*Edit: After posting this, I learned both Andrea Cau (here) and Brad McFeeters (on Facebook) independently came to the same conclusion. Guess it really was an obvious synonymy. ;)
I'm skeptical that these and Deltadromeus belong in Tetanurae, as it only takes 4 steps to move them to Ceratosauria in Apesteguia et al.'s version of Carrano's tetanurine analysis, and Deltadromeus wasn't added to their version of Novas' tetanurine analysis which also lacks any ceratosaurs except the outgroup Ceratosaurus. They note "Gualicho does exhibit some apparent ceratosaurian synapomorphies, most notably a robust MT III with posteriorly expanded proximal articulation and a flange-like m. iliofibularis tubercle." It would have been interesting to run them in a ceratosaur analysis.
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| Holotypes of Gualicho shinyae (MPCN PV 0001; top) and Aoniraptor libertatum (MPCA-Pv 804; bottom) in posterior (E), anterior (F), left lateral (G) and dorsal (H) views. Modified from Apesteguia et al. (2016) and Motta et al. (2016). |
References- Apesteguía, Smith, Juárez Valieri and Makovicky, 2016. An unusual new theropod with a didactyl manus from the Upper Cretaceous of Patagonia, Argentina. PLoS ONE. 11(7), e0157793.
Motta, Aranciaga Rolando, Rozadilla, Agnolin, Chimento, Brisson Egli and Novas, 2016. New theropod fauna from the Upper Cretaceous (Huincul Formtation) of northwestern Patagonia, Argentina. In Khosla and Lucas (eds.). Cretaceous period: Biotic diversity and biogeography. New Mexico Museum of Natural History and Science Bulletin. 71, 231-253.
Nototyrannus violantei idem.
ReplyDeleteIf they are synonyms, I think Gualicho may become a nomen protectum; it seems to be getting used a lot more than Aoniraptor, at least as far as Google tells me; as Aoniraptor has about 2,180 results, while Gualicho has about 344,000 results.
ReplyDeleteSo technically, shouldn't Gualicho be able to be named a nomen protectum, as it seems to have a lot more recognition then Aoniraptor? Or will this devolve into a Manospondylus/Tyrannosaurus situation?
Being the cynic I am regarding the state of nomenclature these days, these kinds of thoughts certainly entered my mind. I don't think it would be fair at all to Motta et al. to make their name a nomen rejectum merely because they lack publicity. Surely that's unscientific, and would require an ICZN petition. The more likely scenario in my mind is that few workers actually acknowledge Aoniraptor, and those that do just brush it off as a nomen dubium without detailed comparison or justification.
DeleteTrue, it would require an ICZN petition. And honestly, I'm not keen on that idea, either...but it'd be best to act now so that we won't potentially end up with a similar situation to how, say, "Nanotyrannus" or Manospondylus are currently.
DeleteHonestly, either name would be fine for me; I just don't want to have to deal with a prolonged debate over which Patagonian Cretaceous megaraptoran is valid, as has happened with other dinosaurs. :p
Well, Manospondylus is seemingly a nomen oblitum (though it would be interesting to examine just how it fulfills ICZN Article 23.9). Nothing named as valid today can become a nomen oblitum because to qualify, a name must not be "used as a valid name after 1899" (ICZN 23.9.1.1). Thus for Aoniraptor, authors wishing to reject it on nomenclatural grounds would have to follow ICZN Article 23.9.3.
DeleteNanotyrannus isn't a similar issue, because that's a scientific dispute over whether one taxon is a juvenile stage of another. Everyone agrees Nanotyrannus is distinct, they just argue whether that distinction is ontogenetic or phylogenetic. The ICZN rightly has no jurisdiction over resolving science-based questions like that.
Well, I know that T.rex fufills Article 23.9.1.2, but has anybody used Manospondylus as a valid name since 1989?
DeleteIf so, then we may be at a point where we'll need to just buckle down and get this mess sorted out. That'd likely just result in Mano being surpressed, but a solution is better than ignoring it.
For Aoniraptor and Gualicho; that is the best course of operations if we really do need to synonymize those genera. I feel like the latter may take priority, seeing as how it's been recieving more publicity...but who knows? Maybe we'll keep Aoniraptor valid and ditch Gualicho.
We'll just have to wait and see...which is sometimes the worst part of being a palaeontologist. :p
Gualicho is an already extant word in South American Spanish (also spelled gualichu). That's probably inflating the results.
DeleteAnd that's why I put in "Gualicho shinyae" as my search, Pete; to avoid result inflation.
DeleteThe PDF version of the paper naming Aoniraptor does not appear to meet the requirement of ICZN Article 8.5.3 ("Works issued and distributed electronically. To be considered published, a work issued and distributed electronically must be registered in the Official Register of Zoological Nomenclature (ZooBank) (see Article 78.2.4) and contain evidence in the work itself that such registration has occurred."), while the print edition did not, as of July 13 2016, meet the requirement of Article 8.1.2 ("it must be obtainable, when first issued, free of charge or by purchase"). According to Article 21.9 ("Works issued on paper and electronically. A name or nomenclatural act published in a work issued in both print and electronic editions takes its date of publication from the edition that first fulfilled the criteria of publication of Article 8 and is not excluded by Article 9."), the print edition will establish the recognized publication date for these taxa when it becomes publicly obtainable. In an e-mail yesterday, one of the editors of the volume (S. G. Lucas) informed me that the print edition had just been shipped from the printer, and will be available for purchase in about two weeks.
ReplyDeleteGualicho appears to technically have priority over Aoniraptor, no popularity contest necessary.
