tag:blogger.com,1999:blog-3653345901774701895.post1529856408455143248..comments2024-03-23T12:02:36.626-07:00Comments on Mark P. Witton's Blog: Remembering IguanodonMark Wittonhttp://www.blogger.com/profile/02524696111911168322noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-3653345901774701895.post-14840286250142643132019-07-10T05:16:16.259-07:002019-07-10T05:16:16.259-07:00Great post, as usual! And an excellent way for som...Great post, as usual! And an excellent way for someone outside the field of palaeontology, yet with a strong scientific interest in it, to catch up with on-going developments!<br /><br />Much like James Appleby above, though, I'm rather confused why such a plethora of new genera would be needed if all share a rather similar bauplan. That is, as I understand, the main differences between the genera lie in size; robustness of various body parts; length of vertebral processes; and size and attachment of the pollex. However, if we look at the genus Bos, there's also a lot of interspecific variation there, such as: the size and shapes of the horns; presence and size of humps; robustness of build (or, at least, appearance, as I by no means claim to be well-versed with the genus); ecology in which species occur; and integument - meaning both colouration/patterning and hair length. These differences don't seem less to me than described as the main variations between iguanodonts. In fact, the main variance with bovines seem to lie at the tribal and subfamilial levels, where differences, moreover, take more notable forms than described here for iguanodonts.<br /><br />Now may be this is just my lack of understanding how the definition of species and genera works, or my selection of a group of domesticated animals as an example (which, from an archaeological perspective has frequently proven difficult to classify), but to me it just seems surprising. Which, I should probably add, is not to discredit the valuable work done by the researchers involved, just a personal question of "why more genera and not species"?Alexander Melchershttps://www.blogger.com/profile/14318543137387525935noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-56084455876335580422014-01-25T07:39:49.031-08:002014-01-25T07:39:49.031-08:00The Thing I never understand about Mantellisaurus ...The Thing I never understand about Mantellisaurus is that it is lightly built, even GSP used an immature individual in the field guide, which reminds me of "Nanotyrannus". Here we have a small, slender, immature animal which comes from a similar time frame to a larger animal, and yet they are still refereed to as different Genus. Which brings me to another point, couldn't various Iguanodonts still be of the Iguanodon genus, just like the numerous species under the Passer genus, which are widespread (I'm looking at you, Dakotadon)Anonymoushttps://www.blogger.com/profile/04394178095047762378noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-75516346751704746242014-01-16T02:21:11.177-08:002014-01-16T02:21:11.177-08:00Indeed. Pterosaur literature is full of similar be...Indeed. Pterosaur literature is full of similar behaviour. It seems several authors are suppressing names attached to small (but diagnostic) type material in favour of likely junior synonyms or, in some cases, creating new binomials which essentially rename valid taxa. The nomenclature and taxonomy of pterosaurs is such a freakin' mess already, and this behaviour really doesn't help.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-10076595613450383132014-01-16T02:11:42.543-08:002014-01-16T02:11:42.543-08:00So there we have it: GSP Taxonomy in a few easy st...So there we have it: GSP Taxonomy in a few easy steps!<br /><br />This might sound silly, but one of things that I find irksome about the 2008 GSP <i>Iguanodon</i> paper - and many of his other taxonomic papers - is the complete lack of detailed images of the specimens he discusses. It's all very simple line drawings, reconstructions and his word on the nature of specimens. I think we've got to the point where imaging actual specimens in detail is so easy and cheap that this is pretty inexcusable, particularly in case as confused as British iguanodonts.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-56429733866859412072014-01-16T00:03:30.150-08:002014-01-16T00:03:30.150-08:00This situation _should_ be a lesson to people to s...This situation _should_ be a lesson to people to stop redefining type species, but the current vogue is to just let renaming do the actual scientific work of evaluating incomplete specimens. So much so that Galton (2013) is advocating using Plateosaurus trossingensis over its senior synonym P. longiceps, because P. longiceps is "only" known from a skull from a closed quarry, while P. trossingensis' holotype is a complete skeleton from an open quarry. :|Mickey Mortimerhttps://www.blogger.com/profile/08831823442911513851noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-13653433271960673012014-01-15T23:50:50.489-08:002014-01-15T23:50:50.489-08:00Back in my review of his Field Guide's ornithi...Back in my review of his Field Guide's ornithischian section, I figured out Paul's taxonomic methodology- " If a taxon is similar to another, but from a different horizon, it's a different species! Doesn't matter if anyone's actually tried to name a distinct taxon from there yet, or if there are actually any differences reported in the literature. If a taxon is from the same horizon as another similar one, they're synonymous! Ignore priority and use the name of the most complete specimen for the taxon. If a species forms a clade with another, they're congeneric! With these three easy steps, you too can lump and split the GSP way. ;) "Mickey Mortimerhttps://www.blogger.com/profile/08831823442911513851noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-82788131766640933592014-01-11T13:52:01.850-08:002014-01-11T13:52:01.850-08:00Thanks - I thought it looked like it "ought&q...Thanks - I thought it looked like it "ought" to grasp across the walking digits, but gut feeling (of a layperson at that) isn't very good at biomech. analysis! Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-53163301434690652272014-01-09T08:06:17.721-08:002014-01-09T08:06:17.721-08:00Whoops - yes, II-IV. My mistake.Whoops - yes, II-IV. My mistake.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-38853939951877355882014-01-08T12:57:38.621-08:002014-01-08T12:57:38.621-08:00Is it not II-IV that beared weight?
