Talk:Plesiosauroidea

Redundant Page?
Moved from Plesiosaurus: What is the process for merging data? I missed Plesiosaur when I created this page. :( It seems (to me) that the scientific name is more appropriate for a title, so this would be the primary page.  How would you fix links to the other page???  Nodosaurus 22:04, 3 Dec 2004 (UTC)


 * I moved the content to Plesiosaur and shall move this Discussion there too. Plesiosaurus will remain as a link, so nothing is lost. (Compare entry Mosasaur, which includes other genera.) --Wetman 22:24, 3 Dec 2004 (UTC)


 * They look like two separate articles to me. Nodosaurus' article was about the genera, while plesiosaur covered the higher level taxon, Plesiosauria (which is the common usage). A paragraph or two explaining how once all the plesiosaurians were once tossed into the Plesiosaurus genera should cover it. 68.81.231.127 17:04, 15 Dec 2004 (UTC)


 * The common usage in the English language is "Plesiosaur, Plesiosaurs." (And often pronounced, heaven forfend! "sore" instead of, owlish correctness! "sour".) Plesiosauria is taxonomic, but not common English. Let all the general discussion and major distinctions be made here, where the average interested reader will first alight. Then let links continue more specialized discussion under taxonomic designations. Wouldn't that be fair to the reader? --Wetman 18:33, 15 Dec 2004 (UTC)


 * Sorry, but I'm not sure what you're saying... do you want to split it into three pages? I'm not sure that's necessary. Plesiosaur is most commonly used in the broader sense to refer to the whole group of reptiles usually lumped under "Plesiosauria". Since that's the primary meaning, it belongs on the plesiosaur page, with a disambiguation note at the top linking to the genera. I'm not familiar with any pages where the formal taxonomic term has a separate page from the vernacular usage &mdash; for example, aves just redirects to bird. 68.81.231.127 22:18, 15 Dec 2004 (UTC)


 * My intention was transparent: one page, please, at the designation that is used in informed but non-professional discourse: Plesiosaur. Individual taxa among Plesiosaurs might get their own pages (if there's enough material), linked in the text on the Plesiosaur page, so as not to get lost. Fundamental. Page titles that reflect the designation that is used in informed but non-professional discourse are always better style at Wikipedia than belabored pretentious accuracies, don't we all agree?--Wetman 04:36, 16 Dec 2004 (UTC)


 * Oh, that explains the confusion. You're arguing with the wrong person: Nodosaurus is the only person who suggested that; I was arguing for common usage.


 * But, and this is the issue I raised: I don't understand why the two articles were merged. They covered different things (genera vs. everything plesiosaurfragilistic), and while neither was particularly long, they weren't entirely stubby. 68.81.231.127 11:48, 16 Dec 2004 (UTC)


 * I'll add my two cents again. I think there is value in having the separate pages.  I would never (initially) search on Plesiosaur, and would expect to find technical information.  Having a technical page and a nontechnical page would probably make everyone (people searching for info) happy.  They could easily link to each other.  Nodosaurus 22:48, 20 Dec 2004 (UTC)


 * But nothing has been lost lost. A List of plesiosaur species could be created, once the list was so huge it overwhelmed this entry, just with a click on the above red deadend link. Until then, why would you separate the names of genera from their context?  Anyway, anyone looking for "Plesiosaur" at "Plesiosaurus" will be redirected here, to the consolidated information. It's a very brief text, actually.... -Wetman 00:58, 21 Dec 2004 (UTC)

A lot of the material on the Plesiosaurus applied more generally to the entire plesiosaur group, so I was able to merge it all when I expanded it. The new version could use a copyedit, and a fact check... the sizes I found were inconsistent. 68.81.231.127 14:43, 23 Dec 2004 (UTC)


 * Excellent! I've added the sentence, at the end of the 'elasmosaurs' discussion: "See Elasmosaurus for the typical genus." It was the only genus listed in What links Here. If Plesiosaurus has enough genus-specific material to make it a separate entry again, go for it! with a similar link. Isn't this how all the dinosaurs and their kin should be treated: a general discussion, with links to individual genera? --Wetman 15:10, 23 Dec 2004 (UTC)

Plesiosaur page
Um, I'm not sure that I'm in the correct pace to do this - if I'm making a faux pas by adding this here then please forgive me (this is the first time I have tried adding something to the Wikipedia). My intention is to provide some comments/updates for the content of this page.

