Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: THE BODY PLAN OF HALSZKARAPTOR ESCUILLIEI (DINOSAURIA, THEROPODA) IS NOT A TRANSITIONAL FORM ALONG THE EVOLUTION OF DROMAEOSAURID HYPERCARNIVORY
Review round: 1
Reviewer: 2

Output:
Basic reporting: See below. Although I commend the author for their speed in writing this response, I have many concerns about how this paper argues for a semiaquatic ecology in Halszkaraptor. The paper repeats many problems with the original paper, including improper comparisons of the anatomy of Halszkaraptor with aquatic and semiaquatic taxa that employ disparate locomotory modes and ecologies and are in fact very different in the relevant features of their anatomy. This paper also presents the arguments published in Cau et al. (2017) in a way that misleadingly supports the argument made here. I also have concerns about specific details of the arguments presented that the author considers factual but are actually not correct. These include statements made on the anatomy of the dentaries of dromaeosaurids, the forelimb of Halszkaraptor, and other features.
Experimental design: See below. Although I commend the author for performing new morphometric, phylogenetic, and optimization analyses, I have a number of major concerns about the over-interpretation of these results to fit the argument made in the paper. The author over-interprets the results of the optimization analysis, suggests the phylogenetic analysis conducted in the rebuttal was highly flawed even though it essentially matched the topology found in Cau et al. (2017) with the exception of finding a sister-taxon relationship between Unenlagiinae and Halszkaraptorinae (also found in the analysis here and in other analyses of the Cau et al. dataset). Many of the new morphometric analyses conducted are not relevant to the features the author discusses, such as the flattening of the ulna.
Validity of the findings: See below. I thank the author for clarifying a number of points in the original paper, but I also feel that this paper backtracks on the arguments made in Cau et al. (2017) in order to refute the rebuttal's arguments. I have concerns about the morphometric analyses, and believe the conclusions stem from important misinterpretations of the morphology of relevant taxa. Furthermore, the results of this study in some cases seem to advance arguments made in the rebuttal. Despite this, the author frames that study as highly flawed.
Additional comments: Peer Review of “The body plan of Halszkaraptor escuilliei (Dinosauria,
Theropoda) is not a transitional form along the evolution of
dromaeosaurid hypercarnivory”

Chase Brownstein

Dear Dr. Knoll,

I submit to you my review of Andrea Cau’s rebuttal of my recent rebuttal of a 2017 paper authored by him and colleagues in Nature. I commend the author for their quick, rigorous work, which is impressive. As laid out in my original paper, I have disagreements about what Halszkaraptor represents, but I very much agree that scientific discussion on this taxon is warranted and I appreciate and thank the author for putting together this paper responding to mine.

I am concerned with statements made in this rebuttal that repeat many of the errors made in the original paper with regards to the comparative anatomy work, the morphometric analyses conducted, and the phylogenetic analyses performed. I am also concerned that this paper backtracks on several arguments made in Cau et al. (2017) in order to characterize the rebuttal paper as inadequately responding to the original work's arguments. Finally, the many minor critiques presented here of the rebuttal paper neither serve to strengthen the argument about the ecology of Halszkaraptor (the goal of this paper) nor are in fact correct/supported by the anatomy of the relevant taxa.

Principally, this paper misconstrues the intent of the rebuttal. The transitional hypothesis was given as an alternative to the semiaquatic ecology hypothesis, which the rebuttal aimed to show was poorly supported. The way this paper is construed suggests the intent here is to suggest that if the alternative hypothesis (transitional form) does not hold, the semiaquatic hypothesis must. This is an incorrect assumption, as the null hypothesis in this case is that Halszkaraptor did not possess an aberrant ecology. Furthermore, this paper seems to confirm several points made in the rebuttal against interpreting the anatomy of Halszkaraptor to represent a semiaquatic specialization.

Given the issues I note, I think this paper in large part consists of critiques that do not serve to effectively support the original paper’s argument or show major flaws in the rebuttal. I do think there are plenty of important points made in this paper that would serve to strengthen the argument that Halszkaraptor is not transitional in some of the ways mentioned in the rebuttal. Note that this doesn't support a semiaquatic ecology in Halszkaraptor, which the rebuttal paper aimed to show was poorly supported.

Focusing on the following portions of the paper I think would provide an important response argument and contribution:

—Keeping the discussion of premaxillary expansion and foramina count increase.
—Conducting new morphometric analyses on the ulna of Halszkaraptor in line with the comments given above.
—Discussing the issue of the morphologies of the supratrochanteric process and cervical vertebrae
—Presenting the phylogenetic analysis and discussing why the rebuttal argument’s phylogeny is incorrect in important ways.

 In the paragraphs below, I detail my concerns with particular sections of this paper.

Lines 71—93: Here, the author suggests that my characterization of the comparability of the rostral margin of the skull of Halszkaraptor with other maniraptoran theropods. Firstly, the paper presents my argument as one that is objectively inaccurate in the face of the literature. As the author discusses in lines 77—93, this is actually a question of anatomical homology, and so I think this section should be moved to the later general discussion in the paper. This section is predicted on the idea that anterior elongation and lateral expansion of the premaxillae is not homologous with the simple lateral expansion of the premaxillae. This is all well and good, but the point made in the original paper was that the expansion of the premaxillae observed in Halszkaraptor was unique to that taxon among Mesozoic paravians and most other coelurosaurs. The author seems to agree that the only major difference concerns the relative position of the internarial bar base along the anteroposterior margin of the premaxilla, because other coelurosaurs like therizinosauroids and ornithomimosaurs have laterally expanded premaxillae. That this feature is only more posteriorly placed than in other maniraptorans is a very tenuous feature on which to base comparisons with piscavorous archosaurs like crocodylians and spinosaurs. This is because spinosaurines like Spinosaurus and Irritator possess far more posteriorly retracted nares than Halszkaraptor (e.g., Ibrahim et al., 2014) and the rostra of crocodylians are far more flattened than theropods such that the nares/naris are/is strongly oriented dorsally and usually not visible in lateral view. Where the point of contention therefore lies is whether the premaxillary anatomy of Halszkaraptor is comparable to baryonychine spinosaurids like Baryonyx, which are known to have eaten fish (as well as a variety of terrestrial animals; Buffetaut et al., 2004). Using this feature to support the hypothesis that Halszkaraptor was a piscavore without considering these details is therefore premature, and the premaxillary margin of Halszkaraptor clearly shares more in common with the average maniraptoran than with clearly aquatic taxa like modern alligators, where the naris/nares are entirely oriented dorsally, or with spinosaurines, which show a variety of puzzling adaptations in their skulls and bones that may provide more evidence for piscivory or specialization for hunting aquatic prey. Although one might bring up the existence of putative ‘webbed’ baryonychine tracks (Theroplantigrada), the assignment of these tracks to baryonychines and the presence of authentic webbing on them has been characterized as dubious in the literature (Conti et al., 2005). Resultantly, there is little direct evidence to suggest baryonychines were heavily adapted for a semiaquatic lifestyle in the way Halszkaraptor was posited to be (e.g., as a forelimb-propelled or undulating swimming semiaquatic piscivore), and the two lineages differ in several key aspects of the features Cau et al. (2017) used to compare them.

95—105: This discussion concerns the author’s assertion that I misinterpreted the phrasing in Cau et al. While I agree there is a clarification to be made that the premaxillary morphology suggests that the naris is retracted, my point was to say that the naris might not extend so far posteriorly so that it would be allied with the condition in spinosaurids, to which Cau et al. (2017) originally compared Halszkaraptor. In fact, the skull reconstruction published in Cau et al. (2017) reconstructs the narial margin of the nares as being greater in anteroposterior length than the narial margin of the premaxillae. As I noted in my paper, this is not the condition seen in any dromaeosaurid for which the nasals and premaxillae are known. This statement is based on firsthand observation of the skulls/skull material casts of a variety of dromaeosaurids, including Bambiraptor, Velociraptor, Deinonychus, Dromaeosaurus, Tsaagan, etc.
With a quick look at the skulls of Velociraptor, Microraptor, or Deinonychus, this pattern becomes clear. The narial margin of the nasals is about the same length or far shorter than the margin in the premaxillae. If Cau et al. (2017) were to sufficiently compare this feature to the construction seen in baryonychine spinosaurids, they would have to argue the nares stretched far posteriorly, as is the case for Baryonyx and Suchomimus (Charig and Milner, 1997; Sereno et al., 1998). The nares of these spinosaurids are massive and stretch up to more than a fifth of the total length of their skulls. This is not the case in Halszkaraptor as the figures in this paper and in Cau et al. (2017) show. Therefore, the critique of the rebuttal paper’s argument presented here is misconstrued, because the naris would have to be elongate in addition to posteriorly located on the premaxilla to show a strongly retracted condition comparable to baryonychine spinosaurs.

106—120: As with many other statements in this rebuttal, this paragraph suggests that I misinterpreted the argument of Cau et al. (2017) that the bizarre rostral adaptations of Halszkaraptor are linked with a semiaquatic life or a life at least spent foraging for aquatic prey. See my other comments for why I feel this argument misconstrues what was written in the original study.

123—154: This section concerns the relative amount of neurovascular foramina along the premaxillae of Halszkaraptor relative to other taxa, and provides an important additional set of comparisons supporting the number of medially- and dorsally-placed foramina on the premaxillae of Halszkaraptor as a potential autapomorphy of this taxon. However, the author admits that other maniraptorans also do possess foramina on the dorsal surface of their premaxillae, something that was not said in the original paper. Given the scarcity of well-preserved premaxillae for basal members of many maniraptoran and coelurosaurian clades, the notion that the condition in Halszkaraptor of these foramina being more numerous is extremely unlike other maniraptorans seems a premature one to make. Although I agree that this feature seems potentially distinctive, its contribution to the ecological arguments given by Cau et al. should not be overstated. As the author notes and as is visible in theropods, superficial neurovasculature can change noticeably from taxon to taxon. Although this feature might be allied with that seen in crocodylians, there is not any strong evidence for that interpretation being better than the null hypotheses that this feature (1) is not highly distinctive given the poor basal paravian/maniraptoran record or (2) is unrelated to a piscivorous ecology.

