Tameryraptor, new carcharodontosaurid taxon from destroyed holotype from Bahariya Formation, Egypt (free pdf)

[Ben Creisler]

Ben Creisler

bcre...@gmail.com

A new paper:

Free pdf:

Tameryraptor markgrafi gen. et sp. nov.

 
Maximilian Kellermann, Elena Cuesta & Oliver W. M. Rauhut (2025)
Re-evaluation of the Bahariya Formation carcharodontosaurid (Dinosauria: Theropoda) and its implications for allosauroid phylogeny.
PLoS ONE 20(1): e0311096
doi: https://doi.org/10.1371/journal.pone.0311096
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0311096


The first partial skeleton of a carcharodontosaurid theropod was described from the Egyptian Bahariya Oasis by Ernst Stromer in 1931. Stromer referred the specimen to the species Megalosaurus saharicus, originally described on the basis of isolated teeth from slightly older rocks in Algeria, under the new genus name Carcharodontosaurus saharicus. Unfortunately, almost all of the material from the Bahariya Oasis, including the specimen of Carcharodontosaurus was destroyed during World War II. In 1996, a relatively complete carcharodontosaurid cranium was described from similar aged rocks in Morocco and designated the neotype of the species Carcharodontosaurus saharicus in 2007. However, due to the destruction of the original material, comparisons of the neotype to the Egyptian fossils have so far only been done cursorily. A detailed reexamination of the available information on the Egyptian carcharodontosaurid, including a previously undescribed photograph of the exhibited specimen, reveals that it differs from the Moroccan neotype in numerous characters, such as the development of the emargination of the antorbital fossa on the nasals, the presence of a horn-like rugosity on the nasal, the lack of a dorsoventral expansion of the lacrimal contact on the frontals, and the relative enlargement of the cerebrum. The referability of the Egyptian specimen to the Algerian M. saharicus is found to be questionable, and the neotype designation of the Moroccan material for C. saharicus is accepted here under consideration of ICZN Atricle 75, as it both compares more favorably to M. saharicus and originates from a locality closer to the type locality. A new genus and species, Tameryraptor markgrafi gen. et sp. nov, is proposed for the Egyptian taxon. The theropods of the Bahariya Oasis and the Moroccan Kem Kem Group are thus not as closely related as previously thought, and the proposed faunal similarities between these two strata need further examination.

[Mickey Mortimer]

Interestingly, the peer review indicates this was originally going to be named "Alllissaurus" ("Etymology: Alllissaurus is a combination of the arabic for marauder, اللص (Al llis) and the greek word for lizard, saurus").  Peer Reviewer 1 wisely commented "It is noteworthy that the pronounciation of this word is very similar to "Allosaurus" in several languages, and that the series of three "l" could easily be misreported in literature. I'd avoid the introduction of such name." So that's another nomen nudum for the lists.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0311096.s007&type=supplementary

Mickey Mortimer

[Thomas Richard Holtz]

An additional note: "Alllisaurus" would likely be autocorrected both in word processors and in web searches to "Allosaurus".

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[Gregory Paul]

I have long been very suspicious of how formations far across north Africa have been stated to be the same age, and inhabited by the same species. As the below shows there is no radiometrics or microfossil data showing such is true. So Spinosaurus aegypticus is limited to Egypt. Similar to how saying Dollodon is the same species as Mantellisaurus atherfieldensis when the age of the former is not well known (found in an ancient sinkhole) and is almost certainly not the same as M. a. is very unlikely to be correct. Yet those papers get through review. We need to tighten up the stratigraphic science folks. 

GSPaul

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[Tim Williams]

Mickey Mortimer <therizino...@gmail.com> wrote:

> Interestingly, the peer review indicates this was originally going to be named "Alllissaurus" ("Etymology: Alllissaurus is a combination of the
> arabic for marauder, اللص (Al llis) and the greek word for lizard, saurus").  Peer Reviewer 1 wisely commented "It is noteworthy that the
> pronounciation of this word is very similar to "Allosaurus" in several languages, and that the series of three "l" could easily be misreported in
> literature. I'd avoid the introduction of such name." So that's another nomen nudum for the lists.

An alternative remedy could have been to drop the definite article in 'Al llis' to make "Llissaurus".  But _Tameyraptor_ is a perfectly good name, incorporating an ancient name for Egypt (Tamery).  As I understand, Tamery (tȝ-mrj) would have originally been written in hieroglyphics.  

