Talk:Pelorosaurus

Nomenclature of Pelorosaurus

The authorship for Pelorosaurus conybearei should be changed from Mantell, 1850 to (Melville, 1849). The webpage for the taxonomic history of Pelorosaurus at Mikko's Phylogeny Archive (http://www.fmnh.helsinki.fi/users/haaramo/metazoa/deuterostoma/Chordata/Archosauria/Sauropodomorpha/History_Pelorosaurus.html) correctly attibutes the authorship of P. conybearei to (Melville, 1849). Mantell (1850) officially created created Pelorosaurus as a new genus for "Cetiosaurus" conybearei.

Mantell G. A. 1850. On the Pelorosaurus; an undescribed gigantic terrestrial reptile, whose remains are associated with those of the Iguanodon and other saurians in the strata of the Tilgate Forest, in Sussex. Philosophical Transactions of the Royal Society of London 140: 379-390.

The synonymy of Dinodocus, Oplosaurus, and Ornithopsis with Pelorosaurus performed by McIntosh (1990) has been rejected, because Dinodocus, Oplosaurus, and Ornithopsis are nomina dubia (Upchurch and Martin, 2003). Oplosaurus may be the first record of the clade Turiasauria from the Cretaceous (http://www.users.qwest.net/~jstweet1/sauropoda.htm), and Upchurch et. al. (2004) consider this genus valid and distinguishable from Pelorosaurus.

McIntosh, J. S., 1990: Sauropoda. 345-401 in Weishampel, D. B., Dodson, P., & Osmólska, H. (eds.), 1990: The Dinosauria. –University of California Press, Berkley, Los Angeles, Oxford, 1990 xvi-733.

Upchurch, P. & Martin, J., 2003: The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England. –Journal of Vertebrate Paleontology: Vol. 23, #1, pp. 208-231.

P. Upchurch, P. M. Barrett, and P. Dodson. 2004. Sauropoda. In D. B. Weishampel, H. Osmólska, and P. Dodson (eds.), The Dinosauria (2nd edition). University of California Press, Berkeley 259-322.

Thanks for bringing this to my attention, Firstfron! Now I cannot pretend to be a great student of Pelorosaurus. I am however especially interested in Victorian dinosaurs and was trying to help to to expand the stub, and have done some serious research. You are right, of course- many authors equate Cetiosaurus conybeari with Pelorosaurus conybeari, and on that basis Melville should have precedence. But the generality of the scientific community seems to continue to use the name Pelorosaurus conybeari, if only as a nomen dubium. There may be some taxonomic or historical reason why this is the case. And the article notes that the name may in fact be a n.d. Perhaps sometime soon a consensus will establish P.conybeari as a junior synonym of C.conybeari, and we will have to edit. But isn't Cetiosaurus as nearly as messy as Pelorosaurus? It's interesting to note that the Wikipedia entry on Cetiosaurus does not list C.conybeari as a species, so perhaps it is itself a n.d? Upchurch suggests that Cetiosaurus medius, the type, is invalid, which would make the type C. oxonensis (1871). Pelorosaurus would then certainly have precedence. So the situation may not be as clear as Mikko's Phylogeny suggests. In any case I feel it safer to leave things as they are.

As to Dinodocus, Oplosaurus, etc: the taxonomic history of Pelorosaurus is, as you know, long and convoluted. The list of species and their relationships is taken from Dino Russ, which is why I originally listed that site as a reference. I dare say there are other interpretations. I don't understand why equating one or more species of Pelorosaurus with one or more of another sauropod 'lacks seriousness' because those other species may be nomina dubia. Could you please explain that to me? But in any case, we are dealing with the opinion of a small number of authorities, authorative as they may be. I could not edit the article to favour Upchurch's opinion unless I was sure it represented the consensus of the scientific community. Having said all this, do edit the article if you wish, but I do not think your edits should replace the present information, but be presented as alternate interpretations. Cheers!--Gazzster 21:48, 2 January 2007 (UTC)

"Cetiosaurus conybeari.. Pelorosaurus conybeari"... ye gods, I hope these don't have anything to do with the nomen oblitum Megalosaurus conybeari... ;) Those Victorians certainly had a fast and loose approach to taxonomy! Dinoguy2 06:38, 3 January 2007 (UTC)

Oh, as to the actual issue here, P. conybeari is the type, referred to it's own genus by Mantell 1850 after having been named as a new species of Cetiosaurus by Melville 1849, right? I'll modify the taxobox authorities accordingly. All this means is that the genus and the binomial have different authorities--pretty common, so not really a sticky situation. Dinoguy2 06:49, 3 January 2007 (UTC)

Actually, Cetiosaurus conybeari was a new name for sauropod specimens described by Owen (1842) as Cetiosaurus brevis. Therefore, C. conybeari is a junior objective synonym of C. brevis (Upchurch and Martin, 2003). Pelorosaurus conybeari is based on a different specimen (NHM UK 28626) than C. conybeari. Thus the authorship for P. conybeari should be changed from (Melville, 1849) to Mantell, 1850.