156—190: The author here argues that I misrepresented the affinity of the tooth replacement condition in Halszkaraptor to those of other maniraptorans. From the acknowledgements, it is clear the author consulted with one of the authors of the paper I cited the most in my discussion of this feature. I very much appreciate that the author did this. Making sure to clarify homology is important but often overlooked work, so good on the author for doing so! However, I do not think the author’s discussion of this issue is exactly correct. As the author notes, there is a difference between the replacement pattern observed for the premaxillary teeth with the pattern observed for maxillary crowns in Halszkaraptor. Zanno and Makovicky (2011) discussed a generally low replacement rate as potentially related to herbivory in maniraptorans. Cau et al. (2017) state that the “protracted replacement in [the] anterior dentition” of Halszkaraptor was indicative of a semiaquatic ecology. This indicates that the replacement of the anterior dentition took a longer time than that of the maxillary dentition, which I allied with the delayed replacement seen in the teeth of maniraptorans in my paper. My argument was simply to say that the difference in maxillary/premaxillary replacement in Halszkaraptor might reflect that one of these changes in replacement was occurring.

192—200: The texts original 2017 paper clearly shows that comparisons with long-necked marine birds were made deliberately. The paper did not compare the neck of Halszkaraptor to giraffes, for example, because the point was to compare the cervicals of Halszkaraptor to semiaquatic and/or piscivorous species that also had elongate necks. The following quotations from the 2017 paper support this being the original argument:

“Compared to body size, the neck is elongate and forms 50% of the snout–sacrum length; this is the highest value found among Mesozoic paravians ….The first five neural arches are also
unique among theropods in their lack of inter-postzygapophyseal spaces: instead, each pair of postzygapophyses forms a single planar surface that faces ventrally and has a convex posterior margin. This morphology is also seen in some long-necked chelonians and a few birds (for example, Cygnus, Fig. 3h–j).” Cygnus is a long-necked aquatic bird.

Figure 3 caption in Cau et al. (2017) states: “Dorsal view of anterior cervical vertebrae of Cygnus (h), the fresh-water chelonian Araripemys (i) and Halszkaraptor (j). These vertebrae share a combination of features: (1) elongate neural arches with reduced ridge-like neural spines; (2) merged postzygapophyses that form a lobate process; (3) ribs fused to vertebra; and (4) horizontally oriented zygapophyseal facets.”

“Neck elongation is widespread among sauropsids that use an ambush mode of predation in water, and the cervical morphology of Halszkaraptor (unique among non-avian theropods) is exclusively shared with semiaquatic lineages such as araripemydid turtles and some long-necked anatids (Fig. 3g–i).”

The intention of the comparisons made was clearly to compare Halszkaraptor with long-necked semiaquatic birds and other long-necked semiaquatic lineages, including some turtles and plesiosaurs. It is therefore a mischaracterization of the original study in suggesting these discussions did not take place, and one that benefits the author’s stance that the rebuttal manuscript was picking at straws, so to speak.

211—217: The citation refers to what the sentence says about Halszkaraptor being the first aquatic non-avian maniraptoran, which is what the Cau et al. paper claimed. This paragraph is just a minor critique of where the reference was placed. Furthermore, the phylogenetic topology of Cau et al. (2017), when considered alongside their semiaquatic hypothesis for halszkaraptorines, might be taken to indicated a semiaquatic ecology was developed early in dromaeosaurid development. In any case, this issue does not impact the larger arguments made in the rebuttal regarding the semiaquatic ecology proposed by Cau et al. 2017.

219—229: The author suggests I mischaracterized the Djadokhta Formation paleoenvironment and simultaneously agrees that semiaquatic species are rare. The author suggests that the presence of the crocodyliform Shamosuchus in the same ecosystem indicates a fauna adapted for an aquatic lifestyle, drawing anatomical similarities between Shamosuchus and Halszkaraptor in regarding rostral morphology. See above for my comments on the non-homoplastic nature of the snouts of crocodylians and Halszkaraptor. Overall, the aridity of the paleoenvironment would have made aquatic ecosystems rare. Given that the original description suggested Halszkaraptor was pretty strongly adapted to an aquatic environment (e.g., had a modified snout and neck for catching aquatic prey and a modified forelimb and body for swimming), this line of argument still stands strong.

231—256: The author suggests I misreported the anatomy of the distal dromaeosaurid dentary, and that dromaeosaurids did not possess chins. As I have personally examined the type specimens of a number of dromaeosaurids in institutions like the American Museum of Natural History and Yale Peabody Museum, I am sure that my identification of this feature is correct. Other authors, including Evans et al. (2013) and Xing et al. (2013), identify this feature in dromaeosaurids like Microraptor, Velociraptor, and Acheroraptor. Simply put, this paragraph presents false information. The “straightened” morphology of the dentary of dromaeosaurids refers to the fact that these animals lack dentaries that thin anteriorly to form a triangular outline, which is seen in troodontids. In Figure 3 of the original study, Cau et al. (2017) point out that the ventral margin of the dentary of Halszkaraptor is distally confluent with the rest of itself. Since the rest of the dentary clearly narrows slightly, this produces a small but noticeable rounded dentary end. Therefore, the author’s conclusion that I misinterpreted the anatomy of dromaeosaurids is unsubstantiated.

258—263: The term ‘ziphodont’ has been used in the literature dealing with theropods to both refer to serrated and unserrated labiolingually compressed, recurved teeth with distinct carinae. Hendrickx et al. (2015) characterize ziphodonty in theropod dinosaurs to refer to “strongly labiolingually narrows crown[s] with a distal curvature, typically serrated carinae, and no constriction at the cervix,” and note that “if the large majority of ziphodont theropods show serrated teeth, some of them, such as Buitreraptor and Compsognathus, whose teeth do not always bear denticles, are still considered to have a ziphodont dentition.” Halszkaraptor clearly shows the unserrated condition, and so “unserrated ziphodont teeth” is a valid description. Critiquing my paper for using this term the way it was used is also irrelevant to the argument the author makes. The important result in the original paper was that the general morphology of the dentition of Halszkaraptor was communicated. This and other minor points of contention raised in this paper do not respond to the rebuttal paper’s arguments.

272—288: The skeletal reconstruction of Halszkaraptor given clearly shows that the original hypothesis for the caudal series of this taxon was that it was shorter relative to the body of H. escuilliei than the caudal series of some other dromaeosaurids (e.g., Velociraptor). The author seems to agree with what I said in my paper that the caudal series of Halszkaraptor is similar to those of basal members of other paravian lineages, and so saying that my paper was mistaken on this point is itself incorrect. Cau et al. (2017) state:

“The hyper-elongate neck of Halszkaraptor, countered by a less-elongated tail, suggests that its centre of mass was shifted anterior to the hip region.”

This statement and the skeletal reconstruction directly contradict the statement made in this paper that “ Cau et al. (2017) did not write that the unusual features in the caudal vertebrae of Halszkaraptor support a modified posture like that in birds: the latter was inferred on the basis of hypertrophied origin and insertion of the m. ileofibularis in, respectively, ilium and femur (Cau et al., 2017, supplementary information). Brownstein (2019) thus misinterpreted two distinct and unrelated sentences in Cau et al. (2017), one about the peculiar features of the caudal vertebrae (not related to tail elongation/reduction), and another about the pelvic and femoral adaptations supporting hip-extension.”

209—306: The author critiques my paper for not providing any morphometric analyses to back up my statement that the morphometric analyses presented in Cau et al. (2017) were flawed. The major issue here is that Cau et al. (2017) claimed that their morphometric analyses allied the forelimb of Halszkaraptor with those of plesiosaurs. As is shown in one of the figures in my paper, the forelimb of Halszkaraptor looks absolutely nothing remotely like those of plesiosaurs, so any morphometric analysis that found the two to be similar based on proportions of the particular long bones is inherently flawed. To illustrate this further, a human humerus and the humerus of some species of bat might have a similar length to width ratio, but just because this means they plot together in a morphometric analysis does not by any means say that the biomechanics of the bones are similar. This argument presented in Cau et al. (2017) for the functional anatomy of Halszkaraptor is supported by no morphological evidence.

Another issue is that the “unusual flattening” of the ulna in Halszkaraptor that the author claims is supported by the morphometric analyses conducted in the original paper and in this one is not in fact supported by any of these analyses. The two morphometric analyses conducted herein only plot mid-shaft width against total ulnar length, which could be taken to suggest something about the mid-shaft robusticity of the ulna but not anything about how this bone is flattened. A third variable factoring in both mid-shaft width measurements would need to be measured to get the morphometric analyses to support the arguments made.

The author's claim that my critique of this section of the original paper is invalid because I did not conduct morphometric analyses and instead relied on the gross dissimilarity of the forelimb of Halszkaraptor to that of plesiosaurs or wing-propelled birds is not supported. It is important to note the forelimb of wing-propelled birds is highly simplified relative to that of Halszkaraptor. The forelimb of a penguin, for example, is simply not highly comparable to Halszkaraptor, which has the classic three-fingered, clawed manus and elongate humerus, radius and ulna seen in non-avian coelurosaurs. Finally, the author fails to mention that the long axis of the ulna lies perpendicular to the vertical axis of the holotype specimen, along which it may have been deformed. On the whole, there is no strong evidence presented by this study or Cau et al. (2017) supporting a highly distinctive ulnar morphology in Halszkaraptor.

