Talk:Pachycephalosaurus

Which Is it?

The article currently has the following statement near the end:

Diet

Scientists do not yet know what these dinosaurs ate. Having very small, ridged teeth they could not have chewed tough, fibrous plants as effectively as other dinosaurs of the same period. It is assumed that pachycephalosaurs lived on a mixed diet of leaves, seeds, fruit and insects. The sharp, serrated teeth would have been very effective for shredding plants.

I hate to find contradictions on Wikipedia as it tends to hurt the credibility, however I'm no dinosaur or dental expert. So.....can we get a ruling on if they're teeth were "not as effective" or "very effective"? Thanks.

75.59.178.61 23:55, 28 October 2007 (UTC)

I'd have to look it up, but it's not a *complete* contradiction. The teeth would not have been great for fibrous stuff, but would have cut and sliced well (think green iguanas). J. Spencer 02:21, 29 October 2007 (UTC)

As written, it is contradictory. "Having very small, ridged teeth they could not have chewed tough, fibrous plants as effectively as other dinosaurs" ... "The sharp, serrated teeth would have been very effective for shredding plants." You can't shred plant matter effectively with small ridged teeth that don't effectively chew tough, fibrous plants. Firsfron of Ronchester 03:37, 29 October 2007 (UTC)

Shredding is not the same as chewing, which grinds food. You can't grind food very well with little triangular thingies, but you can cut it. J. Spencer 13:37, 29 October 2007 (UTC)

I totaly agree, because of the shape of its teeth.--Dinonerd4488 (talk) 19:41, 13 February 2010 (UTC)

Dead link

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

• http://www.jpinstitute.com/dinopedia/images/dc_card_pachy3_big.jpg
  • In Pachycephalosaurus on Mon Jul 17 14:50:07 2006, Socket Error: (110, 'Connection timed out')
  • In Pachycephalosaurus on Thu Jul 27 00:38:26 2006, Socket Error: (110, 'Connection timed out')

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maru (talk) contribs 04:38, 27 July 2006 (UTC)

Status of Tylosteus

Sullivan (2006) demonstrated that Tylosteus ornatus Leidy, 1872 is not referrable to Pachycephalosaurus wyomingensis and is very similar to Dracorex hogwartsia. Therefore, the ICZN will be asked to resurrect Tylosteus from the list of nomina oblita and nomina rejecta.

Sullivan, R.M., 2006. A taxonomic review of the Pachycephalosauridae (Dinosauria: Ornithischia). New Mexico Museum of Natural History and Science Bulletin 35: 347-365. 72.194.116.63 16:51, 15 April 2007 (UTC) Vahe Demirjian 09.51 15 April 2007

Synonyms in taxobox

This may be largely semantic, but the use of specific synonyms in the taxobox for a genus-level article doesn't jibe with the way we've been doing it everywhere else. I think the logic here is that on the Pachycephalosaurus, only synonyms at the genus level should be listed. If the article were titled Pachycephalosaurus wyomingensis (with the appropriate species-level taxobox that uses binomial fields instead of species subdivisions), the specific synonyms would be included. In other articles where a type or other species have synonyms, this is only discussed in the classification section. Dinoguy2 08:04, 15 November 2007 (UTC)

ok. I just figured since the genus was monotypic, the article was just as much about P. wyomingensis as it was about Pachycephalosaurus, so the synonyms belonged in the taxobox. Of course, you're right: we haven't been doing that for any of the others, and obviously there's a problem with stating that a species is synonymous with a genus. I'll revert self. BTW, since you're here, other ideas for improvement on this article are welcome... Firsfron of Ronchester 09:33, 15 November 2007 (UTC)

Pachycephalosaurus new collaboration for dec 07 with 5 votes

Nominated 16th May, 2007;

Support:

1. Cas Liber | talk | contribs 02:18, 16 May 2007 (UTC)
2. M&NCenarius 08:58, 30 May 2007 (UTC)
3. ArthurWeasley 20:38, 10 July 2007 (UTC)
4. Qwo 00:16, 20 August 2007 (UTC)
5. Firsfron of Ronchester 22:15, 18 November 2007 (UTC)

Comments:

• With this I have tried to nominate another unrepresented group, so to give people an idea of what we haven't done yet. cheers, Cas Liber | talk | contribs 02:18, 16 May 2007 (UTC)
• Surely, there are many things to say about Pachy. ArthurWeasley 20:38, 10 July 2007 (UTC)
• I've expanded and added images to practically every pachycephalosaurid article, but there is certainly a great amount of work remaining to be done. Help would be much appreciated. Qwo 00:15, 20 August 2007 (UTC)

---

GA

I've done a few dino articles, so I think I'll take a look at this. I gave it a cleanup while I was reading it. I don't think that this is the best dinosaur GA put up by the dedicated Dino group, and I think that it warrants a few fixes before attaining GA status.