Owen, R. 1842. Report on British fossil reptiles, Part II. Reports of the British Association for the Advancement of Science, 11: 60–204.

Upchurch, P. & Martin, J. 2003. The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England. Journal of Vertebrate Paleontology, 23: 208–231. 68.4.61.237 (talk) 00:30, 31 August 2010 (UTC)Vahe Demirjian

Well, things are a bit more complicated than that. Mantell meant Pelorosaurus conybearei to be the new name of Cetiosaurus conybeari. This implies that the type material of C. conybeari is the type of Pelorosaurus conybearei too, to which the humerus was referred. The humerus is however, arguably the genoholotype of the genus Pelorosaurus. If the specimina are to be considered cogeneric, as Mantell obviously did, this poses no contradictions. If not, there is a problem.--MWAK (talk) 18:17, 11 September 2010 (UTC)

Image

The image has been removed on the grounds that it's anachronistic. It was an old print, the dino was in an urban setting, and human beings are running away from it. It is obviously from a piece of fiction. I suppose the caption should have sourced the image. So I can sort of see the editor's point, but still, I think the image was pretty cool. And it was fairly accurate for a brachiosaur- no glaring scientific innacuracies as far as I could see. I'd like to see it back. What do you think? There are early depictions of Anchisaurus and Ceratosaurus and other dinosaurs in their articles. And I don't think you will find a 100% accurate image of Pelorosaurus, because it is imperfectly known. So why not use the image, properly captioned?--Gazzster 22:47, 8 January 2007 (UTC)

As per Wikiproject Dinosaurs image guidelines, historical images are appropriate if source information and context are given. They should not be in the taxobox, however. If the image is from a movie or an illustration for a piece of fiction (sounds like it based on the setting), it should be in a pop culture section. It is pretty inaccurate, by the way--much too bulky compared to modern restorations, the skull looks... goofy, broad, and non-brachiosaurid, and the front legs include toes and claws, which sauropods did not have. Dinoguy2 23:14, 8 January 2007 (UTC)

Right then. Maybe somebody has a photo or drawing of the fossil material.Sauropods had no toes or claws? Didn't Apatosaurus and others have some pretty wicked claws on their front feet?--Gazzster 05:49, 9 January 2007 (UTC)

Yeah, some sauropods had a large 'spike' that's basically a vestigial toe claw, possibly used in intra-specific combat or something. Ironically, these species still lack toes--the toes were lost, and that single claw became fused to the metacarpal 'stumps' left behind. Anyway, I do think it would be cool to keep that image, if we can dig up the source information and list it in the caption. Dinoguy2 18:39, 9 January 2007 (UTC)

The source, www.copyrightxpired.com, lists it not as Pelorosaurus but as Gigantosaurus, published in Scientific American in 1914. I've moved the image to that article. Dinoguy2 00:33, 10 January 2007 (UTC)

Type species of Cetiosaurus

Cetiosaurs brevis cannot be considered the original type species of Cetiosaurus because: (1) Owen intended to base Cetiosaurus on the material now known as Cetiosaurus medius rather than C. brevis; and (2) Steel (1970) designated C. medius Owen, 1842 as the type species of Cetiosaurus in congruence with the original use of Cetiosaurus for the sauropod from the Middle Jurassic Inferior Oolite. Thus, the pages for Cetiosaurus and Pelorosaurus need updating.

R. Steel. 1970. Part 14. Saurischia. Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology. Gustav Fischer Verlag, Stuttgart 1-87.

P. M. Upchurch and J. Martin. 2003. The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England. Journal of Vertebrate Paleontology 23(1):208-231. —Preceding unsigned comment added by 68.4.61.237 (talk) 23:50, 22 December 2008 (UTC)

By all means, update the pages as appropriate.--Gazzster (talk) 06:54, 23 December 2008 (UTC)

Confusion

After reading the article, I am confused. Is there any valid species left in the genus? Is P. conybearei valid, or does it belong to Cetiosaurus? 84.186.75.51 (talk) 13:43, 29 July 2010 (UTC)