308—328: This section also attempts to discredit the rebuttal on the basis that it refutes statements that are irrelevant to inferring an aquatic ecology in Halszkaraptor. Although the author correctly points out that pachyostosis is not necessary for an aquatic ecology, the extreme adaptations for an aquatic life in Halszkaraptor, which are compared to those seen in crocodylians, aquatic turtles, and aquatic birds like Cygnus, mean that this aspect of the anatomy of Halszkaraptor ought to be considered. In aquatic birds like penguins and in crocodylians, a thickened layer of compact cortex along the periphery of bones is present (Houssaye et al., 2016). The comparison was therefore warranted. Furthermore, the comparison made between Halszkaraptor and pelicans is unjustified for several reasons. Pelicans and other flying birds possess a number of adaptations in the forelimb. The forelimb of pelicans is simplified and shows far more fusion than that of Halszkaraptor. These issues also confound direct comparison between Halszkaraptor and other marine birds. Halszkaraptor was suggested to possess an undulatory and/or forelimb propelled swimming mode, so the comparison made in this paper with pelicans mischaracterizes what was said in the original study. The author mischaracterizes an argument presented in the rebuttal by saying I said “vertebrates with hollow long bones and a highly pneumatized postcranial skeleton could not be adapted to some aquatic lifestyle, and [that I implicitly claim[s] that pachyostosis is a necessary requisite for a semiaquatic lifestyle.” The comparisons made were meant to go above and beyond what was originally said in Cau et al. (2017). So, the point made by the author here is irrelevant to the discussion.

330—350: The morphometric analysis and discussion presented by Cau et al. (2017) shows they argued the manus of plesiosaurs was similar to Halszkaraptor. Simply put, these skeletal elements look nothing like each other, and the assertion by the author that there is any morphological similarity between the two flies in the face of comparative anatomy. The suggestion that the anteriormost phalanges dictate the essential nature of the functional morphology of the manus is demonstrative that this section aims to defend a very poorly construed argument. Simply put, the manus of Halszkaraptor is not paddle-shaped, nor does it display hyperphalangy or extensive fusion and simplification as in two of the semi-aquatic and aquatic lineages with which it was explicitly compared in the morphometric analyses conducted by Cau here and in Cau et al. (2017). The manus of Halszkaraptor includes three digits tipped with sharp, curved unguals, the morphology seen in all other coelurosaurs. That the third finger is slightly aberrant is not indicative of anything, given that some of the few basal members of other derived coelurosaur clades we know of also possess bizarre manual digit proportions and digit proportion changes are well-documented among almost ever coelurosaur clade.

351—360: See the points made above.

362—374: This paper and Cau et al. (2017) are almost entirely focused on showing the anatomy of Halszkaraptor deviates markedly from other dromaeosaurids and paravians. Assuming that this argument is correct, there should be no reason to infer phylogenetic bracketing will tell us anything useful about the forelimb. This is picking and choosing which features ought to be reconstructed as distinctive or not distinctive. This is an especially important point to make given that the author considers the forelimb of Halszkaraptor to be highly aberrant rather than representative of several evolutionary transitions, although this is also not strongly supported by the anatomical evidence at hand.

376—384: I appreciate the use of morphometric analyses to support this point. However, a comparison of the foot of Halszkaraptor with the foot of a derived dromaeosaurid like Deinonychus shows the pedal ungual II of the latter was far larger and more developed relative to the other unguals. The morphometric analysis performed just shows that there is a linear relationship between log femoral length (a proxy for body size) and log ungual length. This is simply expected, as bigger animals will have bigger bones. What the author fails to do is compare the proportions of II-3 with the rest of the foot, which is the area of interest. The hypertrophied nature of dromaeosaurid pedal ungual II-3 primarily has to do with its size and extremely curved morphology relative to the other unguals of the foot. The plot seems to actually support the larger size of the pedal ungual II-3’s of derived dromaeosaurids compared to other paravians, especially if one remembers that a non-log-transformed version of this plot would show far more distance between the bin consisting of Halszkaraptor and other basal dromaeosaurids and paravians and that consisting of derived dromaeosaurids. The pedal ungual II of Halszkaraptor is also clearly not as heavily recurved as the same bone in more derived dromaeosaurids, including eudromaeosaurs.

432—459: The author suggests the data matrix I provided did not lead to the same phylogenetic topology I found when tested, yet I could not find in the supplementary information the tree that shows this. In any case, the phylogenetic topology I found in my rebuttal does not really differ at all from the topology found by Cau et al. (2015) or Cau et al. (2017), so I am unsure what dramatic problem the author has with the results I presented in my rebuttal of Cau et al. (2017). Furthermore, the author recovers the same sister-taxon relationship between Unenlagiinae and Halszkaraptorinae in the dataset they use. So, there is pretty much no distinction between the results I presented and the results presented here as far as the phylogenetic resolution and placement of Halszkaraptorinae is concerned, and this section, which claims to disprove my phylogenetic results, in fact supports them by finding the key relationship between Halszkaraptorinae and Unenlagiinae.

474—483: See above for why these arguments are not justified. None of the codings of Cau et al. (2015) and Cau et al. (2017) were changed in the analysis of Brownstein (2019), so the arguments made here do not in fact address the results of the latter study. If anything, the fact that very slightly different supports are found for particular clades in this matrix suggests the coding in Cau et al. (2017) may be sensitive such that slight differences in how analyses are run on the dataset produce significant differences in topology (although what major differences found are not clarified by the author here).

484—491: The author presents a list of 17 features that they state I mentioned in my original rebuttal or that they suggest are relevant to the development of the halszkaraptorine body plan. However, a careful review of these features suggests that the optimization results may actually be artifacts of the poor fossil record of basal members of many maniraptoran clades instead of synapomorphic to Halszkaraptorinae. The features discussed in my review include 2, 3, 4, 5, 6, 9, 14, and 17. Of these, only 3, 5, 6, 9, and 14 are found to be novel in halszkaraptorines, and 5, 6, and 9 are found to be homoplastic with respect to other maniraptorans and coelurosaurs. 14 should be considered a dubious character at best, because it describes the development of a process, and not the presence of the process itself. Although the development of the process might be important to the soft tissue anatomy in this region, the analysis fails to provide a justification for the level of aberrancy in this feature. Character 3 might be more strongly supported, although it is important to note that basal members of Therizinosauroidea and Oviraptorosauria are poorly characterized as of now, and little is known of the skull material of early members of these groups. The most basal therizinosaurs for which the premaxillae are known already possess edentulous premaxillae (Pu et al., 2013), and definite basal oviraptorosaurs already show highly specialized premaxillary dentition (Balanoff et al., 2009). Features 7, 8, and 12 are considered plesiomorphic with respect to maniraptorans and higher clades. In sum, the character state optimization results provide dubious support at best for the author’s assertion that many of the features of contention in Cau et al. (2017) and Brownstein (2019) are novel in Halszkaraptorinae. In this light, the paragraph starting on line 484 grossly overstates the results in the favor of the argument proposed by the author in this and other papers.

494—501: As noted in my comments above, this paper frames the rebuttal as incorrect based on
misrepresentation of the contents of the arguments presented in the original paper and my rebuttal. Many of the errors the author notes for my paper are actually either disagreements the author has with the homologous nature of features on Halszkaraptor, incorrect assertions, or discuss minor issues that do not affect the main arguments of the rebuttal study.

502—507: The statement made here is not reflective of what was said in Cau et al. (2017), who compared the limb anatomy to those of plesiosaurs using morphometric analyses, and suggested Halszkaraptor possessed a number of traits that they interpreted to represent adaptions for a piscivorous and aquatic lifestyle. Cau et al. (2017) provided two contradictory aquatic locomotory mode hypotheses for Halszkaraptor: forelimb-assisted swimming and undulation. Cau et al. (2017) state:

“The horizontally oriented zygapophyses in the neck and tail vertebrae of halszkaraptorines would have permitted the axial undulatory swimming mode that is typical of taxa with axially elongated body shapes”

Here and elsewhere in the original paper, Cau et al. (2017) repeatedly attempted to ally Halszkaraptor with fully aquatic or amphibious taxa in their study. Therefore, the author’s assertions in the discussion paragraph misrepresent the original paper in an attempt to discredit mine. Statements like “Cau et al. (2017) did not suggest such an extreme form of aquatic adaptation in H. escuilliei” and “Given that Cau et al. (2017) did not suggest a “partially marine ecology” [sic] for Halszkaraptor, and did not suggest a plesiosaur-like locomotory style or a plesiosaur-like forefin morphology in Halszkaraptor, it is unclear why Brownstein (2019) had focused to that peculiar fully-aquatic bauplan” are false, as Cau et al. (2017) state:

“The unusual morphology of Halszkaraptor suggests a semiaquatic ecology”

“The unusual forelimb morphology is not inconsistent with a semiaquatic ecology”

“Morphometric comparison of the forelimb of Halszkaraptor with those of terrestrial, aquatic and flying sauropsids supports the idea that this theropod possessed swimming adaptations”

“instead, the proportions of Halszkaraptor cluster with those of long-necked aquatic reptiles”

“Halszkaraptor is interpreted as an amphibious theropod: an obligatory biped on land and a swimmer that used its forelimbs to manoeuvre in water and that relied on its long neck for foraging”

The rebuttal never stated that Cau et al. presented Halszkaraptor as a fully aquatic animal, and referred to their hypothesis as suggesting H. escuilliei was partially marine or semiaquatic in ecology. This mischaracterization of the rebuttal, which does not say Halszkaraptor was fully marine or aquatic, and the original paper, which compares Halszkaraptor with fully and semiaquatic taxa, serves only to strengthen the assertion that the arguments presented in the rebuttal are flawed by attacking their relevance to the original argument. As the quotes above show, the rebuttal paper’s aims were indeed relevant, and the author’s words mischaracterize both what was said in the original paper and in the rebuttal to benefit their argument.

513—516: This sentence encapsulates a major issue with the original paper. In providing support for the hypothesis that Halszkaraptor was semiaquatic, Cau et al. allied the forelimb, cervical vertebrae, skull, and other bones of Halszkaraptor to semiaquatic and fully aquatic animals. My rebuttal attempted to show this comparisons did not ally Halszkaraptor with semiaquatic or aquatic taxa. Suggesting that just because some of these features are absent does not mean Halszkaraptor was not semiaquatic is equivalent to admitting the paucity of evidence for the ecological mode. The null hypothesis is that Halszkaraptor had the same ecology as any other theropod, whereas the author’s discussion assumes the null hypothesis is that Halszkaraptor is aquatic. This is an incorrect assumption, but is largely what this paper and the original one are predicated on.