>Description: Large mosasaurs were pretty long - Mosasaurus hoffmani, for example, got up to 18 metres (Lingham-Soliar, 1995). I'm not aware of any reliable body length estimates for plesiosaurs that exceed these lengths (body mass, of course, is another matter).

>Behaviour: Fish have been confirmed as stomach content in Upper Cretaceous elasmosaurs and polycotylids - see Cicimurri and Everhart (2001) for a review. Is there are reference for the statement 'but it is now clear plesiosaurs gave birth to live young'? (Whilst I agree that this is the more likely scenario, I'm not aware of any published descriptions that have confirmed this yet). The 'buoyancy' vs. 'digestive aid' debate continues unabated - see the Cicimuuri and Everhart ref, for example.

>Families: plesiosaur taxonomy is in a state of flux, but the Polycotylidae appear to be stable and they may be worth mentioning as one of the families of pliosaur. The other stable pliosaur family are the Pliosauridae. Recent work has confirmed that the Rhomaleosauridae are a distinct family from pliosaurids. See O'Keefe (2001) for a recent taxonomy, although there are a couple of updated revisions close to publication and it may be some time before the dust settles. The skull in Kronosaurus is not 3 metres long (more like 2.2) - the figure often quoted from White (1935) is a simple mistake. Maximum size in pliosaurs is problematic, not least because of various tantalising fragments from the Upper Jurassic (and inaccuracies in Walking With Dinosaurs). The large pliosaur known from anything like complete remains is Kronosaurus, with a maximum length of 10 - 11 metres (e.g. about 10 metres for K. boyacensis - Hampe 1992). An isolated lower jaw at the Oxford Museum, which seems referable to 'Pliosaurus' macromerus, is nearly 3 metres long and would have belonged to an animal about 15 metres long. Other fragments of jaw at the Natural History Museum suggest the possibility of even larger animals, but this is as yet difficult to confirm. 10,000 kg is about right for a 10 metre pliosaur. A 20 metre pliosaur would be considerably more than twice that weight.

Is there a reference for 17 metres in elasmosaurs? And perhaps to be consistent (plesiosaurid, cryptoclidid) elasmosaur could be elasmosaurid (although this is a happy case where the vernacular form is unambiguous).

>Classification and history: The spread of good specimens is a little wider than implied here. The first specimens found by Anning (and still some of the best) are from the Lower Jurassic Lias - there are also good specimens of this age from Germany). The marvellous Oxford Clay deposits are Middle Jurassic in age.  The English Upper Jurassic has also produced plenty of specimens.   Australia has good specimens from the Lower Cretaceous, and New Zealand from the Upper Cretaceous.  The Niobrarra Chalk is Upper Cretaceous in age (although it is in the 'mid' K).  There have also been plenty of finds from South America, Japan, and Morocco.  See Ellis (2003) for a summary.

Although long-necked plesiosaurs (the traditional sub order Plesiosauroidea) may be polyphyletic (and I think the jury is out on this), I don't think that anyone has suggested that the elasmosaurs (i.e. = Elasmosauridae) are not a natural group. Some confusion persists due to the tendancy of some European workers to include Jurassic long necked non-cryptoclidid taxa such as Muraenosaurus as elasmosaurids, but this issue should be resolved soon and in any case the meaning of elasmosaur will simply be adjusted to reflect the natural group which includes Elasmosaurus but not Cryptoclidus or Plesiosaurus, whatever that turns out to be.

The traditional sense of 'pliosaur' (i.e. the traditional suborder Pliosauroidea) may well turn out to be polyphylectic.

Walking With Dinosaurs was broadcast in 1999, and as such descriptions of the Monster of Aramberri as 25m/150 tonnes come from the erroneous dimesnions of Liopleurodon in WWD, rather than the other way around. The WWD measurement seemed to result from a (willful?) confusion with the dimensions of blue whales (but that's another story).