I'm not an authority on the intricacies of Victorian sauropod names, but I think the article has turned shades of gray into black and white. C. brevis was thought to be the type species by Upchurch and Martin (2003), but it looks like it was really supposed to have been C. medius all along (http://www.miketaylor.org.uk/dino/pubs/upchurch-et-al-2009/UpchurchEtAl2009-BZN-case-3472-cetiosaurus-type-species-oxoniensis.pdf). Additionally, C. brevis may or may not be based on the same individual as Pelosaurus conybearei. The upshot is P. conybearei is the only diagnosible species of Pelorosaurus that belongs in Pelorosaurus, and if it is the same as Cetiosaurus brevis, the name would more properly be Pelorosaurus brevis. J. Spencer (talk) 23:09, 29 July 2010 (UTC)

Species list update

Looking at the species list, I don't see any reason to retain the list of sauropods misassigned to Pelorosaurus (Neosodon, Gigantosaurus, Ischyrosaurus, Duriatitan, Ornithopsis leedsii, Morinosaurus, Ornithopsis, Dinodocus, Oplosaurus) as these are either recognized as distinct or unrelated to Pelorosaurus. 68.4.28.33 (talk) 16:41, 7 July 2013 (UTC)Vahe Demirjian

Source for different type specimens

Several places in the article state that the genus and species are based on different type specimens. None are sourced. I can't find any mention of this in the Taylor and Naish 2007 Xenoposeidon paper, at least. In fact, in that paper they seem to imply that the humerus and caudal are treated as a syntype series, and there is no mention of anybody formally selecting a lectotype for either the genus or the species. In fact, the article right now seems to agree: "Mantell not only used the sauropod material of C. brevis as the type of Pelorosaurus conybeari but also a large humerus" (i.e. the caudals of conybeari/brevis are its syntypes, to which Mantell added the humerus when he named Pelorosaurus). Owen then designated the humerus what we would call the lectotype, not holotype, from the syntype series of the caudal and humerus. The article says he chose the humerus as the type of P. conybeari the species, not Pelorosaurus the genus. I don't have some of the other articles, so is this discussed anywhere else or is the conclusion that the genus and species have different types OR from synthesizing this info? My understanding from the sourced portions of the article is this:

1. C. brevis named based on a syntype series of sauropod caudals and iguanodont bones.
2. C. conybeari named for the same caudal series, iguanodont material removed from syntype.
3. Pelorosaurus created as new genus name based on the caudal series and humerus, humerus added to syntype of what is now P. conybeari.
4. Owen designates the humerus the lectotype of P. conybeari.

If I have this right, then if the humerus and caudals belong to different species, the caudals will need a new genus and species name, because while Owen made the humerus the lectotype of conybeari, nobody ever made the caudals the lectotype of brevis, which is what would need to happen to be able to say the genus and species had different types. Note that because conybeari is the type species of Pelorosaurus, they can't have different type specimens. brevis does not seem to have a type specimen, just a syntype series which includes the type specimen of Pelorosaurus, so there's not really an issue even with the new combination. If I have this wrong, then we need more sources and/or a rewrite to make it more clear. Wiki should be understandable by your average High School senior, so if somebody fairly well versed in this stuff can't make heads or tails of an article, it's a massive failure ;) Dinoguy2 (talk) 11:06, 6 June 2015 (UTC)

I think MWAK wrote some of it, but not sure if he has seen this section, so here's a ping. FunkMonk (talk) 01:43, 8 June 2015 (UTC)

Well Dinoguy, the "average high school senior" would not have much knowledge of the subject, so various preconceptions would not get in the way of his understanding ;o). Your basic mistake is: "Note that because conybeari is the type species of Pelorosaurus, they can't have different type specimens". But that's not true for the nineteenth century. In those days it was perfectly normal to name a genus only and indicate a genoholotype (that's why there is a concept "genoholotype" in the first place). Mantell exemplifies this in his naming article: he first very clearly makes the humerus the type of the genus Pelorosaurus and then just as clearly makes Cetiosaurus conybeari the type species. In 1850 there was no contradiction in this.

But, you may ask (and indeed you did ask), would this somewhat inelegant procedure not simply add the humerus to the C. brevis syntype series, from which series Owen subsequently could designate the humerus as the lectotype, problem solved, case closed? Well no, because you are not allowed to expand the syntype series. Any further specimens referred to a taxon subsequent to the naming article are at best plesiotypes. So, Owen could not possibly designate the humerus as the lectotype. And indeed, he didn't even try to. He merely attempted to gloss over the fact that C. brevis was the real type species. The situation was discovered by Steel (1970), commented upon by Ostrom (1970) and confirmed by Upchurch (2003). But in such technical discourse that the gist of the matter might escape the proverbial senior high school student, that paragon of obtuseness, so we better spell things out for him. Of course, it's all just a taxonomic curiosity. Upchurch's position is that because all the specimens are undiagnostic anyway, you can safely refer to the material using the name P. conybeari, a nomen dubium. And thanks for the ping, Funkmonk, I indeed hadn't noticed Dinoguys remarks.--MWAK (talk) 07:34, 8 June 2015 (UTC)