524—541: See my previous comments on the strength of the discussion using the new optimization results.

541–543: Six of the seventeen features assessed are apomorphic to Paraves or larger clades, and a number of other features that the author suggests are homoplastic may reflect biases in the number of basal members of paravian lineages known. This sentence overstates the results.

Discussion:
This section provides an overview of what the author suggests was accomplished in this paper. Many of the points outlined above are relevant for understanding why this section incorrectly represents the issues of contention and the arguments made in the original paper and rebuttal.
As noted, many of the features the author says are strongly supported as peculiar synapomorphies of Halszkaraptorinae are in fact dubiously distinctive and/or poorly supported as independently developed in that clade. For example, whether the development of the supratrochanteric process is particularly important for the development of a semiaquatic body plan in Halszkaraptor is not supported, nor is the extreme aberrancy of this feature relative to other paravians. In large part, the discussion section backtracks from the original study in an attempt to mount an assault on the rebuttal.

The author presents a new feature, the size of the anteriormost premaxillary teeth, as further evidence of an aquatic ecology, comparing this feature to that seen in spinosaurids and semiaquatic crocodylians. The author misses that the "festooning pattern" where the anterior premaxillary teeth are much smaller is present in a huge number of other coelurosaurs, including tyrannosauroids (e.g., Sereno et al., 2009, Fig. 1), basal troodontids (Xu and Norell, 2004), basal alvarezsaurs (Choiniere et al., 2014, Fig. 12) and others.
The author is correct that the small size of the anterior premaxillary teeth of Halszkaraptor is unlike the condition in derived dromaeosaurids like Saurornitholestes or Velociraptor, but the widespread nature of this feature among clearly terrestrial coelurosaurs shows this feature is not at all indicative of a semiaquatic ecology. The author's attention to this anatomical feature is demonstrative of a major flaw in the arguments presented here. Principally, the widespread nature in Coelurosauria of many of the features in Halszkaraptor deemed indicative of a semiaquatic ecology in that taxon suggest these features are not drastically different from what is seen in terrestrial coelurosaurs. Many of these features may even be homologous and this study and the rebuttal show, and so there is no reason to say comparisons with semiaquatic taxa are indicative Halszkaraptor was semiaquatic when the very features discussed in these comparisons are actually present (in combinations in some cases) in many of Halszkaraptor's relatives along the coelurosaurian tree.

On the whole, this paper attempts to rebut my rebuttal of Cau et al. (2017) by claiming numerous minor issues supposedly exist within my paper that render its argument meaningless. As I’ve stated above, these critiques break down into two main types. The first includes minor statements that in most cases are predicated on the author’s own terminological definitions and assumptions about theropod anatomy, of which almost all are incorrect or poorly substantiated. The other include poorly construed arguments based on poor or simply absent morphological evidence. Although I think that some parts of this paper are worthy of publication, the majority of this work succumbs to these issues. However, I think many good points are also made in this paper, and I suggest the author focus on the one’s I’ve highlighted.

Regards,

Chase Brownstein
Research Associate,
Stamford Museum and Nature Center

References.
1. Cau, A. et al. Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs. Nature 552, 395–399 (2017).
2. Ibrahim, N. et al. Semiaquatic adaptations in a giant predatory dinosaur. Science 345(6204), 1613–1616 (2014).
3. Conti, MA, et al. Jurassic dinosaur footprints from southern Italy: footprints as indicators of constraints in paleogeographic interpretation. Palaios 20.6 , 534-550 (2005).
4. Charig, A. J. & Milner, A. C. Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Nat. Hist. Mus. Lond. Bull. 53, 11–70 (1997).
5. Sereno, P.C., et al. A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. Science 282 (5392), 1298–1302 (1998).
6. Zanno, L. E. & Makovicky, P. J. Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution. Proc. Nat. Acad. Sci. USA 108, 232–237 (2011).
7. Evans, D.C., et al. A new dromaeosaurid (Dinosauria: Theropoda) with Asian affinities from the latest Cretaceous of North America. Naturwissenschaften 100(11), 1041–9 (2013).
8. Xing, L. et al. Piscivory in the feathered dinosaur Microraptor. Evolution 67, 2441–2445 (2013).
9. Hendrickx, C., et al. A proposed terminology of theropod teeth (Dinosauria, Saurischia). Journal of Vertebrate Paleontology, 35(5), e982797 (2015).
10. Brownstein, C.D. (2019). Halszkaraptor escuilliei and the evolution of the paravian bauplan.
Scientific Reports 9:16455.
11. Houssaye, A., et al. Adaptive patterns in aquatic amniote bone microanatomy—more complex than previously thought. Integrative and Comparative Biology, 56(6), 1349-1369 (2016).
12. Cau, A., Brougham, T. & Naish, D. (2015). The phylogenetic affinities of the bizarre Late Cretaceous Romanian theropod Balaur bondoc (Dinosauria, Maniraptora): dromaeosaurid or flightless bird? PeerJ 3, e1032.
13. Pu, H. et al. An Unusual Basal Therizinosaur Dinosaur with an Ornithischian Dental Arrangement from Northeastern China. PLoS ONE 8(5), e63423 (2014).
14. Balanoff, A. M., Xu, X., Kobayashi, Y., Matsufune, Y. & Norell, M. Cranial Osteology of the Theropod Dinosaur Incisivosaurus gauthieri (Theropoda: Oviraptorosauria). Am. Mus. Nov.3651, 1–35.
15. Sereno, P.C. et  al. Tyrannosaurid skeletal design first evolved at small body size. Science 326 (5951): 418–422 (2009).
16. Choiniere, J. N., et al. Cranial osteology of Haplocheirus sollers Choiniere et al. 2010 (Theropoda, Alvarezsauroidea). Am. Mus. Nov. 3816, 1–44 (2014).


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: THE BODY PLAN OF HALSZKARAPTOR ESCUILLIEI (DINOSAURIA, THEROPODA) IS NOT A TRANSITIONAL FORM ALONG THE EVOLUTION OF DROMAEOSAURID HYPERCARNIVORY
Review round: 1
Reviewer: 3

Output:
Basic reporting: No comment.
Experimental design: No comment.
Validity of the findings: The one area that I think can be improved is to provide some form of definition of the degree of aquatic lifestyle of Halszkaraptor. This causes issues both in this paper and in the commentary from the response paper meaning that there is a lack of clarity in some of the arguments when it's not obvious what the author means. A bit more on the details of the apparent convergences with spoinosaurs and adaptations to this lifestyle would also help. I appreciate these are not core to the central ideas of this paper but they do crop up repeatedly here and spelling out some of these arguments would be very useful here and going forwards.
Additional comments: Please see the marked up document for various suggested additions and corrections.


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: THE BODY PLAN OF HALSZKARAPTOR ESCUILLIEI (DINOSAURIA, THEROPODA) IS NOT A TRANSITIONAL FORM ALONG THE EVOLUTION OF DROMAEOSAURID HYPERCARNIVORY
Review round: 2
Reviewer: 1

Output:
Basic reporting: See below.
Experimental design: See below.
Validity of the findings: See below.
Additional comments: Review of “The body plan of Halszkaraptor escuilliei (Dinosauria, Theropoda) is not a transitional form along the evolution of dromaeosaurid hypercarnivory” by Andrea Cau

Dear Dr. Knoll,

Thank you for allowing me to review this paper. I want to thank the author for rigorously responding to my previous comments and for clarifying/correcting when discussing particular features. However, I am still unconvinced of the findings, primarily because the author’s analyses either still do not in fact find fault with several of the points made in the rebuttal paper or themselves are, in my understanding, improperly performed for testing the anatomical hypotheses relevant to this debate. I apologize for being a bit difficult here, but I am still unconvinced by the findings presented in this and the original paper, and I feel as though many of the supposed similarities between Halszkaraptor and semiaquatic taxa are still poorly substantiated or not fleshed out. I do feel there might be a way forward for this paper, but not as it is currently framed. In short, there are serious issues with the inferences made here about comparative anatomy. Please see my detailed notes below for comments on some of the more important issues.

Firstly, the author continues to argue that the expansion of the rostrum in Halszkaraptor is sufficiently distinctive from other maniraptorans and coelurosaurs to suggest the feature in the former is not homologous with rostral expansion in members of those larger clades. The author differentiates the condition in Halszkaraptor into two features, the “remarkable anteroposterior elongation and dorsoventral flattening of the prenarial region of the premaxilla, which also results in the posterior placement of the narial region relative to the snout anterior tip.” Figure 2 clearly demonstrates, however, that the lateral expansion of the premaxillae found in therizinosaurs, ornithomimosaurs, and some other coelurosaurians is also present in Halszkaraptor. The author states in the rebuttal that the key feature here is the posterior retraction of the nares in Halszkaraptor, and so the issue is that the combination of these features produces the distinctive condition. Right now, both the author and I are in apparent agreement that at least half of this combination can be found widely among maniraptorans and coelurosaurs along the lineage to Paraves and within it, Dromaeosauridae. As I’ve noted in my previous review, I would be very, very cautious in inferring the distinctiveness of the posterior retraction of the premaxillary narial margin in Halszkaraptor. Looking at the holotype of Mei long, a very basal troodontid that we expect might look somewhat like basal dromaeosaurids based on the phylogenetic evidence, the narial margin of the premaxillae is posteriorly retracted (Fig. 2 in Xu and Norell, 2004). This may have to do with distortion of an apparently three-dimensionally preserved, complete specimen (reminiscent of Halszkaraptor, although the holotype of Mei shows arguably better preservation) (see Gao et al., 2012 for another specimen). So, not only is half of the combination noted here clearly not distinctive, but another key part of it might have to do with distortion or might even be present in a similar fashion in close relatives to basal dromaeosaurids. Repeat for the “dorsoventral flattening,” for which the author has not considered distortion as a factor. In any case, the apparent aberrancy noted for this part of the anatomy of Halszkaraptor remains unsubstantiated. I believe the author should talk about this feature, but only with the context of larger maniraptoriform anatomy.