Well, that solves that. Not including a ZooBank registration is just negligent these days. Hopefully Novas, Agnolin and such have learned their lesson from Aoniraptor's fate.
DeleteAlright then, from now on I guess we can safely lump "Aoniraptor" into Gualicho.
DeleteGood to see a solution so quickly, though. Will go updating WP appropriately.
Rolando et al. (2020) do not consider Aoniraptor to be the same taxon as Gualicho based on morphological differences between the tail vertebrae of the holotypes of both genera.
DeleteAranciaga Rolando, M., J. Garcia Marsà, and F. Novas. 2020. Histology and pneumaticity of Aoniraptor libertatem (Dinosauria, Theropoda), an enigmatic mid-sized megaraptoran from Patagonia. Journal of Anatomy 237: 741–756. https://doi.org/10.1111/joa.13225
Hmm... their arguments seem compelling. I'll divide them up in my next update.
DeleteIf A.libertatem is not related to G.shinyae as they argue(which seems reasonable to me),any chance this has implications for relationship with both D.agilis and B.ingens?
DeleteMotta et al.,2016 noticed some shared derived characters with the latter taxa,but D.agilis looks closer to G.shinyae than it does to A.libertatem and B.ingens,at least to me.Is there any possibility A.libertatem and B.ingens are closely related taxa but lack affinities with D.agilis and G.shinyae?
I also should mention there's a preprint("The Biggest Megaraptoridae (Theropoda: Coelurosauria) of South America") describing a new Megaraptorid from Argentina where they recovered G.shinyae as a Tyrannosauroid and A.libertatem as a Megaraptoran.There's no Ceratosaur apart from Ceratosaurus,so I doubt the position of G.shinyae in Tyrannosauroidea is well supported.
Refs:
1) Motta, Matias & Aranciaga Rolando, Alexis & Rozadilla, Sebastián & Agnolin, Federico & Chimento, Nicolas & Brissón Egli, Federico & Novas, Fernando. (2016). NEW THEROPOD FAUNA FROM THE UPPER CRETACEOUS (HUINCUL FORMATION) OF NORTHWESTERN PATAGONIA, ARGENTINA. New Mexico Museum of Natural History and Science Bulletin.
2) Rolando, Alexis & Motta, Matias & Agnolin, Federico & Manabe, Makoto & Tsuihiji, Takanobu & Novas, Fernando. (2021). The Biggest Megaraptoridae (Theropoda: Coelurosauria) of South America. 10.21203/rs.3.rs-1152394/v1.
After separating Gualicho and Aoniraptor in the Lori analysis and updating Deltadromeus based on Ibrahim et al. (2020) (and adding Berthasaura and updating Limusaurus based on Stiegler 2019, etc....)
Delete- Aoniraptor is a basal megaraptoran.
- Gualicho and Deltadromeus are basal tyrannosauroids.
- Bahariasaurus is by Scuirumimus in Compsognathidae.
So that's support for the idea Delatodromeus and Gualicho aren't close to Aoniraptor and Bahariasaurus, but I would also caution that without any explicit ceratosaur/tetanurine/avetheropod/tyrannosauroid/megaraptoran characters, the Lori matrix isn't a great test for this.
Also, thanks for the "Maip" paper link, which I was unaware of.
I really happy to hear that Gualicho have priority over Aoniraptor.
ReplyDeleteI don't particularly like the rule about electronic publication not having priority (though, not putting a ZooBank registration is sort of irresponsible, however), but I'm pretty confused about a few of those rules anyway. But it is what it is, Gualicho shinyae is a cool name at least.
ReplyDeleteNow the thing I'm really confused about is Gualicho's placement within Theropoda (and I suppose Deltadromeus and Bahariasaurus as well). Gualicho and Deltadromeus look superficially like noasaurids to me, but I'm far from an expert on anatomy or phylogeny, so that's just a gut reaction. Time will tell I hope.
After reading the paper completely, there are so many times Apesteguia et al. note ceratosaur-like characters in Gualicho, most of which weren't used in the tetanurine-centric analysis of Carrano et al.. I also added both it and Deltadromeus to the Lori analysis as a test, and neither one emerged anywhere by Neovenator or megaraptorans.
DeleteHi Mickey, what was then your result of Gualicho and Delta in the Lori analysis? closer to ceratosaurs?
DeleteThe Lori analysis is centered on coelurosaurs, and uses all of the Theropod Working Group characters, so has no characters designed to support Tetanurae, Ceratosauria, Avetheropoda, Orionides, Abelisauroidea, etc.. Gualicho and Deltadromeus emerged together in Ornithomimosauria, BUT so did Elaphrosaurus. Unlike Peters, I'm smart enough to realize this is due to character sampling. The outgroup is currently Cryolophosaurus, and I haven't included any other ceratosaurs.
DeleteI'm pretty confused about a few of those rules anyway
ReplyDeleteThat's OK. Some of them really are confused.
Example: Are types specimens or individuals? There are hints and implications, but no clear statement anywhere. Of course most specimens are all we have of exactly one individual; but some aren't.
I think I've even found Rules that outright contradict each other.
In the present case, though, there's no question: Gualicho is validly published, "Aoniraptor" is not.
Rolando, Mauro Aranciaga; Marsà, Jordi Garcia; Novas, Fernando (2020). "Histology and pneumaticity of Aoniraptor libertatem (Dinosauria, Theropoda), an enigmatic mid-sized megaraptoran from Patagonia" ?
ReplyDeleteYeah, I agree with that paper and need to update the Database to reflect it.
Delete