• Maybe I'm being too much of a traditionalist, but I don't see the paleoecology section that pretty much every other dino article seems to have. I think it would be best to include one, but it's not a big problem.
• The skull ramming section is lacking citations. I think it would also be best to mention the headbutting in the lead as well, since it's an aspect that holds the general public's imagination.
• In the description section, who says that the dinosaur might have had long legs, short forelimbs, and ossified tendons?
• Please cite "more related to ceratopsians than ornithopods".
• Are there any depictions in popular culture of Pachycephalosaurus, seeing as they are the most well-known species in their clade.

Overall, I think that a few expansions and citations are needed to get this up to GA status. Therefore, I'm placing this on hold for now. bibliomaniac15 00:14, 10 June 2008 (UTC)

Thanks so much for the review and copyedit, Bibliomaniac. I am receptive to your suggestions and ideas, and am absolutely thrilled to be working with you again. :) Thanks so much for picking up the dinosaur review flag.

The popular culture section of this article was jettisoned at one point in 2007 because it was so anemic; I can scrape something together if you'd like. Of our GAs, Amphicoelias, Ankylosaurus, Abelisauridae, Dromaeosauridae, Gryposaurus, Heterodontosauridae, Scelidosaurus, and Tyrannosauroidea have no paleoecology section. The rest of the GAs do. A few, like Othnielosaurus have a combined paleobiology and paleoecology section.

I will add the appropriate citations tonight. The head-butting bit is in Carpenter at least, so that's an easy reference to add in. Firsfron of Ronchester 03:05, 10 June 2008 (UTC)

Right, I've done a bit of work, based on your observations, Bibliomaniac. I will continue to work on this tomorrow afternoon. Firsfron of Ronchester 07:14, 10 June 2008 (UTC)

Seems better. If the popular culture was removed before, then it's all right, no need to add it. The Paleoecology stuff isn't really needed anyway. The citations look good, and although I'd still like to see where the "ossified tendons" came from, I see nothing keeping it from GA anymore. bibliomaniac15 00:45, 11 June 2008 (UTC)

Only notable cultural reference to Pachy I can think of is the appearance in The Lost World: Jurassic Park. FunkMonk (talk) 02:17, 11 June 2008 (UTC)

Thanks for the check-back, Bibliomaniac. We sure appreciate your diligence. I know that you passed the article, but I did add a bit more to the lead, added the tendon ref, and am certainly willing to add whatever else is required/desired. A pop culture section could be made. I usually take a look at what links here to see what appearances might be suitable. In this case, it's (as FunkMonk indicates) mostly movie appearances, probably where Pachy appears in the background of a scene. Some asteroids are named after popular dinosaurs, but Pachy isn't one of them. I'm definitely open to further suggestions, however, and we could certainly start a pop culture section. Firsfron of Ronchester 02:31, 11 June 2008 (UTC)

The Pachy Zord in Power Rangers Dino Charge.65.255.88.233 (talk) 23:24, 8 May 2017 (UTC)

Is this Pachycephalosaurus?

The description of this image says "Sketch of a pachycephalosaur of uncertain systematical position and still (2003) not formally described. Its remains were found in the "Sandy Quarry" of the Hell Creek Formation, near Buffalo, South Dakota (USA). Initially reconstructed as Pachycephalosaurus wyomingensis by Michael Triebold later many attendees of an international symposium referred the remains to Stygimoloch spinifer because of the prominent spikes on the back of the skull. ". Has it been clarified what it is in the meantime? FunkMonk (talk) 07:29, 10 June 2008 (UTC)

If that is "Sandy", it is Stygimoloch (which may or may not turn out to be a juvenile Pachycephalosaurus). Perhaps a section dedicated to the "Sandy" skeleton is in order? Firsfron of Ronchester 07:45, 10 June 2008 (UTC)

Could perhaps be mentioned if it is notable? That drawing is the basis of this scale diagram, by the way, so maybe Dinoguy knows: And this skeleton for example, seems very similar to the drawing, with the spikes and stuff: FunkMonk (talk) 02:14, 11 June 2008 (UTC)

The "Sandy" skeleton is certainly notable, as a partially complete skeleton of a pachycephalosaur. I'm not sure if it belongs in this article or in Stygimoloch. Perhaps mention could be made in both. Firsfron of Ronchester 02:50, 11 June 2008 (UTC)

The drawing is Sandy. I didn't know it had been published and referred to a genus though. The scale is based on the drawing but scaled to larger pachy specimens, so it can stay here if the drawing moves. Dinoguy2 (talk) 12:54, 11 June 2008 (UTC)