Continuing with the discussion of narial retraction, the author states that there is “no a priori reason” for Halszkaraptor to show a narial morphology similar to eudromaeosaurs. The author here is clearly rebuttng my examples of eudromaeosaurs not showing the condition reconstructd for Halszkaraptor. The issue is that microraptorans also do not have a longer nasal margin of the naris than premaxillary margin (see Fig. 4 in Gong et al., 2012; Fig. 3 in Pei et al., 2014). Since we do not have unenlagiine skulls where this region is well-preserved yet, there is absolutely no phylogenetic support for the reconstruction made in Cau et al. (2017). The author notes that narial elongation is not relevant to the issue at hand, and rightly states that the posterior narial margin is not preserved for baronychine spinosaurs. Firstly, I would argue (as I have) that narial elongation is relevant, as this condition is clearly present in baronychine spinosaurs and might have to do with how soft tissue ought to be reconstructed for these animals. Without very close to exact morphological similarity in this feature between H. escuilliei and spinosaurids, I have a very tough time buying the argument made here. Furthermore, without any substantial support for the nasal condition in Halszkaraptor being substantially different from other maniraptorans and coelurosaurs (see here, above, and in the following discussion), there is not any scientific reason to compare the skull with spinosaurids. This is essentially “jumping the shark” when it comes to comparative anatomy/functional morphology, and here it is done without a shred of support from any biomechanical analysis. The nostrils of Halszkaraptor might have been slightly more posteriorly placed in life than other dromaeosaurids, but whether this condition reflects a substantial leap in ecomorphology (as the author suggests and has suggested based on their speculation of the locomotory abilities of Halszkaraptor) remains unsubstantiated.

The author suggests I contradicted myself by comparing the premaxillae of Halszkaraptor to the premaxillae of basal maniraptorans we do have and then suggesting the sample size of basal maniraptoran premaxillae was too small for such comparisons to be made well. As I stated in my previous review, the burden of evidence was on Cau et al. (2017) to provide conclusive comparisons demonstrating the strong aberrancy of features like the distribution of foramina on the premaxillae. I thank the author for clarifying that the combination of the distribution and number of foramina is what distinguishes Halszkaraptor. As the author notes, this is not exactly what was said in the original study. However, the point remains that the claim about the foramina count increasing on the premaxillae of Halszkaraptor requires far more material be found before this can be leaned on as a feature informative for discussions about that taxon’s ecology. In any case, claiming in this paper that Brownstein (2019) is blatantly incorrect for noting this feature is misleading.

The point about tooth replacement rates is well-taken. Thank you for clarifying this important distinction.

The author has claimed in their rebuttal paper that the reason that they only focused on comparing Halszkaraptor to long-necked marine reptiles and birds was because of cervical morphology, and not the elongate necks themselves. However, this point is not clarified at all in Cau et al. (2017). Cau et al. (2017) do state that the cervicals of Halszkaraptor are allied to the cervicals of long-necked marine taxa in several ways, but this comes under the implicit assumption made in that paper that long-necked taxa ought to be compared with each other. The author validates this point by saying they also examined giraffes. Furthermore, when Cau et al. (2017) presented morphometric analyses allying Halszkaraptor with plesiosaurs and other long-necked marine reptiles, the intention made was to compare Halszkaraptor to long-necked aquatic and semiaquatic taxa. This section in this paper therefore misrepresents what was actually said in the original paper, and improperly suggests that the rebuttal paper was at fault for discussing a feature that was incompletely discussed/explained in the original manuscript. The question of how the argument was advanced in Cau et al. (2017) is the one considered here, not about whether Halszkaraptor should or should not be compared with long-necked species. Furthermore, the authors of Cau et al. (2017) also failed to compare the elongated neck of Halszkaraptor with non-paravian coelurosaurs, as noted in the rebuttal and indirectly in this paper.

On the point about the absence of extensive lacustrine, fluvial, etc. environments fitting for an aberrant, semiaquatic, forelimb-propelled or neck-undulating swimming dinosaur, the author agrees that only one other vertebrate in the Djadokhta fauna shows any sign of being semiaquatic. Furthermore, the author fails to mention that Shamosuchus djadochtaensis
 possesses an exceptionally short and narrow relative to other members of that genus, which is exactly the opposite of what is seen in baryonychine spinosaurs and Halszkaraptor . Nonetheless, the author goes on to describe several morphological similarities between Halszkaraptor and Shamosuchus as evidence of the semiaquatic ecology hypothesis for the former. This act is demonstrative of many superficial comparisons made in Cau et al. (2017) and this paper that do not accurately and effectively reflect the sum total morphological evidence. The author then goes on to cite a paper from the 1970s that reports lacustrine settings for part of the Djakhota. Please refer to my previous review and the citations in the rebuttal paper for a more recent, up-to-date discussion of Djakhota paleoenvironments. Given that the putative semiaquatic dinosaur Spinosaurus, which is the only other dinosaur besides Halszkaraptor for which supposed substantial adaptations for swimming have been described from the body and hindlimb, lived in a giant deltaic ecosystem, the question of the paleoenvironment of Halszkaraptor is still important to consider, and is not addressed in this paper with only a handful of at best dubious pieces of evidence.

On the issue of dentary bulge morphology, I can confirm that the feature reported in Evans et al. (2013) is the same I noted as a “chin.” The confusion here stems from the fact that, as Evans et al. (2013) report, this “chin” is poorly developed in Acheroraptor. It is heavily developed to form a bulge that also stems from this divergence in Velociraptor and Bambiraptor, as the figure in the rebuttal paper shows. Therefore, the author here misconstrued what was said in the original review. Since the morphology described for Halszkaraptor in the original paper is consistent with this feature in other dromaeosaurids, the note made in this paper is a clarification, and not a correction.

The issue of the rebuttal paper using the term “unserrated ziphodont” to describe the teeth of Halszkaraptor is not only a non-issue, but also misreports the etymology of the term, its history in the literature, and is employment in the rebuttal paper. This is done not out of a need to correct an egregious error in the original paper, given that unserrated theropod teeth have been described as ziphodont before (e.g., Hendrickx et al., 2015). Langston (1975) does indeed use the term, but he does not actually define it as having to do with serrated teeth! Ziphodonty in crocodylians has to do with whether their teeth are dinosaur-like (e.g., not conical). Furthermore, Langston (1975) provisionally credits Marsh (1871) with introducing the term. Brochu (2013) says that Langston (1975) said that serrated teeth are key to ziphodonty, but all Langston said is that Marsh was “impressed” with the recurved, mediolaterally compressed, and serrated teeth of some crocodyliforms. In fact, Langston and Marsh were using the term correctly, because, contra the author, ziphodont derives from a type of Iron Age sword with smooth edges described in Ancient Greek texts. Langston (1975) defines ziphodont on the first page of his paper as “the vernacular derived from the taxon ziphodon … proposed by O.C. Marsh for a species of dinosaur-toothed crocodilians from Wyoming. The term is descriptive of the principle distinguishing character state of this group of crocodilians and is less clumsy and more precise than the term “dinosaur-toothed” previously employed.”

So, the author here incorrectly characterizes the literature and repeats the incorrect use of this term in order to show a minor issue supposedly exists in the terminology of the rebuttal paper. Not only is this argument incorrect as I have shown it to be, but it also clearly is not scientific in origin. The term could be understood in the rebuttal paper even if serrations were integral to the term ziphodont as used in modern paleo literature. I can only assume that this section was included in order to demonstrate the inferiority of the rebuttal paper textually, which is not an attack on the science. The attempt to frame the rebuttal paper here as inaccurate because of small terminological issues unfairly benefits the author’s position on the issues at hand.

On the subject of the extension of distal end of the caudal series in H. escuilliei, it is clear from the published figures that, even though it is incomplete, the elongation of the tail in this taxon did not approach that seen in other dromaeosaurids and even other paravians. In the rebuttal letter, the author also notes the distinctiveness of some of the features of the caudals of halszkaraptorines relative to other dromaeosaurids. In any case, the fact that this feature is clarified as not being strongly involved in the new stance is the important thing, and so this whole section can be reduced to saying this.

On the issue of convergence between the digit proportions of plesiosaurs and Halszkaraptor, I will again state that any paper that suggests some sort of biomechanical similarity between a functional paddle and a classically coelurosaurian hand is simply incorrectly stating the anatomy. Regardless of what the morphometric analyses found with respect to relative lengths, there is no logically sound way of equating the morphology of the hand of Halszkaraptor with the manus of plesiosaurs and other marine reptiles. Nor should you draw comparisons with forelimb-propelled diving birds, which show extensive fusion and simplification in their forelimbs. Not only do the morphometric analyses in Cau et al. (2017) point to logically fallible comparisons, but they also (as stated in Brownstein (2019)) imply contrary locomotory modes, especially when the fact that Cau et al. (2017) seem to suggest H. escuilliei used its neck in undulatory locomotion is considered. The author may wish to include this section rebutting the rebuttal paper in further drafts of the manuscript, but I will continue to warn that this is simply poorly-performed comparative anatomy. That the author claims that the absence of a morphometric analysis in Brownstein (2019) testing those in Cau et al. (2017) implies the strength of the former is incorrect. Simply put, Halszkaraptor essentially has the same manual anatomy as any other coelurosaur.

On the issue of the ulna, the author has refused to conduct an additional morphometric analysis with the correction suggested, saying that mediolateral diameter has been considered a sufficient variable to test ulnar flattening in previous papers. Not only does the author not cite any particular papers, but this is simply incorrect geometrically. “Flattening” refers to the mediolateral width vs. the anteroposterior width. An ulna could be extremely robustly-built and have a short length and high mediolateral width value, and vice versa. What you need to test is how thin anteroposteriorly the ulna is relative to how wide it appears in dorsal and ventral views.

