed compare the occiput of the Pouchet skull to "M." brachyrhynchus. So, according to you, it is informative to some degree.

>>> misunderstanding of my side, I think you were speaking of M. hastifer of Chouquet collection” where the occiput is really crushed.

Concerning the occiput of my specimen, the state of preservation and the age of the specimen do not allow to clearly see various occipital sutures. And sure, it has some similarities with this Callovian species. You point rightly the importance of the definition of the Metriorhynchus genus itself, and I hope this paper being sufficiently informative to better understood this gordian node as rightly named by Mr Young. Because if you better understand this genus, you better understand the rest of the family. Now I hope with this better definition, we could better after apprehend the upper taxon like Raechosaurin, but for me it was not the target. The paper of Young et al. is excellent in the way that telling all the family is based on a incomplete rostrum of the genus Metriorhynchus , the basement of the house Metriorhynchidae. With a better basement (I hope) we could reexamine after all the upper taxon

You don't make a statement, why you don't compare it to other metriorhynchids outside of Metriorhynchus (1) . Also, you did not reply to or integrated my objection that the M. palpebrosus holotype might be actually Tithonian (2) in age (see Cox 2001), or that its postorbital elevation might be taphonomic (3). Both arguments that should be considered before asinging the Pouchet skull to this species.

>>> many points to answer

Clearly this specimen for all the authors is a Metriorhynchus, whatever the definition given to it From Buffetaut, Vignaud me or Young and the sentence l.390 for me is sufficient, so I prefer to concentrate the paper around the question “what is a Metriorhynchus?”

(2) The age of the specimen : the big pb of this historic skull, never really located in the first papers, only mentioned compared to the levels of M. palpebrosus but really when I saw the original cast of M. palpebrosus I am sure of the diagnosis. I will point this geologic weakness l. 442

(3) clearly not all, this is one exceptional characteristics of the Le havre and Villers skulls, they have nearly no distorsion l.171

Kind regards

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors addressed most of my comments on a previous version of the MS

Author Response

Hi, as all my answers seems to have satisfied my reviewer

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript describes a skull that has been assigned to the species Metriorhynchus palpebrosus, which was discovered in the Late Jurassic period in Normandy. It provides a re-evaluation of the genus Metriorhynchus, focusing particularly on M. brevirostris, M. hastifer and M. palpebrosus, which were found in France and England. The article proposes synonymising M. brevirostris and M. hastifer based on a morphological autapomorphic character. This interpretation is intended to improve our understanding of this genus, and of European Late Jurassic species more broadly.

This second submission improves upon the original manuscript, presenting valuable information. However, I believe it requires some formatting adjustments to improve readability. While I understand that the authors may not wish to include the methods and results sections, the structure of the manuscript still needs to be modified. Specifically, I suggest adding two sections: Geological Setting and Phylogenetic Analysis. This would not necessarily imply including more text, but rather analysing the existing text and organising it into sections so that it can be explained more clearly.

Comments for author File: Comments.pdf

Author Response

Concerning analysis :

I have modified some point on my discussion, I hope you will appreciate. I insist on the fact ,on my famous trait, the double gutters, it has been noticed among nearly thousand of skulls known only 3 times and surely on Metriorhynchus genus even including ante WWII destroyed beautiful specimens, it has to be underlined (and showing this is not pathologic). From Chouquet specimen, agree that until a serious study (and in public institute) we will be sure. I modified my text in this way

Author Response File: Author Response.docx

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript has been sufficiently improved for publication. The revisions to the discussion and conclusions are clear. In terms of editing, the double title in Figure 5 can be avoided by removing the top title, and a legend for the 'Y' axis should be added.