I hope this helps. If it is appropriate for me to attempt to integrate this comments onto the page then simply leave a note to that effect - I will check back to this page. If you want to make any changes yourselves, then that's fine as far as I'm concerned.

Cheers, CM


 * Lingham-Soliar, T., 1995: Phil. Trans. Roy. Soc. Lond. 347: 155-180
 * Cicimurri, D., and M. Everhart, 2001: Trans. Kansas. Acad. Sci. 104: 129-143
 * O'Keefe, R., 2001: Acta Zool. Fennica 213: 1-63
 * White, T., 1935: Occasional Papers Boston Soc. Nat. Hist. 8: 219-228
 * Hampe, O., 1992: Courier Forsch.-Inst. Senckenberg 145: 1-32
 * Ellis, R. 2003: Sea Dragons (Kansas Uni Press)


 * CM, you should revamp the entry with your information and references. I'll move your references into the page now, but you would do better than I at the editing. --Wetman 10:31, 6 October 2005 (UTC)

Disputed neutrality: [continued] existence of plesiosaurs
I believe that the first section displays a brief but important bias against the continued existence of these creatures. The short paragraph states that there is "no scientific evidence" that they exist. This is clearly wrong. It should state that what little evidence there is, is "disputed."

Just check out the first external reference listed as "Plesiosaur or Basking Shark? You decide." This is a fairly in depth article arguing that the carcas caught by the Japanese fishing boat in 1977 very well may have been a Plesiosaur-like creature.

The bias comes in because people do not want to believe that these dinosaurs could exist in modern times. Such a proposition is inconsistent with the theory of evolution, which requires a millions-year old earth, whereas Creationism can accomodate a young earth.

I'm sure that these comments will be laughed at by scientists everywhere, but just so you know, there is proof to the contrary if you are willing to look. [unsigned]


 * Actually still living plesiosaurs provide no opposition to the theory of evolution. That is a false argument being provided by many Creationism advocacy groups. Here are four articles that should clear up any confusion you have: [Talk Origins Index to Creationist Claims], [Talk Origins: Sea Monster or Shark?], [Answers in Genesis: Letting rotting sharks lie], [Answers in Genesis: Arguments we think creationists should NOT use]. It does no credit to your hypothesis to continue using arguments long discredited (also you claim plesiosaur is a dinosaur; it is not).

141.213.170.219 15:58, 11 November 2005 (UTC) Jason

more giberish
After reading this article im still confused. one question...is the plesiosaur the loch ness monster or not? by the way im new to this (as you can tell) im doing a report on the loch ness monster and would like to know more about the plesiosaurs and how it could survive so long. [unsigned]


 * Even if the loch ness monster is real, there's no way it could be a plesiosaur (though that's what many people think). First, plesiosaurs breathe air. To sustain a population of them for thousands of years, there would have to be at least 30 or 40 of them in that lake. 30 giant animals coming up to breathe every few minutes would be very hard not to notice! I say thousands of years, not millions, because Loch ness itself is not prehistoric. It was formed by glaciers during the ice age, tens of millions of years after plesiosaurs were already extinct. So, even if plesiosaurs could have somehow survived that long without leaving any fossil trace, you'd have to explain how they got into Loch Ness to begin with. They'd either had to have crawled there over miles nad miles of dry land, or swam through the ice.Dinoguy2 13:50, 17 May 2006 (UTC)

Ignore all of the above, as it is pure speculation. The truth is, nobody knows for sure what the precise physiology of plesiosaurs was, because the fossil records only provide limited information. Paleontologists used to think that the apatosaurus was cold-blooded and dragged its tail, based solely on its similarity to modern lizards. Then after they discovered better-preserved fossils and studied them with more modern equipment, they figured out that it had more in common with birds, was warm-blooded and could indeed hold its tail up. So yes, pending the discovery of further evidence, for all we know the Loch Ness monster could indeed be some modern descendent of plesiosaurs. It's just that some science fans hate to admit when they don't know it all, so you have to read between the lines. 192.54.250.11 (talk) 22:24, 9 July 2013 (UTC)

A tentative plesiosaur genera list
List of plesiosaurs. I copied some of the text from list of dinosaurs for coherence (at least in my view.)