Also it should be added that under modern articles 42.3 and 67.1. ICZN the type species itself is the type of the genus: <<The name-bearing type of a nominal genus or subgenus is a nominal species called the "type species">>. So a genoholotype is simply disregarded should it belong to a different taxon than the type species and this way any nomenclatural conflict is prevented. On further reflection, I agree that some rewriting is due :o).--MWAK (talk) 08:10, 8 June 2015 (UTC)

"Well no, because you are not allowed to expand the syntype series." Even back then? As you say, the rules were more relaxed. Is there a source for any of this? "But in such technical discourse that the gist of the matter might escape the proverbial senior high school student, that paragon of obtuseness" I'm not sure if you're trying to be sarcastic here, but do you think Wikipedia articles should be written with professionals in mind? Because Wikipedia disagrees with you, and professionals can access the literature if they want arcane jargony details. Dinoguy2 (talk) 13:19, 8 June 2015 (UTC)

But it is you who invoked modern rules when trying to decide whether the humerus might be the lectotype. Justifiably so, because certainly Owen himself had no intention whatsoever of designating a lectotype. Now, by those modern rules it is impossible that the humerus is the lectotype. The same rules ultimately solve the matter by implicitly treating genoholotypes as irrelevant for nomenclature.

Wikipedia articles really shouldn't worry too much about their target audience. About certain subjects a secondary literature is available; it is the humble task of an encyclopedia to present this knowledge as coherent and adequate as possible. An arcane or academic style should be avoided, as well as all kinds of "babble" and jargon. This, of course, does not imply that the correct terminology should not be used when applicable. To say "Every night the Eiffel Tower is flooded with electromagnetic radiation of 400 nm wavelength" is ridiculous but "The human eye sees blue light when hit by blue light" is inane as well.

In this particular case however, the point I made was that the technical literature is rather obscure and therefore had best be explained to the reader, professional or otherwise. Indeed professionals have (not so often as they would like) access to the literature. But normal people don't and might still like to know about these matters. To call them "jargony details" confuses two issues. Issue one: can any subject be too difficult to be mentioned on Wikipedia? I think no policy implies this. Issue two: are these details so minor that they are irrelevant to the subject Pelorosaurus? I don't think that this is defensible. The subject is after all, the animal the name refers to. But here there might be two. Can the humerus be simply neglected for not belonging to the type species? Hardly, because for over a century it was seen as the type. Gee, was this by some mistake? No, by a deliberate misrepresentation by one of the most eminent paleontologists of his day. How could he get away with it? Because the original author, Mantell, made the humerus the holotype of the genus but other fossils its type species. Not really a detail. And not all that arcane either :o).--MWAK (talk) 15:58, 8 June 2015 (UTC)

So, here we are debating how the rules apply to Pelorosaurus on the talk page, in the middle of a nice session of original research. Do any published sources spell this out? If not, we can't. Dinoguy2 (talk) 18:12, 8 June 2015 (UTC)

Well, Upchurch (2003) explicitly states that the humerus is the holotype of Pelorosaurus, that the vertebrae are the type specimens of C. brevis, that P. conybeari is a junior synonym of C. brevis because of Melville failing to understand what was the correct way of removing the iguanodont material from the syntype series and that there is no proof that the humerus and the vertebrae are of the same animal. As said, he doesn't see it as much of a problem because the material is undiagnostic.--MWAK (talk) 20:31, 8 June 2015 (UTC)

Authorship and synonymy of Pelorosaurus conybeari

This has been discussed before, but I suppose it's my turn to bring it up: I am confident that Pelorosaurus conybeari is not an objective junior synonym of Cetiosaurus brevis. Rather, this situation has come about as the result of confusion of three names: Cetiosaurus brevis Owen, 1842, Cetiosaurus conybeari Melville, 1849, and Pelorosaurus conybeari Mantell, 1850, the last of which is the type species of Pelorosaurus. C. brevis Owen, 1842 and C. conybeari Melville, 1849 are indeed based on the same set of caudal vertebrae, making the latter an objective junior synonym of the former, but P. conybeari Mantell, 1850, is separate, and the humerus is its holotype. Here are the exact quote of the passages in which Mantell named Pelorosaurus: First, after describing the humerus, he states:

These data appear to me sufficient to warrent the establishment of a new genus for the colossal air-breathing reptile to which this remarkable humerus belonged, and I propose the name of Pelorosaurus to indicate the enormous magnitude of the original.