Pachycephalosaurus = Stygimoloch = Dracorex

Recently Horner found Stygimoloch and Dracorex being junior synonyms of Pachycephalosaurus Please, read this http://www.sciencedaily.com/releases/2009/10/091031002314.htm This is the scientific paper http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0007626 This thing finally came out, i REALLY suggest of merging Stygymoloch and Dracorex articles in Pachycephalosaurus article —Preceding unsigned comment added by 93.33.240.155 (talk) 11:03, 5 December 2009 (UTC)

• It's already mentioned in all the affected articles. Not all scientists agree with the conclusion, so the articles should remain separate. FunkMonk (talk) 11:14, 5 December 2009 (UTC)

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Stygimoloch and Dracorex: Junior synonymy

For some reason it seems to be kind of grey here, but Stygimoloch and Dracorex are recognized as junior synonyms of P. wyomingensis in the literature now. Every recent study since 2009 (at least 5 that I know of) concerning their status has supported their placement in P. wyomingensis, and no rebuttals of papers to the contrary have been published (to my knowledge, at least non ethat I can find or are found here). The Paleobiology Database does not recognize them as valid species, and that, coupled with the fact that studies have supported their synonymy for almost a decade without rebuttal seems reason enough to sink Dracorex and Stygimoloch on Wikipedia.

There's also the fact that keeping the Wikipedia articles for Stygimoloch and Dracorex up is spreading misinformation, and is probably the reason that Stygimoloch got a part in Jurassic World: Fallen Kingdom this year. If paleontology recognizes them as invalid, but they are presented as potentially valid here, then these pages are supporting misinformation. For people having seen JW: Fallen Kingdom to search for Stygimoloch and find it has a page and a description is only going to worsen the problem.

For reference: Studies showing synonymy between Dracorex, Stygimoloch, and Pachycephalosaurus

Extreme cranial ontogeny in the Upper Cretaceous dinosaur Pachycephalosaurus http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0007626

Early Ontogeny of Pachycephalosaurine Squamosals as Revealed by Juvenile Specimens from the Hell Creek Formation, Eastern Montana https://www.jstor.org/stable/pdf/20491090.pdf?casa_token=YjatvQe2YagAAAAA:59h470ShUetdvAXGKETffEZdD6v-98Y4RHx9d9oq0Oghjv4XQtI6C8YziigNHz9UIGghvHQacP-4vrStW2qAVa6ORiybnYWchuSrDqGL9Pbozqxbbw

Texacephale langstoni, a new genus of pachycephalosaurid (Dinosauria: Ornithischia) from the upper Campanian Aguja Formation, southern Texas, USA https://s3.amazonaws.com/academia.edu.documents/30223488/longrich-sankey-texacephale-10.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1529022336&Signature=YQuqNcQENks8TVaOmRwUPMTASeU%3D&response-content-disposition=inline%3B%20filename%3Di_Texacephale_langstoni_i_a_new_genus_o.pdf

Squamosal Ontogeny and Variation in the Pachycephalosaurian Dinosaur Stegoceras validum Lambe, 1902, from the Dinosaur Park Formation, Alberta https://www.jstor.org/stable/23251281?casa_token=Vzmf2etZIRwAAAAA:CnigYjWZeyoUkgs3UHL2p1PhgUfgXfRYQ88NVA_K6EulrZt7DqfuPmX3XvJOfSDElOAWlg5xyNX76Qhs4S_03OVguu4bkRPQ67bYDcfT5SRaIsXzGQ

The early expression of squamosal horns and parietal ornamentation confirmed by new end-stage juvenile Pachycephalosaurus fossils from the Upper Cretaceous Hell Creek Formation, Montana https://www.tandfonline.com/doi/abs/10.1080/02724634.2016.1078343

• I think that might be premature. One 2015 paper, for example, only says "A third species, Stygimoloch spinifer Galton and Sues 1983, may (Horner and Goodwin, 2009) or may not be an ontogimorph of P. wyomingensis (eg, Longrich et al., 2010)." So it still depends on who you ask, there is no overall consensus. As for Jurassic World, I think a more important factor is that Stygimoloch is featured in a lot of popular dinosaur books from the 90s, and the JP franchise seems to be stuck in that era, caring little for scientific developments since. I was surprised they featured as recently named an animal as Sinoceratops, but that was probably just to pander to the Chinese market, and even that dinosaur was horribly disfigured, with open holes in the neck frill... But one strange caveat to this is that Jack Horner, who is the main proponent of the synonymy, is also the main scientific advisor to the JP series, so something doesn't add up... FunkMonk (talk) 23:41, 14 June 2018 (UTC)

