Dear Mr Ijouiher,
thanks for making this MS available as a Preprint.
This MS is an interesting piece of work, especially because a comprehensive review of the Bahariya fauna allows for comparisons across the faunas in Norther Africa in the Cretaeous.
Having published on Sigilmassasaurus, I have looked through the section of this MS that deals with theropods, and have found some issues. It would be great if these could be addressed toward the final submission.
As the MS does not have any line numbers, I have to refer only vaguely to paragraphs and sentences within the "Dinosauria" section of the paper.
Only one sentence of the Dinosauria section deals with Spinosaurus aegyptiacus itself. I think this section should be expanded to briefly review the material found by Stomer, and its destruction during WWII. It would be worth noting that detailled German desctricptions, alongside drawings and few photographs of the original material exists, but that new material from Morocco referred to the same taxon has been named the neotype by Ibrahim et al. (014), even if other workers disagree with this taxonomic identification and thus the validity of the neotype designation (Evers et al. 2015).
The species epithet "braviolis" is repeatedly used throughout the MS for Sigilmassasaurus. However, the correct species name is Sigilmassasaurus brevicollis (see Russel, 1996). This should be corrected.
This comment refers to this paragraph of the MS: "While Sigilmassasaurus braviolis [sic] (Russell, 1996) is usually considered a junior synonym of Spinosaurus (Evers et al. 2012; McFeeters et al. 2013; Ibrahim et al. 2014b), it now appears that S. braviolis [sic] may indeed be a valid taxa (Evers et al. 2015)"
It is incorrect that Evers et al. 2012 or McFeeters et al. 2013 consider Sigilmassasaurus a junior synonym of Spinosaurus. Evers et al. 2012 find spinosaurid affinities for Sigilmassasaurus, and McFeeters et al. 2013 interpret Sigilmassasaurus as a valid basal tetanuran taxon. Evers et al. 2015 agree with McFeeters et al. 2013 on the validity issue, but present evidence for spinosaurid affinities. Therefore, the paragraph could be changed to something like:
'While Sigilmassasaurus brevicollis (Russell, 1996) has been considered a junior synonym of Spinosaurus (Ibrahim et al. 2014b), it now appears that S. brevicollis may indeed be a valid taxon (McFeeters et al. 2013; Evers et al. 2015).'
Evers et al. 2015 are cited in several instances, but this citation is not present in the reference list. It should be included.
Correct citation is : Evers SW, Rauhut OWM, Milner AC, McFeeters B, Allain R. (2015), A reappraisal of the morphology and systematic position of the theropod dinosaur Sigilmassasaurus from the “middle” Cretaceous of Morocco. PeerJ 3:e1323; DOI 10.7717/peerj.1323
In the sentence "While accepting the argument that there are two separate spinosaurids in North Africa, Cau (2015) questions whether this material is truly distinct from Spinosaurus (in which case Sigilmassasaurus braviolis [sic] would become Spinosaurus braviolis [sic]).", Cau (2015) is cited, but this is not listed in the reference section.
In the sentence "While such a discussion is beyond the scope of this paper; all that matters herein is that there were clearly two distinct spinosaurids in this region (Russell 1996, Evers et al. 2015), irrespective of whether they are separate on a species level or genus level.", another paper could be cited, which is Hendrickx et al. 2016. These authors also accept two spinosaurids in the Cenomanian of Morocco, and present evidence from quadrate bones that is independent of the data presented by Evers et al. 2015.
Suggested citation: Hendrickx C, Mateus O, Buffetaut E (2016) Morphofunctional Analysis of the Quadrate of Spinosauridae (Dinosauria: Theropoda) and the Presence of Spinosaurus and a Second Spinosaurine Taxon in the Cenomanian of North Africa. PLoS ONE 11(1): e0144695. doi:10.1371/journal.pone.0144695
The Sigilmassasaurus section of this MS should refer to Stromer's Spinosaurus B material. It should be noted that the material of Spinosaurus B is considered to represent Spinosaurus aegyptiacus by Ibrahim et al. (2014), but that Evers et al. (2015) list a number of anatomical differences between the original material of Spinosaurus B and the material found by Ibrahim et al. (2014).
If the author has further questions about my comments, please get in touch (my contact is available through the PeerJ paper).