The author responded to my critique of the forelimb of Halszkaraptor being functionally equated to a paddle by saying that “There is not provided evidence that the complexity of the appendicular skeleton is relevant in shaping the morphologies discussed in this manuscript. In particular, note that many taxa with different phalangeal formulae and degrees of element fusion have converged independently to a flipper-like morphology.” The issue with this statement is that, in order for Halszkaraptor to be properly likened to these taxa, the major differences in anatomy must be considered.

On the point about pachystosis, the author claims “extreme” adaptations for a semiaquatic lifestyle were not claimed for Halszkaraptor, even though they refer to the features of the body plan they linked to such an ecology as aberrant novelities. Cau et al. (2017) claimed that Halszkaraptor was a piscivore with a highly modified rostrum that could use its neck and forelimb to locomote through the water and had a new walking stance on land. That is a highly derived ecology. In this way, the examination of possible pachystosis in Halszkaraptor using the data provided in the original study is important, especially since spinosaurids also developed this feature.

A significantly shortened first finger relative to the other two digits is found in a variety of paravians and basal avians. See Archaeopteryx. There is no evidence provided that this feature should not be expected in an early-diverging dromaeosaurid.

The digit II ungual of Halszkaraptor is clearly not as strongly recurved and developed as the same bone in derived dromaeosaurids, such as Deinonychus, Dakotaraptor, and Utahraptor. A simple comparison of the bone in Halszkaraptor with these shows the derived morphology is distinctive. The point about the non-log transformed analysis was not a recommendation to conduct one (which as the author notes should not be done), but instead to illustrate this issue. Some dromaeosaurids might have longer upper hindlimbs than others. What the author needs to test is the relative pedal proportions.

The three topological differences found in the rebuttal paper’s phylogeny were a sister taxon relationship between Halszkaraptorinae and Unenlagiinae and some polytomies of larger fasmilies early in maniraptoriform evolution. Contrary to the author, these several small differences are not “pivotal” to the results in the rebuttal paper, which aimed to show that the supposed adaptations for a semiaquatic ecology in Halszkaraptor were poorly interpreted and that some could be better explained as possible plesiomorphies of larger maniraptoran clades.
If the author is failing to replicate the results presented in the rebuttal, it must have to do with the matrix itself, as it was not changed from Cau et al. (2015).

On the subject of the optimization analyses, I will not repeat what I said in the previous review. Simply put, nearly half of the features considered are probably plesiomophies of larger coelurosaurian clades. Even if some of these were modified slightly in Halszkaraptor, there is not a reason to suggest they indicate a semiaquatic ecology in that taxon. The alternative scenario suggested in the rebuttal paper was one in which Halszkaraptor retained features plesiomorphic with respect to larger clades of coelurosaurian dinosaur. This analysis essentially supports that for several characters.

The author claims that the undulatory and forelimb-propelled swimming modes in Halszkaraptor do not conflict with each other. Without having gone through and carefully performed biomechanical analyses and reconstructions, without taking the time to assess whether these two locomotory modes found in dramatically different taxa would fit together in Halszkaraptor by means of quantitative study, it is unjustified for the author to claim any sort of conclusion on whether these modes could exist in this taxon together. There is not any quantitative evidence for the undulatory mode presented here or in the original paper.

On the issue of what “semiaquatic” means, I cite the commentary of the other reviewers, who also note that this term is used confusingly in Cau et al. (2017) and potentially misleadingly here.

On the size of the anterior maxillary teeth, this feature is also found in basal troodontids (e.g., Xu and Norell, 2004; Pei et al., 2017). In any case, the slightly smaller size of the anterior maxillary teeth should not be used to support any ecological change in a species of coelurosaur, as tooth counts and tooth size are so highly variable (even ontogenetically) that this evidence is dubious.

The author has added a section to the paper comparing Halszkaraptor to sawbills. This is all well and good, but is presented ad hoc as another example of convergence between the former and semiaquatic avians that is not supported by any comparative figures, quantitative analysis, etc.

Based on the points raised here and in my previous review, I am not ready to accept the arguments made here unless the author at least attempts to conduct some of the modifications to the quantitative analyses I propose. The severe methodological issues noted above must be addressed.

All the best,

Chase Brownstein
Research Associate
Stamford Museum and Nature Center


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: THE BODY PLAN OF HALSZKARAPTOR ESCUILLIEI (DINOSAURIA, THEROPODA) IS NOT A TRANSITIONAL FORM ALONG THE EVOLUTION OF DROMAEOSAURID HYPERCARNIVORY
Review round: 2
Reviewer: 2

Output:
Basic reporting: No comment.
Experimental design: No comment.
Validity of the findings: No comment.
Additional comments: No comment.


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: NOVEL ASSOCIATION BETWEEN TGFA, TGFB1, IRF1, PTGS2 AND IKBKB SINGLE-NUCLEOTIDE POLYMORPHISMS AND OCCURRENCE, SEVERITY AND TREATMENT RESPONSE OF MAJOR DEPRESSIVE DISORDER
Review round: 1
Reviewer: 1

Output:
Basic reporting: Please see the comments in the next section.
Experimental design: This study was designed to determine six SNPs in inflammatory-related genes associated with MDD occurrence, age of onset, and response to SSRI treatment.

Major comments and questions:
This study included 180 MDD subjects and 180 healthy controls. The subjects were selected randomly. However, the authors need to clarify whether this is a sex-age-matched control study. This is critical, because the study was not only designed to determine the “association” with the disease risk, but also study the age, and sex effects on the occurrence of the disease and treatment response. It is a population study, therefore, this is crucial to clarify the study subjects’ characteristics.  In addition, this will be a very important factor for data interpretation. In fact, 2/3 of patients with MDD are women, virtually in every MDD study.

The rationale of selecting these SNPs should be demonstrated in the manuscript.  It should not just because none of these SNP haven been studied in depression (line 275). In fact this is not a fair statement. A series of large MDD GWAS have been published over the years, and each of these immune gene might have implication in MDD pathophysiology or SSRI treatment response.  One of the major critiques for this manuscript is the selection of SNPs. In addition, it remains to be determined whether the findings can be replicated. Furthermore, this study does not provide any functional genomic data to show the biological impacts of the SNPs which reveal positive results in their study population. Therefore, this is a purely “association study” in a small population which fails to provide meaningful biology beyond the p values. I suggest that the authors should take advantage of published data ie, Nature Neuroscience volume 22, pages343–352(2019), or STAR*D study…etc which can be served as a replication study.
Finally, the conclusion seems overstatement and fails to be supported by their finding (line377).  “discovery about impact of selected SNP on treatment response could contribute to the selection of effective, personalized pharmacotherapy. On the whole, our results cast a new light on the pathogenesis of major depressive disorders”.

Line 181: Please clarify the statistic methods for data analysis. Why is that the authors used unconditional multiple logistic regression model to determine the association of the SNPs and the occurrence of MDD? What are they co-variants in these analyeis?

Line 264: treatment efficacy.  HAMD scores at baseline and 8 week treatment should be presented in the manuscript. In addition, with regard to treatment efficacy, it will be helpful to define as “ response (reduction from baseline of ≥ 50% in the total score) and remission (total HAMD-17 score ≤ 7), all of which seem more standard definition for treatment outcome.
Validity of the findings: Line 223: gene –gene interaction. These SNPs are within immune genes, and in differently inflammatory signaling pathways. I am not sure how the authors used one SNP in a gene to performed gene gene interaction and if these results are valid?
Additional comments: Minor comments and questions:

Line 31: standard nomenclature should be used throughout the manuscript. ie TGFA, TGFB
Line 37: a gene-gene analysis revealed a link between studied polymorphisms and depression. Please clarify if the analytical method is valid.
Lin83: od
Table 1: please correct and specify the location of each SNP included in the study, ie, which exon?  If it’s located in 5’ of the gene, it should be 5’ of X gene. ..etc. please use standard way to express gene structure.  It will be helpful for the readers if this table can include minor allele frequency for each SNP in European population from public database ie NCBI SNP!


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: NOVEL ASSOCIATION BETWEEN TGFA, TGFB1, IRF1, PTGS2 AND IKBKB SINGLE-NUCLEOTIDE POLYMORPHISMS AND OCCURRENCE, SEVERITY AND TREATMENT RESPONSE OF MAJOR DEPRESSIVE DISORDER
Review round: 1
Reviewer: 2

Output:
Basic reporting: In the present manuscript, authors evaluated the association of six polymorphisms in TGF-β1, IRF, PTGS2, TGF-α and IKBKB with depression, and antidepressant efficacy, in a total of 360 (180 patients and 180 controls) DNA samples, using TaqMan probes. Authors concluded that the studied SNPs might influence the risk of occurrence, age of onset, severity of depression and response to the antidepressant treatment.

#1 In general, the paper is easy to read, however it would benefit from a global typos, grammar and punctuation revision. E.g. lines 53, 93,96, 103, 123, 273.

#2 Background information is relevant, pertinent and allows understanding of the context. However, several sentences lack references. Please see lines 56 and 57 for instance. Additionally, reference 1 is incomplete.

#3 Structure is, in general, in agreement with Peer J guidelines.

#4 Regarding raw data, authors kindly provided it in the supplementary files 1.
Experimental design: Research is within scope of the journal, and research questions are well deﬁned and relevant. However, some methods need a better clarification/to be completed:

#1 Were depressed patients treated with the same SSRI (line 146)? It is not clear in the text.

#2 In Methods section authors say that DNA purity was controlled by acquiring absorbance ratio at 260 nm and 280 nm (lines 165-166). In which equipment was it determined?

#3 Since sample is not large, as referred by the authors, paper would benefit if the power of the study could be calculated.

#4 Authors calculate treatment efficacy thought a formula, which is display in results section (lines 262-263). It is not clear why they use this formula to calculate efficacy. Was it based in other study? The formula must be displayed in methods section, not in results section.