• There are a few papers that mention Stygimoloch or Dracorex as possibly valid, but these are all in passing, and none are intended as actual remarks on the species status. The paper you shared demonstrates this very well; the second author, David Evans, a year later coauthored "The early expression of squamosal horns and parietal ornamentation confirmed by new end-stage juvenile Pachycephalosaurus fossils from the Upper Cretaceous Hell Creek Formation, Montana", which presented new material supporting the synonymy. Papers mentioning the genus in passing is not evidence to contradict the studies that analyze the genus' validity. As for JW, Jack Horner apparently got one veto for Fallen Kingdom. He tried to use it for Stygimoloch, but someone high up had their mind made up, so it stayed. Everyone gives him crap for the movies, but the reality is they don't listen to him. He keeps it up because it funds his lab, which is a pretty worthy cause. Among other things, it's the reason Mary Shweitzer's work on biomolecules started, and why they have such great funding to keep it up. BoneSharpe (talk) 01:33, 15 June 2018 (UTC)

I think we would need some more opinions before merging, it could be brought up at the dinosaur project talk page. But my hunch is we need to give it more time to settle. FunkMonk (talk) 14:15, 29 June 2018 (UTC)

Premature lumping

Don’t you think you’re jumping the gun a bit by lumping ‘’Stygimoloch’’ under ‘’Pachycephalosaurus’’? I mean, they don’t even belong to the same strata. ‘’Stygimoloch’’ is more recent than ‘’Pachycephalosaurus’’ — Preceding unsigned comment added by 114.75.110.242 (talk) 05:22, 1 February 2020 (UTC)

• I completely agree with this for a different reason. Until it is definitively found that Dracorex and Stygimoloch are indeed just Pachycephalosaurus, then they should remain unlumped pages, simple as that. If they do get lumped, go ahead and lump them, if they don't then they'll just remain their seperate pages, but until then they are dubious and should remain as seperate pages imo. Theferretman21 (talk) 09:18, 9 February 2020 (UTC)theferretman21

Well, since no scientific papers have contested this synonymy, the issue does not seem to be contentious. Anyhow, here is the discussion that lead to the merger: FunkMonk (talk) 22:01, 9 February 2020 (UTC)

How definite is definite for you? As the previous discussion concluded, the weight of the current scientific consensus on this matter - an uncontroversial one - is that they are ontogenetic synonyms. We are not beholden to some hypothetical future paper that might argue for their separation. If and when such a paper is published, then we can reevaluate whether we should keep them merged. Lythronaxargestes (talk | contribs) 23:25, 9 February 2020 (UTC)

But that doesn't feel consistent. People think Torosaurus is an adult Triceratops but we have them as separate. Nobody thinks that Troodon and Titanosaurus exist anymore yet they still have articles. Care to explain? 92.30.80.61 (talk) 20:25, 26 November 2020 (UTC)

It doesn't have to be consistent here, all that matters is what most of the scientific papers say. No one argues against Stygimoloch being a junior synonym, but there are still two camps in regard to Torosaurus/Triceratops. Troodon is an entirely different kind of issue. Troodon "exists", the type specimen just doesn't have any distinguishing features, so we can't assign other specimens to the genus. Same for Titanosaurus. FunkMonk (talk) 20:28, 26 November 2020 (UTC)

OK, but just remember, everyone said that Apatosaurus and Brontosaurus were the same animal and look what happened there. I'm no saying the papers were wrong, I'm just recommending the err of caution. 92.30.80.61 (talk) 19:55, 29 November 2020 (UTC)

That was a very different case, everyone agreed they were different species, just not whether they were different genera (which is subjective anyway). In this case, it's about whether these things belong to the same species or not. And no one has really argued for them being distinct in the literature recently. FunkMonk (talk) 20:07, 29 November 2020 (UTC)

Are there Pachycephalosaurus skeletons yet?

It seems there are many. But the article only discusses about the skulls.  Dinosaur (talk) 🌴🦕🦖 -- 18:15, 22 May 2020 (UTC)

There is at least one, the "Sandy" specimen, and most/all of those are replicas of that. But it hasn't been described yet, so we can't write much about it. FunkMonk (talk) 18:16, 22 May 2020 (UTC)

@FunkMonk I've been trying to find a source for this. Could you please help? So far I haven't been able to find any articles about the Sandy specimen when searching Paleobiodb with keyword Pachycephalosaurus. I understand it hasn't been described yet but it had to be mentioned somewhere else informally, didn't it?  Dinosaur (talk) 🌴🦕🦖 -- 22:38, 27 May 2020 (UTC)

Here is the product page from the sellers of the cast: http://trieboldpaleontology.com/pachycephalosaurus.html FunkMonk (talk) 22:44, 27 May 2020 (UTC)

The original fossil: http://dinosaursanctuary.com/pachycephalosaurus.html FunkMonk (talk) 22:45, 27 May 2020 (UTC)

How is P. wyomingensis the only valid species?