Later, he states:

From the facts described the following inferences result:— 1st. Upon the evidence of the humerus alone, the existence during the Wealden æra, of a stupendous terrestrial Saurian, generically distinct from any previously described; this reptile I propose to name Pelorosaurus Conybeari. 2ndly. The great probability that the four large anterior caudal vertebrae with the chevron bone, termed Cetiosaurus brevis by Professor Owen, and the two median caudals found in the same stratum as the humerus, and at no great distance from it, belong to the same species...

Not only does Mantell explicitly state that he is establishing Pelorosaurus conybeari "upon the evidence of the humerus alone," at no point does he explicitly indicate that his Pelorosaurus conybeari is meant to be a new genus for Melville's Cetiosaurus conybeari. At one point, he does state the following regarding the caudal vertebrae:

When these splendid fossils were first discovered, I referred them to the Iguanodon; subsequently they were named by Professor Owen Cetiosaurus brevis; and lastly, Dr. Melville and myself, in my Memoir on the Iguanodon, suggested the necessity of adopting a different specific appellation, and proposed that of "Conybeari;" we were unwilling to remove them from the genus Cetiosaurus, till corroborative evidence was obtained to justify the change.

However, this falls short of indicating that C. conybeari Melville, 1849 is the type species of Pelorosaurus. As such, it appears to me that Mantell is naming a new species, Pelorosaurus conybeari, and designating the humerus now known as NHMUK 28626 as its holotype. His decision to tentatively refer the type specimen of C. brevis/C. conybeari to his P. conybeari is nomenclaturally dubious, but does not refute my point. However, this is Wikipedia, and we must follow what the sources say rather than argue about interpreting text. To that end, I point out that until relatively recently, Pelorosaurus conybeari Mantell, 1850, based on the humerus, was consistently recognized as the type species of Pelorosaurus. Lydekker (1888) lists Cetiosaurus brevis and Pelorosaurus conybeari separately and regards the caudals as the type of the former and the humerus the type of the latter, which he attributes to Mantell. Steel (1970) and Ostrom (1970) both explicitly distinguish between Cetiosaurus conybeari Melville, 1849 and Pelorosaurus conybeari, the former being based on the caudals and the latter on the humerus. McIntosh (1990) lists the type species of Pelorosaurus as Pelorosaurus conybeari Mantell, 1850. Upchurch et al. (2004) also distinguish between Pelorosaurus conybeari based on the humerus and Cetiosaurus conybeari based on the caudals, and attribute P. conybearei to Mantell, 1850:

Pelorosaurus conybeari is based on a humerus from Tilgate Forest, West Sussex, England (Mantell 1850). Four proximal caudal vertebrae found a few meters from this humerus were named “Cetiosaurus brevis” by Owen (1842b) and C. conybeari by Melville (1849).

The conflation of Cetiosaurus conybeari Melville, 1849 and Pelorosaurus conybeari Mantell, 1850 appears to be a relatively new development. Naish and Martill (2001) is the earliest work I am aware of to regard Cetiosaurus conybeari Melville, 1849 as the type species of Pelorosaurus, though they state that the name is "here restricted to the type humerus and the remainder of the original material is retained under Cetiosaurus brevis". Upchurch and Martin (2003) also conflate the two species, and state that Mantell (1850) believed the humerus and vertebrae belonged to the same individual. However, they appear to be incorrect as I cannot find any passage where Mantell makes such a claim. Taylor and Naish (2007) are the first to specifically make the claim that Pelorosaurus conybeari is an objective junior synonym of Cetiosaurus brevis, but state their intention to petition the ICZN to suppress C. brevis. Upchurch et al. (2011) regard Cetiosaurus conybeari Melville, 1849 as the type species of Pelorosaurus and list the caudal vertebrae and humerus as syntypes. Despite viewing C. brevis and P. conybeari as synonyms, they choose to use P. conybeari. To sum up: there is clear precedent in the literature to regard Pelorosaurus conybeari Mantell, 1850, as the type species of Pelorosaurus, with the humerus NHMUK 28626 as its holotype. The few recent papers to have argued otherwise are, in my opinion, incorrect in that regard, and moreover regard the potential synonymy of C. brevis and P. conybeari as undesirable. The combination Pelorosaurus brevis is scarcely used in the literature and, in my opinion, not justified by the sources. I wouldn't bring this up if I didn't feel that the available sources are sufficient to cast significant doubt on the taxonomy currently presented in the article. Ornithopsis (talk) 03:09, 31 March 2022 (UTC)

References