Regarding theropod phylogeny, _Shaochilong_ (formerly _Chilantaisaurus maortuensis_) is recovered here as a basal tyrannosauroid, as did Rauhut et al. (2024) in their description of _Alpkarakush_.  This makes sense, given the presence of a sagittal crest in  _Shaochilong_. 

With _Saurophaganax_ no longer regarded as a valid genus, family Allosauridae contained _Allosaurus_ as its only member.  But Kellermann et al. recover _Asfaltovenator_ as an allosaurid in most of their analyses, as well as _Yunyangosaurus_ in some.  So Allosauridae is no longer monotypic in these phylogenies.

[Jaime Headden]

The Bahariya is roughly coeval to portions of the Kem Kem supergroup to which these particular fossils were located. The Douira FM (in which the FSAC specimen of spinosaur was discovered, along with the SGM-Din 1 neotype for C. saharicus) is approximately mid-Cenomanian as aligned by various vertebrate inclusions in its strata, and generally constrained by a transgression which split paleo-Morocco from paleo-Algeria (yes, the Algeria that contains the type C. saharicus teeth, split by an epicontinental waterway), whereas the Bahariya FM might be older based on palynological and vertebrate biostratigraphy but was subjected to the same epicontinental transgressive sea level rise. So they were approximately coeval, so much so we might not worry too much about the particularities of how coeval (such as the Montana-Alberta Campanian-Maastrichtian sequence, the fine details would need far better sampling to uncover).

My only concern with this act is that there is still an issue of "as close as is practicable" when it comes to neotype designations, and transferring missing fossils to new species on account of nomenclatural niceties. If the photographs of fossils are so actionable as to play taxonomical games, then so they are for Spinosaurus aegyptiacus: that is, we don't need a neotype for it. If this is the goal of the authors, then whatever. Make that statement.

The issue still remains that there was an epicontinental sea separating the Moroccan deposits from Algerian, Tunisian, and Egyptian, and this would (probably) impact speciation and diversification. It's more likely "Tameryraptor" to be closer to C. saharicus than the neotype is, based on this alone, but really, I'm all for dumping C. saharicus as a useless taxon, and this act simply suggests it better to redesignate SGM-Din 1 to a new species (along with FSAC-KK 11888; there managed to get THAT in).

Cheers,

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Jaime A. Headden

The Bite Stuff: http://qilong.wordpress.com/

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[The Dinosaur Heretic]

I agree that an epicontinental sea would likely impact speciation and diversity, but the wording of your following statement confuses me; in what capacity would Tameryraptor be closer to C. saharicus than SGM-Din 1? The authors of the Tameryraptor paper assert that the neotype for C. saharicus is valid because both animals are treated as anatomically distinct. It’s not as if the authors argue that SGM-Din 1 be assigned to Tameryraptor and C. saharicus maintain priority of SNSB-BSPG 1922 X46. Similarly, they’re not all that close through a phylogenetic perspective, as Tameryraptor was only recovered as a carcharodontosaurine in 0-1 of 8 runs. By contrast, C. saharicus was always recovered as a carcharodontosaurine in all 8 runs. 

So are you instead suggesting that Tameryraptor is a better representative of C. saharicus than SGM-Din 1? If so, why? SGM-Din 1 has been the touchstone for C. saharicus since at least 1996, so wouldn’t assigning this specimen to a new species be detrimental to communication within the community? Alternatively, would the community at large refuse to adopt this change? To me, this hypothetical harkens to the discussion regarding the ICZN ruling that Tyrannosauridae takes priority over Deinodontidae, in that the community has been using SGM-Din 1 to refer to C. saharicus for so long that it would be controversial and ultimately useless to change the specimen’s designation. These are different situations, but the outcome, to me, would read the same.

This brings me to your point about Spinosaurus. If under the same conditions as Tameryraptor and the C. saharicus neotype, would it not then suggest that the destroyed Spinosaurus holotype be renamed and the neotype remain as community’s reference point for S. argyptiacus? Or is your approach similar to the above paragraph in regards to community use and priority?

Finally, I’m a little lost on your use of “nomenclatural niceties”. I understand the phrase, but I’m not clear on the use here in regards to Tameryraptor, C. saharicus, or Spinosaurus. If Tameryraptor is genuinely distinct from C. saharicus (especially when informed by an epicontinental sea potentially affecting diversity and speciation), would it not then be a necessity to designate these animals as separate? As such, would it no longer be a nicety then?