How can P. wyomingensis be the only valid species of Pachycephalosaurus if remains of the genus have been found in south dakota, montana and canada? P. wyomingensis was only from wyoming, hence its name — Preceding unsigned comment added by 98.18.210.108 (talk) 20:14, 4 April 2021 (UTC)

The name doesn't matter here, most studies synonymize Stygimoloch spinifer with Pachycephalosaurus wyomingensis, the combination Pachycephalosaurus spinifer has never been used in the literature, if you can provide a reference citing this combination, it'll be very welcomed. JurassicClassic767 (talk | contribs) 20:23, 4 April 2021 (UTC)

Pachycephalosaurus only lived in Wyoming?

If the only species of Pachycephalosaurus is P. wyomingensis, that means that Pachycephalosaurus only lived in the state of wyoming and nowhere else — Preceding unsigned comment added by 98.18.210.108 (talk) 20:30, 4 April 2021 (UTC)

Please read my answer in the previous comment section, the name doesn't matter. Also, the Hell Creek Formation, one of the formations were Pachy was found, isn't only in Wyoming, but also in other states. JurassicClassic767 (talk | contribs) 20:33, 4 April 2021 (UTC)

P. wyomingensis name literally says that it was found only in Wyoming, not in other states like Montana or South Dakota. — Preceding unsigned comment added by 98.18.210.108 (talk) 20:36, 4 April 2021 (UTC)

Yes, but as mentioned before, Stygimoloch, as well as Dracorex, have been synonymized with Pachycephalosaurus, and they weren't only discovered in Wyoming. JurassicClassic767 (talk | contribs) 20:44, 4 April 2021 (UTC)

But that makes no sense, and makes the species name of P. wyomingensis extremely misleading— Preceding unsigned comment added by 98.18.210.108 (talk • contribs) 98.18.210.108 (UTC)

Generally speaking, specific names referring to a place usually refers to EITHER where the holotype specimen was found, OR where the species is generally located. Sometimes both.--Mr Fink (talk) 01:52, 5 April 2021 (UTC)

Yeah, a place-name in the binomial doesn't mean it has to be exclusively found there, just that it was first found there. FunkMonk (talk) 15:53, 6 April 2021 (UTC)

Did Pachycephalosaurus have massive spikes?

If Stygimoloch and Dracorex, which are juvenile Pachycephalosaurus, had long spikes coming out of their heads, then obviously Pachycephalosaurus had to have even longer and more impressive spikes as an adult.

The spikes around Triceratops frills also appear to have been reabsorbed into the frills with age. FunkMonk (talk) 15:54, 6 April 2021 (UTC)

Why would the spikes reabsorb with age? doesn't that defeat the purpose of having spikes coming out of the head if the vanish upon sexual maturity?

Who knows (you'd have to look up the literature), depends on what exactly the spikes were for, but I don't see anyone doubting this happened in Triceratops either. FunkMonk (talk) 19:29, 30 April 2021 (UTC)

Edit request: Add information from Stygimoloch and Dracorex pages.

A few days, I saw a thread on the Dinosaurs subreddit about a person who was disappointed that the Dracorex page was redirected. (@Ornithopsis: should know what I'm talking about) This made me realize that while this page comprehensively lists most of the information on P. wyomingensis itself, it lacks information about its famous junior synonyms Stygimoloch and Dracorex. If anyone has time, someone should probably add the discovery history of Stygimoloch and Dracorex from their original pages, and maybe add how they became intertwined with Pachycephalosaurus over the years. (Think of how we added information from Othnielia and Othnielosaurus to the Nanosaurus page when all were synonymized) Thanks in advance. Miracusaurs (talk) 03:38, 8 July 2021 (UTC)

It is true that the information from the individual pages should have been transferred during the merge. Anyone can do it by looking at the old versions of the respective pages and copying the text here. FunkMonk (talk) 07:44, 8 July 2021 (UTC)

Type Species: Troodon or Pachycephalosaurus?

Why is the type species listed as Troodon and why are edits that change it to Pachycephalosaurus being reverted? Could we settle this dispute here and decide which it should be? Big baboon 272 (talk) 11:03, 18 October 2021 (UTC)

I know this comment is well over a year old, but seeing as this is a persistent issue I figure it should be clarified in writing. Over on the template page for the automatic taxobox, the parameters for the type species are very explicit about following the ICZN's guidelines, namely 67B:

The name of a type species should be cited by its original binomen. If the name of the type species is, or is currently treated as, an invalid name, authors may also cite its valid synonym.