#5 An extensive statistical analysis was performed, however, and since six polymorphisms in TGF-β1, IRF, PTGS2, TGF-α and IKBKB were evaluated, the paper would benefit if correction for multiple testing (such as Bonferroni) could be performed.

#5 Figures and tables are relevant and provide with the quality, however tables 3- 4, due to its extension, would benefit if sent to supplementary materials.
Validity of the findings: Discussion is extensive, however I fell it needs a bit more detail. I suggest that you improve the justification for the impact of the studied polymorphisms with depression/antidepressant response, to provide a clearer justiﬁcation for your study.

#1 For example for TGF α and TGF β, I suggest you include the following papers to improve you discussion:
https://www.ncbi.nlm.nih.gov/pubmed/27049572
https://www.ncbi.nlm.nih.gov/pubmed/29237050

#2 In line 362, regarding IRF1 gene, authors concluded that AA carriers had a better treatment response. It is not clear why. Authors could provide a putative mechanism, supported in other studies, for these results.
Additional comments: No additional comments


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: MONITORING THE TRAINING DOSE AND ACUTE FATIGUE RESPONSE DURING ELBOW FLEXOR RESISTANCE TRAINING USING A CUSTOM-MADE RESISTANCE BAND
Review round: 1
Reviewer: 1

Output:
Basic reporting: In general, the manuscript is well written although it could do with one more edit as I found a few problems with the writing and clarity of wording. e.g. line 376 "bended" instead of "bent"; line 378 should be "did not" rather than"do not". There are a few others that I am sure the authors will identify with another read of the manuscript. "Theraband" is a trade name. Did you actually use "therabands" or some other tubing.

I thought the study was well conducted and showed some good internal validity, especially in determining the training loads using "Thera-bands". This was carefully controlled in the experimental setting. However, when most home-based programs are prescribed the patient is given a "Theraband" usually of a specific colour and expected to do the exercises at home. They are able to set their own tension based on how much band they work with. So your study is much more precise in setting the work load or resistance. Would you expect this approach be applied in a practical setting? You may wish to comment on this aspect of the study and its practical application. However, my main concern is the lack of clarity of the actual study as the main purpose seems to get lost in a number of peripheral questions. It seems to me the main purpose is to see if "patients" can follow a prescribed home-based program on strength training or rehabilitation. In order to do this you have devised an instrument that potentially can be used by a therapist to check if the patient has followed a prescribed program. The study shows that the instrumentation you devised is able to show the different phases of muscle contraction such as concentric, eccentric, isometric and the rest periods using the algorithm you developed. What is less clear to me is the question of whether the subjects followed the prescribed program. In fact, I could not find if an actual program was prescribed. There is some reference a metronome was used but not sure if this was in the familiarization session or the subjects were allowed to use it when theoretically doing the exercises by themselves. Normally when prescribing a program for strength, the resistance is set and a number of repetitions related to the % of the 1RM along with a tempo for the various segments of the contraction. In this study the program seems to consist of  intermittent sub-maximal contractions (ISC) repetitions at a set load for 5 min, then a 1 min rest, followed by another 2 min. There appears little direction in regard to the tempo or repetitions. Were the subjects directed to resist the lengthening or eccentric phase? It seems to me a more ecologically valid study would be specific in prescribing a program and seeing if patients were able to follow it and this would be the crux of the question. Or have I missed something? Please clarify  if this is the case.

I did have a lot of trouble relating the text to the figures. It would have helped to have clear figure captions as well as the number of the figure shown on the actual figure. I am not sure if this is a journal requirement but from a reviewer perspective it would make it much easier to find the appropriate figure when reading the text. I ended up having to count the figures as well as scroll down a number of times. Do you need all the figures and tables. I think you could reduce the number if you narrowed the focus of the study and concentrated on the main purposes.
Experimental design: You provide a good rationale for the study and the need to be able to assess the compliance of patients in following prescribed programs to regain or increase their strength. The case is particularly made for an older demographic so I was surprised when you used subjects between 22 and 34 years of age. If your interest is in an older cohort why did you not use older subjects? Older subjects will respond very differently to a younger population in regard to exercise and force application.

I also feel a lot of the discussion related to age, gender, and weight is limited based on the number of subjects and does not add to the main purpose of the study. I appreciate the fatigue discussion is interesting and from a training perspective is important but not sure if it is relevant to the main purpose of the study unless you provide a stronger rationale for its inclusion. You seem to think it is a negative component whereas many researchers believe fatigue is the stimulus for muscular adaptation. So to me this could be an important variable to monitor related to compliance.

You examined both hands in the study. Did you have a specific reason for doing this? Did you change the order of testing and if not could this have an impact on your findings?
Validity of the findings: In your discussion you report on the comparison of TUT between the algorithm and the two assessors but not on the agreement related to the segments of the contraction. Did you examine this aspect and if so how well did they agree? You also refer to TUT as the "gold standard" (line 388). I am not sure what you mean by this statement. Please explain.

I do appreciate you provide a lot of detail on the algorithm but must confess to not really understanding how it is actually applied by a physiotherapist or someone monitoring the exercise program. It would certainly help me, and possibly others, if you could provide more information in regard to how it can be applied in a practical setting.
Additional comments: I think this study addresses an important topic. The introduction, discussion, and conclusion seem to relate to the main purpose but a lot of the other sections seem to cover a variety of tangential areas that do not seem to relate to main purpose. The main focus of the study seems to get a bit lost and I found it quite difficult to follow and keep the main thread. However, there is a lot of good content but think you  need to make it much clearer how your approach can be applied to a more practical setting which is really the main concern expressed in the introduction.


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: MONITORING THE TRAINING DOSE AND ACUTE FATIGUE RESPONSE DURING ELBOW FLEXOR RESISTANCE TRAINING USING A CUSTOM-MADE RESISTANCE BAND
Review round: 1
Reviewer: 2

Output:
Basic reporting: No comment
Experimental design: No comment
Validity of the findings: No comment
Additional comments: This is an interesting and well written article. It cites adequate and relevant references. The introduction provides an adequate background. The structure, figures and tables are also adequate. However, one major problem is that the authors speculates too much about factors that they have not controlled and for which they don’t have adequate methods, like fatigue and strength. I strongly suggest removing this from the study and concentrate in the use of procedure they present. It will be necessary to expand the discussion and keep it limited to the main purpose. See below some specific comments.

Line 138 - it might be interesting to cite that previous studies reported that resistance training with elastic bands promotes similar results to resistance training performed in traditional equipaments (machines and weights) : doi: 10.1016/j.exger.2018.12.001

Line 263 - Please provide a more detailed description of the 1RM test. It is not possible to understand it and this information is very important for your article.

Line 268 - The range of load (40-60%) is very large! This imprecise estimation can influence your results regarding fadigablity, for example. Therefore, I suggest that you remove all aspects that might be influenced by not having a precise estimation of maximum and relative load and stick with your main results, that is, the validity of your procedure to monitor training and its implications.

Line 299 - Please review this phrase and consider substituting “got tired” by a more scientifical term

Line 306 – If you want to describe the subjects characteristics I recommend to do it in more detail and in a separate session (include a “Participants” topic in your methods)

Line 318-320 – I see no use in comparing participants. This is not relevant to your study and you don’t have an adequate design for that. Your number of participants is very low, your sample is heterogenous and the force measurements are not precise. With that in mind, also remover the speculation in lines 306, 346-351, the discussion from 401-450 and the conclusion from 478-484

Line 333 – The lack of standardization for the load used is a big problem, especially because you are using normalized data. According to your description the load used could be anywhere between 40-60%, therefore, the expected slope could be completely different, since higher loads will induce greater fatigue.

Line 340-342 – you cannot state that this is due to the difference in initial force because you did not measured it adequately and the you don’t have a precise measure of the relative effort. The force exerted might not mean that they are stronger, but that they applied more effort (began at a higher % of their maximum).


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: MONITORING THE TRAINING DOSE AND ACUTE FATIGUE RESPONSE DURING ELBOW FLEXOR RESISTANCE TRAINING USING A CUSTOM-MADE RESISTANCE BAND
Review round: 2
Reviewer: 1

Output:
Basic reporting: I think the paper is well written but the paper still needs a critical read for grammatical accuracy, spelling, and tense agreement. This seems to be particularly true of parts that have been changed or added. The authors may find it easier to report what they did and found in the past tense and not the present tense.

e.g. line 134 "they promotes.."; equipament.."
       lines 273/4  "subjects were instructed to flex or extend his forearm..."

There are other parts of the manuscript that need to be corrected appreciating the fact that English is probably not the first language of the authors.
Experimental design: The study is described as a pilot study so it is really up to the journal editors to decide if they wish to publish a paper at this stage of a long term project. There are limitations due to the nature of a pilot study that the authors acknowledge.

I do feel the purpose of the study is now much clearer. The authors developed an automated system for segmenting resistance force data into contraction phase-specific
segments. Such a system could be applied to home-based resistance training programs to monitor compliance of patients. I still feel that the purpose tends to get lost a little in paper and some of the peripheral discussion.

I am still having a problem in understanding how the participants performed the exercise. Did they do it under supervised conditions or where they given the familiarization session and then instructed to perform the exercise regimen by themselves?  Or are you (the authors) just concerned at this stage in seeing if the actual monitoring system is able to detect the contraction phases and not the ability of the subjects to independently follow the prescribed directions? Maybe you feel this is clear but I have read the manuscript several times and am still having problems on this point.
Validity of the findings: I think you have shown that the system you have developed is capable of showing the distinct contraction phases of an exercise such as forearm flexion. The next step would be to apply it an older demographic.

I would suggest if you are interested in an older demographic who may be confined to a wheelchair that you also investigate the application of your system to a more functional movement such as forearm extension rather than flexion as this action would seem to have more functional significance.

I also have a slight problem in describing the forearm curl as flexion and extension but not sure what to suggest in this regard. The extension phase is the eccentric loading of the forearm flexor muscles and not performed by the forearm extensors. Perhaps just describing the contraction as the concentric and eccentric components may be more explicit.
Additional comments: I appreciate you making many of the suggested changes and/or clarifying some of the parts of your study in your rebuttal.