Redundancy: Plesiosaurus page
I noticed there was an entry for Plesiosaurus, which is redundant with the current article. Anyone know how to merge/redirect the links?

Hesperornis as marine dinosaur
"With the possible exception of a flightless, swimming 'bird' called Hesperornis, there were no marine dinosaurs." -- Moved this to talk for now. I think that we have to phrase this carefully to avoid confusing laypeople. Additionally there were several other Hesperornithiformes besides Hesperornis -- 201.51.215.102 18:17, 18 September 2006 (UTC)


 * Is a 'flightless swimming bird' really to be classed as 'marine'? - Ballista 04:58, 19 September 2006 (UTC)


 * And while we're at it, why single out Hesperornis? All birds are considered to be descended from dinosaurs, so you might just as well include seagulls and penguins. I suppose it's worth underlining the point that plesiosaurs weren't dinosaurs!Orbitalforam 16:32, 28 September 2006 (UTC)

The Loch Ness Monster
I have a problem with the showing of Nesse as a living plesiosaur. Mainly for the fact of genetics. Plesiosaurs couldn't raise their head our of the water in the way that pictures of Nesse portray.Solon Olrek 19:06, 14 November 2006 (UTC)


 * I take back my previous statement. Given to the fact that plesiosaurs were in fact mainly bouyent, and stayed submergerged for the most part because they ate stones....does anyone object to me putting this speculation made be scientist in the early 90's in the article?Solon Olrek 04:33, 28 February 2007 (UTC)
 * Yes, unless you include it under popular culture to make it clear it's not scientific, and mention that Nessie has been shown to be a hoax. Dinoguy2 06:20, 28 February 2007 (UTC)


 * I was refering more to what I said about the plesiousaurs not being able to lift their heads above water theory.Solon Olrek 15:29, 28 February 2007 (UTC)
 * Right, but I'm uneasy about giving that much time to nessie in this article as it is. A quick mention and link to the nessie article should be enough, and all the debunking, with cites etc, can go there. Dinoguy2 09:17, 1 March 2007 (UTC)
 * I wasn't planning on mentioning Nesse, but the study that shwoed that plesiosaurs ate stones to counteract their bouyancy.Solon Olrek 15:13, 1 March 2007 (UTC)
 * Ok, but that should go in a paleobiology section, not the monster section, no? Dinoguy2 22:46, 1 March 2007 (UTC)
 * Point takenSolon Olrek 15:41, 2 March 2007 (UTC)

Hate to beat a dead horse, but is there any harm in adding a Loch Ness Monster link under "See Also"?Stuthehistoryguy (talk) 19:52, 27 July 2010 (UTC)
 * It's not the best idea we've ever had. Dinoguy's suggestion is probably better, but I'm tired of pop culture sections that degenerate into "spot the animal". J. Spencer (talk) 23:36, 28 July 2010 (UTC)

Watch out for assertions like "couldn't lift its head". They used to think the apatosaurus was cold-blooded and dragged its tail, and then they figured out that no, that was not the case. The precise physical capabilities of long-dead creatures can only be guessed at, since fossils can only tell us so much. For all we know, they could indeed lift their heads by some means not evident in the fossils studied thus far.


 * Parsimony, dude. Parsimony. Abyssal (talk) 23:15, 9 July 2013 (UTC)

Popular Culture section
The pop culture section of this article discusses a creature in King Kong that may have been a Tanystropheus, which the article says "swam in the ocean, catching fish, much like plesiosaurs." The tanystropheus article itself contradicts that and there's no agreement on the subject. Frankly the entire statement there is a little... well anyway, unless there's general disagreement I'm going to delete the line. 131.24.119.11 20:04, 2 March 2007 (UTC)
 * Unless there's an actual reference stating what species it was supposed to be, assigning it to one sounds like original research. Dinoguy2 23:33, 2 March 2007 (UTC)

There is far too much in this article about fiction. I would suggest moving "Alleged Living Plesiosaurs" either to the Loch Ness Monster article or to its own article. It may be fun, but it lacks sources and is not very professional. Smallpond 19:33, 4 May 2007 (UTC)