The original binomen in this case being Troodon wyomingensis Gilmore, 1931, as the genus Pachycephalosaurus Brown & Schlaikjer, 1943 was erected from this species to form the new combination Pachycephalosaurus wyomingensis. As for the latter part, the taxobox also satisfies this condition by listing the valid combination under the species list as P. wyomingensis (Gilmore, 1931)—the brackets denoting that this is not the original combination. This is all in accordance with the ICZN's guidelines and the policy outlined by the taxobox template, and so Troodon wyomingensis Gilmore 1931 is the correct combination for the type species parameter.

Cheers, DrawingDinosaurs (talk | contribs) 05:11, 6 January 2023 (UTC)

He said, like he knew what he was talking about... Sorry, but I misunderstood what this section of the code meant when I wrote this. Troodon wyomingensis Gilmore, 1931 is indeed the original combination for Pachycephalosaurus wyomingensis (Gilmore, 1931), but it is not the species that the genus Pachycephalosaurus itself was erected upon and so not the type species. That goes to P. grangeri Brown & Schlaikjer, 1943, and is therefore the actual original combination of the type species for Pachycephalosaurus and so should be cited as such. That's my bad, I got caught up in the Troodon vs. Pachycephalosaurus part and missed the actual meaning of the code.DrawingDinosaurs (talk | contribs) 04:23, 9 April 2024 (UTC)

Evidence for Pachycephalosaurus being 70 million years old?

The taxobox states that the oldest Pachycephalosaurus is about 70 mya. Is it true as far as I know it was restricted to digsites dating 68-66mya. 61.69.150.4 (talk) 08:31, 13 January 2024 (UTC)

Stygimoloch

Maybe a bit early, but might be worth keeping an eye on https://www.idunn.no/doi/10.18261/let.57.4.7 suggesting Stygimoloch's back to being its own thing. Obviously more stuff needs to be done on papers, as I know P. spinifer remains a popular opinion on what's going on with the Stygi morph ones as well, but should we look at bringing back Stygimoloch to a separate article? Mecheon (talk) 00:24, 6 February 2025 (UTC)

This is a topic that probably won't be settled just yet so I don't think we need to make an immediate change. I would say that if another paper comes out, specifically on Pachycephalosaurus and Stygimoloch, that considers them separate, that would be enough to split the articles. For now there's really only this new study, and phylogenetic studies that don't really discuss their choices or show differences much. IJReid ^{{{T - C - D - R}}} 01:12, 6 February 2025 (UTC)

Isn’t there already 2 papers that find them separate? Sauropsid113 (talk) 23:52, 19 March 2026 (UTC)

• Makes me wonder, if this gets accepted, where does that leave Dracorex? Since flat heads are now considered a juvenile trait, it should be a juvenile of one of them, but which? FunkMonk (talk) 20:17, 20 August 2025 (UTC)

  Not necessarily. Homalocephale has been found to be valid despite being a flat headed species. Sauropsid113 (talk) 23:52, 19 March 2026 (UTC)

It may still be a juvenile even if it's distinct from Prenocephale. FunkMonk (talk) 00:31, 20 March 2026 (UTC)

Should I do a page for Stygimoloch as its separate genus/Pachycephalosaurus spinifer explaining more of the genus's history, why it was distinct genus and why it might not be anymore, or is this not that worth it? Irritatorchallengeri313 (talk) 16:09, 2 April 2026 (UTC)

We wait until a paper formally splits them. FunkMonk (talk) 19:09, 2 April 2026 (UTC)

Then how about a species page? Irritatorchallengeri313 (talk) 23:15, 2 April 2026 (UTC)

We generally avoid those for dinosaurs and other prehistoric taxa. Anyhow, there is no reason to jump the gun before some solid scientific papers have been published. FunkMonk (talk) 05:06, 3 April 2026 (UTC)

So that's why only Edmontosaurus, Pteranodon and Camarasaurus have separate species pages then. Irritatorchallengeri313 (talk) 17:12, 3 April 2026 (UTC)

Pachycephalosaurus wyomingensis is supposed to be a type species

It is supposed to be the type species not Pachycephalosaurus grangeri 2601:246:5B83:89D0:55C7:7069:F189:6185 (talk) 12:39, 8 June 2025 (UTC)

What's weird is the new type species of both Diplodocus and Iguanodon are nomina dubia, but Diplodocus didn't change its type species but Iguanodon did. Maybe it just happens. Irritatorchallengeri313 (talk) 16:03, 2 April 2026 (UTC)