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: SOUND PRODUCTION IN THE MEAGRE, ARGYROSOMUS REGIUS (ASSO, 1801): INTRASPECIFIC VARIABILITY ASSOCIATED WITH SIZE, SEX AND CONTEXT
Review round: 1
Reviewer: 1

Output:
Basic reporting: ok. Basically well-written, but some language glitches pop up.
Experimental design: ok
Validity of the findings: Fine except I would delete juveniles since the fish may not be juveniles. Lots of good information in this paper.
Additional comments: Pereira et al provide an interesting study of sound production in the Meagre, Argyrosomus regius using a development trajectory to compare sounds of captive juveniles, males and females and captive fish with wild ones. The paper is basically well-written and clear despite some minor errors that should have been caught. I do have some problems with the paper but believe they can be corrected.
First problem is the use of juveniles. I could grudgingly accept the 9 cm TL fish as a juvenile even with differentiated testes but think it is unlikely to be a fair descriptor for the 30-50 cm TL fish. First the authors provide no evidence of what constitutes a juvenile either with data or references to other studies. Secondly, I don’t think the term adds much. Their ontogenetic studies stand without using the word. Therefore either substantiate that these rather large fish are in fact juveniles or delete the term. I don’t think it adds anything to the paper.
I am also uncomfortable with the frequent use of the term gender, a squishy psychological term in place of sex. After all the fish are regular males and females. I can live with the term but see it as a mistake. Check with the American Psychological Association for more about gender.
The authors use the conventional term advertisement calls in the key words but repeatedly refer to social calls in the text and figures. Social calls immediately made me look for other kinds of interactions between individuals besides male courtship calls. Why be vague when there is a traditional term for what they describe.
L 43. I don’t see Radford et al in the refs?
L 52. 1986) ), ?
L 60. Tellechea et al (2010) from the J Exp Zool should be added to the ref string on black drum, particularly since the study compared male and female calls.
L 61. Acoustic rather than acoustics?
L 86. Sciaenids are not known to produce agonistic calls. I believe disturbance or distress calls would not typically be considered agonistic.
L 88. Allowing "recognition of" not allowing to recognize or.
L 92. Data provide.
L 110-113. Awkward and unclear. Rewrite.
L 114. Delete with.
L 115. "Were" not and not corresponded to.
L 120. Hard to believe that a 50 cm sciaenid is a juvenile. Delete or provide justification.
L 131. What is a sleeve and what is it made of? We need to know this to make sure it would not affect sound transmission.
L 138. I can guess, but what is an ichthyometer. Probably not necessary to give brand names for measuring TL and weight.
L 175. Were never fluid???
L 191. Delete The data set used in this study consisted of and add a “were” before obtained.
L 193. The hydrophone model was already mentioned. Once is enough unless there were different ones.
L 207. Again social sounds made me wonder if other reactions were taking place. Please stick with advertisement calls.
L 208-210. Awkward. Rewrite definition to make pulse period clearer. Perhaps use a second sentence.
L 214. Parameters were.
L 220. You state that all the sounds in this study were analyzed in one 5 hr period. Rewrite.
L 222. Which not witch.
L228. Delete and. It makes the sentence confusing.
L 240. Data considered mean values but sometimes all sounds were plotted (see Fig. 5). I think it would be better to stick with means less someone mention the P word (pseudoreplication).
L 248 level not levels?
L 253. Call not calls.
L 267. As far as I know, testicles are found in mammals not fishes. Use testes.
L 271. Re: all acoustic features. The authors don’t describe the acoustic waveform, which appears to be made of a single major cycle in the “juvenile” (Fig. 1) and multiple cycles in adults. This should be described and we need to know if the juvenile pulse is typical. Additionally the sound from the field appears to attenuate more rapidly than in the tank suggesting some reflections or tank resonance. Not a major concern, but it should be mentioned.
L 275. Delete second pulses.
L 277. Re: Fig 4. Not clear why we are going from regressions to box plots?
L 285-296. I am not convinced that this paragraph and Fig. 5 are providing new information.
L 304-305. The degrees of freedom, which should be 8, should be provided.
L 336. Pobably?
L 348. I asked Martin Connaughton who has watched weakfish producing sounds during courtship and he witnessed jockeying for position but no agonistic sounds?
L 365. Art Myrberg’s paper was on pomacentrids not sciaenids.
L 371. Not sure fighting ability is relevant here?
L 378. Number of pulses is determined by the cns. It should not be necessary to defend advertisement calls used in courtship here.
L 386. Energy of the remaining is unclear. Rewrite.
L 415. Would mention black drum here too.
L 420. Sounds like you may be repeating information already presented in the discussion.
L 422. Sentence is unclear: Usually, size and sex are extremely correlated due to the presence of sex size dimorphism.
L 425. Hill (1950)?
L 435. Swimbladder gas pressures typically match ambient pressure so there is a slack membrane, e.g. no relation to tension. Frequency of sounds is determined by time to contract and relax or the interval between contractions.
L 458. Worth to note???? Since you have the usual sounds (disturbance and advertisement calls) why speculate on what is missing?
L 474. Populations.
Michael L. Fine


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: SOUND PRODUCTION IN THE MEAGRE, ARGYROSOMUS REGIUS (ASSO, 1801): INTRASPECIFIC VARIABILITY ASSOCIATED WITH SIZE, SEX AND CONTEXT
Review round: 1
Reviewer: 2

Output:
Basic reporting: The article has clear and unambiguous, professional English used throughout. However, some improvements could be made:
Lines 110-113. I got lost here, especially the part on juveniles. Please re-write to improve the communication of what you want to say.
Lines 114-117. If the fish were in unisex tanks, why was there a sex ratio? Unisex should mean males and female were apart in separate tanks and, therefore, there would be no sex ratio. I did not understand something here. Please improve.
Line 267. Use testes rather than testicles.

The article completed the points on: Literature references, sufficient field background/context provided. Professional article structure, figures, tables. Raw data shared. Self-contained with relevant results.
Experimental design: Methods described with sufficient detail & information to replicate. I have some questions and observations.

I had trouble to understand the “n” used in the datasets that were analysed. The number of animals used is in the text as in the number of recordings per animal, but I found it hard to understand how these two “n” values were used and what the “n” was in the actual statistical analysis, i.e. the “n” per group in the tests. The authors should make this clear in the text and put the “n” in all tables and figures. The “n” should refer to the number of animals used. The authors should consult with a statistician. I think it is not correct to use repeated measures from the same animal as different data in an ANOVA or t-test. I suggest the authors use a repeated measures ANOVA that identifies the subject of the repeated measures and the treatments, origin, sex, context etc.

Line 257, an n of 4 males and 6 females does give an n=10. It is two groups with n=4 and n=6.

With the field data how were the authors sure that the sounds were from a single animal? Is it possible that the pulses came from more than one animal?
Can the size of the fish in the field data be estimated from the correlations? This could be interesting?

Figure 3. The correlation coefficients should be included. Some of the correlations look poor.

Line 238, Indicate that it is the “P” value.

The article completed the points on: Original primary research within Aims and Scope of the journal. Research question well defined, relevant & meaningful. It is stated how research fills an identified knowledge gap. Rigorous investigation performed to a high technical & ethical standard.
Validity of the findings: Impact and novelty not assessed. Negative/inconclusive results accepted. Meaningful replication encouraged where rationale & benefit to literature is clearly stated.

All underlying data have been provided; they are robust, statistically sound, & controlled. See comments in Experimental design section.

Conclusions are well stated, linked to original research question & limited to supporting results.

Speculation is welcome, but should be identified as such.
Additional comments: I was not convinced by the discussion on sound related to spawning. I do not think it is good practice to think that any sounds made during the spawning period, which is months, were related to spawning. Can the authors justify this assumption or remove it and text discussing this assumption? I think a closer relationship is required between the sounds and spawning. I would suggest that only sounds obtained at the time of spawning should be assumed to be sounds related to spawning. For example sounds recorded just before eggs are collect from a tank.


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: SOUND PRODUCTION IN THE MEAGRE, ARGYROSOMUS REGIUS (ASSO, 1801): INTRASPECIFIC VARIABILITY ASSOCIATED WITH SIZE, SEX AND CONTEXT
Review round: 1
Reviewer: 3

Output:
Basic reporting: see pdf
Experimental design: See pdf
Validity of the findings: see pdf
Additional comments: see pdf


Instruction: You are one of the reviewers, your task is to write a review for the article. You will be given the title of the article, the number of the round in which the article is located, and your order among the reviewers.

Input:
Title: SOUND PRODUCTION IN THE MEAGRE, ARGYROSOMUS REGIUS (ASSO, 1801): INTRASPECIFIC VARIABILITY ASSOCIATED WITH SIZE, SEX AND CONTEXT
Review round: 2
Reviewer: 1

Output:
Basic reporting: Nice job.
Experimental design: Careful.
Validity of the findings: Yes.
Additional comments: I am pleased with the revisions to Peiria et al. although I still have a few minor comments.
L 44. I thought the ref to Myrberg was deleted since the sentence, at least as now written, is restricted to sciaenids, and he worked on pomacentrids.
L 74. Tellechea et al described male and female sounds in black drum and whitemouth croaker and should be mentioned here.
L 160. Posteriorly at the beginning of the sentence does not make sense.
L 224. Produced not poduced.
L 382. Naïve readers may not realize the significance of this conclusion, and I would therefore add “of a forced rather than a resonant response” after conclusion.
L 422, 446 legend for Fig. 7 and maybe other places. I thought you agreed to not use gender for sex?
L  597. Place author references starting with “R” after those starting with P.
Fig. 2 did not come though clearly in my copy.
Fig. 5. Incredibly minor, but the e in the legend for disturbance at the bottom right is partially up against the border.
Fig. 7. Male under the graphs needs to be moved to the right. I suspect the software did something unintended.