I’m by no means suggesting you’re wrong, I’m just hoping for clarity on your perspective.

Cheers,

Ethan Townsend

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[Jaime Headden]

> The authors of the Tameryraptor paper assert that the neotype for C. saharicus is valid because both animals are treated as anatomically distinct.

This is irrelevant. The holotype of C. saharicus is a tooth. It prompts a neotype. I am not arguing that Tameryraptor should be discarded, but that SGM-Din 1 probably also deserves a new designation (that is, shouldn't be the neotype for a taxon based on teeth). There is limited value for C. saharicus other than as a container for Carcharodontosaurid/nae, and that's not so heavily needful to require retention.

> By contrast, C. saharicus was always recovered as a carcharodontosaurine in all 8 runs. 

C. saharicus is, by definition, a member of Carcharodontosaurid/nae. If the question is whether the other taxa are, then let's follow that argument.

> So are you instead suggesting that Tameryraptor is a better representative of C. saharicus than SGM-Din 1?

No. My statement regards the fact that the authors asserted that based on proximity, the Algerian sediments were "closer" to Morocco, thus presenting a better claim to SGM-Din 1 being C. saharicus. This isn't really true: there are other factors at play, the epicontinental sea being one of them.

> Alternatively, would the community at large refuse to adopt this change? To me, this hypothetical harkens to the discussion regarding the ICZN ruling that Tyrannosauridae takes priority over Deinodontidae, in that the community has been using SGM-Din 1 to refer to C. saharicus for so long that it would be controversial and ultimately useless to change the specimen’s designation. These are different situations, but the outcome, to me, would read the same.

This is something that would have prompted a discussion and reduction in usage of neotypes for specimens as the touchstones back in 1996---which as I recall, happened. It just didn't find much weight at the time, not because the discussion fell on the side of neotype, but because few people discussed it.

> This brings me to your point about Spinosaurus. If under the same conditions as Tameryraptor and the C. saharicus neotype, would it not then suggest that the destroyed Spinosaurus holotype be renamed and the neotype remain as community’s reference point for S. argyptiacus? Or is your approach similar to the above paragraph in regards to community use and priority?

The problem with S. aegyptiacus being placed in a Moroccan taxon is largely different. There is no good or sufficient type to fall back on "close as is practicable," save perhaps some Tunisian or Algerian material. Once we reach Morocco, we come across a problem of two distinct morphotypes: quadrates, vertebrae, other cranial bits. Another two named taxa in the Moroccan sediments would need their phylogenetics resolved with FSAC-KK 11888 before a neotype should be presented: which one matches the neotype, if there's two (or more) distinct species? The authors who proposed managed this by subsuming all diversity across the continent into a single species---the same for C. saharicus, regardless of the epicontinental sea. As the question of doubt remains unresolved, the potential for unrealized diversity among spinosaurines and carcharodontosaurines raises the problem of designating any taxon in the Moroccan sediments as a neotype for a species originally recovered elsewhere. This includes C. saharicus.

> Finally, I’m a little lost on your use of “nomenclatural niceties”. I understand the phrase, but I’m not clear on the use here in regards to Tameryraptor, C. saharicus, or Spinosaurus. If Tameryraptor is genuinely distinct from C. saharicus (especially when informed by an epicontinental sea potentially affecting diversity and speciation), would it not then be a necessity to designate these animals as separate? As such, would it no longer be a nicety then?

Without resolution or a glaring taxonomic boondoggle to resolve---such as a preoccupied name---the drive to designate neotypes to retain taxa remains more or less a cosmetic fix. This is little different than if we went back to referring to most large Jurassic "carnosaurs" as Megalosaurus. Note that I have no issues with the designation of Tameryraptor markgrafi for the now-lost Egyptian material, other than to question its value for material that can't be recovered, and thus the observations of the authors to be counterchecked by newer examiners of the material. It amounts to whether photographs can be proxies for type specimens. If the use of photographs is valuable, then it follows the same argument should be used for Spinosaurus aegyptiacus, and a neotype suddenly becomes unnecessary. (I question this, to be clear. Yes, a neotype is deserving, but at this point I doubt and have argued, at length, that it shouldn't be FSAC-KK 11888.)

> I’m by no means suggesting you’re wrong, I’m just hoping for clarity on your perspective.

I hope this helps

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[The Dinosaur Heretic]

Perfect, thank you very much Jaime. This is much appreciated.

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