The type species, regardless of whether it became a synonym of the separate, earlier named species of the same genus, is fixed by how it was originally named in the paper that described the taxon, and Pachycephalosaurus grangeri was the case. As for the instances of type species being a nomen dubium, researchers can petition to ICZN and get approval to place a separate species of the same genus as the type species, which worked for Iguanodon and Stegosaurus, but not for Diplodocus since the ICZN Opinion 2425 for Case 4700 declined the petition to replace D. longus with D. carnegii as the type species. Junsik1223 (talk) 18:26, 3 April 2026 (UTC)

Ok then; it doesn't just "maybe it just happens". Thank you for also explaining to me. Irritatorchallengeri313 (talk) 18:43, 3 April 2026 (UTC)

Etymology of Pachycephalosaurus

The correct etymology is published in a source I can not currently access, see first hit in this Google Books search. Other etymologies with kephalon are actually incorrect, as the ancient Greek word for head is κεφαλή, and not something like κεφαλών. Wimpus (talk) 19:04, 8 July 2026 (UTC)

There are also several other sources (see this Google Books search) that got this etymology (partially) correct, but those sources are also weak with respect to etymology in general as they are not written by experts that have some understanding of Greek and Latin. Wimpus (talk) 19:19, 8 July 2026 (UTC)

Our usual go-to source is , if it helps. --Jens Lallensack (talk) 19:58, 8 July 2026 (UTC)

Thank you for the link. In certain aspects it seems even better than some published sources, but unfortunately it isn't a standard published source. And in some instances, this lists also contains mistakes, like "Gr. penta "five"", while ancient Greek πεντα- (with hyphen) is the combining form and Greek πέντε is the single word for 'five', or "Gr. Akhilles", while 'Achilles' is the Latin form and Ἀχιλλεύς the Greek form, or "(Gr. barys "heavy + Gr. sauros "lizard")" for 'Barosaurus' where the noun βάρος (weight) seems a better candidate, as βαρύς has usually 'bary-' as combining form. Wimpus (talk) 21:27, 8 July 2026 (UTC)

It's by Ben Creisler, who published papers on that very subject (dinosaur etymologies), and we use that source in various FAs without problem. Anyways, do we really have to remove the entire etymology; at least the translation ("thick-headed lizard") is uncontroversial, no? --Jens Lallensack (talk) 04:08, 9 July 2026 (UTC)

'Thick-headed lizard' wasn't actually in the source on p. 152. It stated: 'Pachycephalosaurus (pak-e-SEF-alo-sawr-us. From Greek, pachys —"thickness" + kephalon— “head” + sauros—"lizard.").' I saw that Creisler published an article on etymology, but a mailing list isn't a formally published (re)source. Wimpus (talk) 07:10, 9 July 2026 (UTC)

I was of course referring to papers such as this one, not mailing list entries. We need the "thick-headed lizard" back in any case. --Jens Lallensack (talk) 12:16, 9 July 2026 (UTC)

In case you have a reliable source, be my guest. I am actually surprised that sources that use 'thick-headed lizard' in combination with the correct etymology are scarce (see here), with the second hit even mixing-up 'pachys' with 'pachos'. Wimpus (talk) 05:38, 10 July 2026 (UTC)

As I said above, the Creisler source is accepted as a reliable source here, and is widely used in articles, including FAs. And there is no reason to remove that etymology entirely, as you did. --Jens Lallensack (talk) 05:46, 10 July 2026 (UTC)

The remaining etymology was actually unsourced. Please remember that the Creisler source isn't an officially published source. Wimpus (talk) 05:56, 10 July 2026 (UTC)

Not sure what an "officially published source" is, perhaps you are referring to self-published sources. Self-published expert sources may be considered reliable per WP:RSSELF, and deprecating Creisler as a reliable source (overriding the current consensus) would affect many dinosaur articles and would require a broader discussion involving relevant wiki projects. And I'm not actually complaining that you removed an unsourced etymology, but the part "thick-headed lizard", for which there are plenty of sources to choose from. --Jens Lallensack (talk) 06:17, 10 July 2026 (UTC)

In case there are plenty of reliable (!) sources to choose from, you van add that piece of information with the appropriate reliable source. Could you please refer to the discussion of Creisler as a reliable source? Thank you. Wimpus (talk) 06:21, 10 July 2026 (UTC)

I don't remember a specific discussion. However, I cited the relevant policy that covers this source. Can you please make a policy-based argument why, in your opinion, this widely-used source (again, as said, it survived multiple successful featured article nominations where such sources are routinely questioned) is unreliable? If not, I'm going to put the complete Creisler etymology into the article. Thanks. --Jens Lallensack (talk) 07:02, 10 July 2026 (UTC)

Here is a relatively recent discussion about the Creisler website as a reliable source: (see the "Image and source review"). Does that finally convince you? --Jens Lallensack (talk) 08:18, 10 July 2026 (UTC)