 * Why is it everytime evidence contradicts popularly held beliefs people hold more faith to "science" than they do to evidence? To say that evidence is wrong because it contradicts your belifs, and is therefore fiction takes a great deal of faith in your beliefs. Let's be scientific and present all current evidence as such whether or not you find it to be comparable to your sense of professionalism. [unsigned]

Actually I was wonder if there was an article on alleged plesiosaur discoveries and hoaxes. I don't believe they still exist, but I still come across people who do and say the sighting go beyond Loch Ness. If there was such a page, maybe a link to it would not be out of order? —Preceding unsigned comment added by 71.17.194.141 (talk) 01:40, 16 March 2011 (UTC)

Is it just me...?
Is it just me, or is the Cryptoclidus model shown in the article the model of the Loch Ness Monster made by Channel 5, or are they just similar? Elasmosaurus (talk) 03:17, 19 December 2007 (UTC)

So how big were plesiosaurs?
There doesn't seem to be anything in this article to indicate the size of a typical plesiosaur. Perhaps the nearest suggestion of size offered is comparing it to "a snake threaded through the shell of a turtle". So are we meant to conclude from this that it is about the size of a turtle? Or smaller? Or larger? There is no indication. --Geronimo20 (talk) 21:49, 16 March 2008 (UTC)


 * Plesiosaur denotes any species from the order Plesiosauria or the suborder Plesiosauroidea, not a single species. There is a large variation of size within even the suborder - a short browsing yielded mature lengths between 2.5 and 12m. --Stephan Schulz (talk) 21:58, 16 March 2008 (UTC)


 * Thanks for that Stephan. But the real point is that, given that so many of us are not specialists here and are more taxonomically challenged than you are, it would be nice to state what you just said in the article itself. --Geronimo20 (talk) 22:38, 16 March 2008 (UTC)


 * Ok, added a sentence. I'm not an expert, either, so I just choose two examples. --Stephan Schulz (talk) 22:57, 16 March 2008 (UTC)

Earliest fossil found?
I just added a fossil range box since it makes this article more standardized, but couldn't find any information on how old the earliest fossils of plesiosaurs actually are. I assumed that "early jurassic" hints at approximately 190 mya, but have no way of verifying this. Please change this if you have more information. --Heburnslikethesun (talk) 22:45, 9 January 2009 (UTC)

Okay, let's make this clear.
There should be something in there about the fact that Plesiosaurs were not dinosaurs. However, I think that they were related because they might have both been archosaurs. Can someone check this? Paleo Kid (talk) 20:20, 10 December 2009 (UTC)
 * They were not archosaurs. You might be confusing them with pterosaurs. FunkMonk (talk) 20:45, 10 December 2009 (UTC)

Okay. Well, that clears it up. Still, I think that something should be written about the Pliosaurs's ancestors. Paleo Kid (talk) 22:37, 10 December 2009 (UTC)

non-UK eyhibits

 * Specimens are on display in museums in the UK, including New Walk Museum, Leicester, The Yorkshire Museum, The Sedgwick Museum in Cambridge, Manchester Museum, Warwick Museum, Bristol Museum and the Dorset Museum. A specimen was put on display in Lincoln Museum (now The Collection) in 2005. Peterborough Museum holds an excellent collection of plesiosaur material from the Oxford Clay brick pits in the area. The most complete known specimen of the long-necked plesiosaur Cryptoclidus, excavated in the 1980s can be seen there.

This makes it sound as if plesisaurs are on exhibit only in the UK. The US is mentioned in passing (a figure caption), while, e.g., the State Museum of Natural History Stuttgart, the Tübingen museum and others are not mentioned at all, despite plseiosaurs on exhibit that make experienced people go 'Wow!'. Can we either try for a fuller, more representative list, or drop the UK bias by removing the section? HMallison (talk) 00:20, 3 April 2010 (UTC)

Contradiction as to period of first appearance
The infobox says they date to the Late Triassic, but the opening section says they first appeared in the Early Jurassic. Could anyone please tell me who's right?--Thylacine24 (talk) 20:28, 4 October 2021 (UTC)

Move discussion in progress
There is a move discussion in progress on Talk:Plesiosauria which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 17:34, 5 February 2022 (UTC)