Maybe I am too strict. As I said before: 'In certain aspects it seems even better than some published sources, but ... this list also contains mistakes'. So, it seems advisble to check whether the etymological content is correct when added. Etymological information from the list like '(Gr. kreos "flesh" + Gr. sauros "lizard")', 'Tomodon ... (Gr. tomo "cut" + Gr. odon "tooth")' or 'Metriacanthosaurus ... (Gr. metrikos "moderate" + Gr. akantha "spine" + Gr. sauros "lizard")' raises a few eyebrows. Wimpus (talk) 16:47, 10 July 2026 (UTC)

We don't have to be stricter than the Wikipedia guidelines and precedents set at FAC reviews determine. See WP:verifiability not truth. FunkMonk (talk) 17:15, 10 July 2026 (UTC)

If one actually checks the etymology of Creosaurus, one can find a correct etymology in Nomenclator Zoologicus. I have therefore corrected the mistake of Creisler. And the same etymology seems to be included im Marsh' own collected papers (see the first link, that I can unfortunately not access). Wimpus (talk) 18:33, 10 July 2026 (UTC)

Because the correct Greek is "kréas" and not "kreos"? Marsh didn't provide any etymologies; they had to be interpreted (and sometimes just guessed) by people like Creisler. I have no idea what this "Collected Papers" are; if they are from 1861 as stated in your link, that's almost 20 years before Creosaurus was even named. Maybe Google made something up there. --Jens Lallensack (talk) 19:35, 10 July 2026 (UTC)

I've found another link to this Google Books scanned copy. The date of 1861 seems to be a Google Book error. When browsing through this book, it seems to be a potpourri of articles of Marsh and pages with bibliographic information that might be added later by the compiler of this 'Collected papers'. Similarly that specific page with etymological information might also be an addition of the compiler. For this specific compound, it has the same etymology as the Nomenclator Zoologicus. I have not checked whether the other etymologies correspond to the Nomenclator Zoologicus.

In case one presents an etymology like '(Gr. kreos "flesh" + Gr. sauros "lizard")', one would expect that the nominative case is presented for each single word. If one asks what the ancient Greek word for 'meat' is, the expected answer would be the nominative case κρέας (kréas), i.e. 'meat' and not the (Attic) genitive case κρέως (kréōs), that actually means 'of meat'. In case I would ask you for the word 'human (being)' in German, you would answer '(der) Mensch' (nominative case) and not '(des) Menschen' (genitive case).

Creisler presents in his etymology of Creosaurus the genitive case 'kreos' and the nominative case 'sauros'. The genitive case is very often presented in classical dictionaries, but only in addition to the nominative case. The stem in Greek can be obscured in the nominative case, but can be present in another case, like the genitive. Ἄτλας (Átlas) for example has stem Ἀτλαντ- (Átlant-), but -nt- is obscured in the nominative case Ἄτλας (Átlas), while being present in the genitive case Ἄτλαντος (Átlantos). See for example Liddell and Scott and a few other dictionaries. When only one case is presented in classical dictionaries, by default it is the nominative case. Therfore, if one reads 'Gr. kreos "flesh"' one would automatically think that this would be the nominative case.

In certain instances, the actual building block is the full genitive case. In Myositis the first part myos- is the genitive case μυός (muós), that is fully incorporated within the compound with its full genitive ending -ος (-os). Greek μυοσωτίς (muosōtis) is attested as a single word but is also attested as phrase of two seperate words: μυὸς ὦτα (muòs ōta = ears of the mouse), which serves as a syntactic structure. Aquaeductus is a comparable example from Latin, that can also be written as aquae ductus or ductus aquae.

If this compound would be constructed with the actual stem (with disappearance of the sigma, a common feature in ancient Greek intervocalically), than the name of this plant would be Myotis. In Creosaurus the actual building block is not the genitive case κρέως (kréōs). Beekes and Van Beek in their Etymological Dictionary of Gteek (2010, p. 774) tell us: 'As a first member usually κρεο- (after the o-stems)'. The stem of κρέας (kréas), actually also κρέας (kréas) (= s-stem), behaves somewhat erratically in compounds and imitates o-stem words as suggested by Beekes and Van Beek. Maybe, Creisler was confused by this behavior and thought that κρέως (kréōs) or the specific stem of κρέως (kréōs) was the actual building block, but actually it isn't. The -ω[ς] (-ō[s]) in κρέως (kréōs) has a different genesis than the short -ο (-o) in κρεο- (kreo-). Therefore you can not substitute κρέας (kréas) by κρέως (kréōs). Wimpus (talk) 22:25, 10 July 2026 (UTC)