--Sean McCabe...Is it not II-IV that beared weight?<br /><br />--Sean McCabeAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-91579304882106646732014-01-08T12:55:13.258-08:002014-01-08T12:55:13.258-08:00So "opposable" digits remained in ornith...So "opposable" digits remained in ornithopods far longer then I realized...<br /><br />--Sean McCabeAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-59109914358222510952014-01-08T07:50:22.724-08:002014-01-08T07:50:22.724-08:00Just realised I only half-answered your comment: d...Just realised I only half-answered your comment: digits II-III were the weight-bearing fingers during quadrupedal locomotion, so are robust, not terribly flexible, and equipped with large, rounded unguals.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-67922034236210967532014-01-08T07:46:31.594-08:002014-01-08T07:46:31.594-08:00Iguanodont manual digit V is the most flexible dig...Iguanodont manual digit V is the most flexible digit of all, able to bend right the way to the palm in at least some species. I'm not sure what the current leading idea is on its function, but it has been suggested as providing a means to hold things, like food or whatever. I must admit to wondering if that's likely: the neck and head can reach much further forward than the hands, and it's not like the animal can easily pass food to its jaws. So yes, other than suggesting it has some grasping/gripping role (maybe for holding conspecifics in various behaviours?), I'm not sure what to suggest it's specific function was.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-89659105877235960652014-01-07T22:09:43.896-08:002014-01-07T22:09:43.896-08:00What's with the odd digit V? Do we know why i...What's with the odd digit V? Do we know why it's so distinct from II-IV? What sort of range of motion does it have compared to the rest of the manus?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-84570339077676837562014-01-05T07:25:55.637-08:002014-01-05T07:25:55.637-08:00I'd be surprised if anyone launched another pe...I'd be surprised if anyone launched another petition about the appropriate taxonomic application of <i>Iguanodon</i>, and am not sure it would be looked on favourably by the ICZN or palaeontologists. It would unnecessarily destabilise a lot of recent work on British iguanodont taxonomy and make more clutter in an area that people have made real efforts to tidy in recent years. The fact that Mantell didn't discover the animal we now recognise as <i>Iguanondon</i> isn't really a valid reason to do that. Moreover, the ICZN does recognise prevailing use and interpretation of taxa, and way more people - laymen and scientists alike - have associated <i>bernissartensis</i> with <i>Iguanodon</i> than they have <i>dawsoni</i>. I've yet to read Norman's promised full overview of this issue, but my expectation is that they'll have greater implications for the history of interpretation of these animals than they will for the taxonomy of the animals themselves.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-29231378007014925612014-01-04T16:26:19.733-08:002014-01-04T16:26:19.733-08:00Wait, if I. anglicus's Identity is discovered,...Wait, if I. anglicus's Identity is discovered, what get's the name, I. bernissartensis, or I. anglicus? I know the former is now the type, but I wouldn't be surprised if someone suggested an ICZN petition to "re" save Iguanodon. I could also see some stupid new rule from the ICZN, in a Manospondolus II scenario (And yes, I Know it's not a nomen oblitum.), with them pulling something along the lines of "Any genus which has had a change of type specie because of dubious validity of the original may be reversed upon discovery of the real identity of the original", when someone points out that mantel didn't actually discover Iguanodon, he discovered Barillium (Or Kukufeldia.).<br /><br />--Sean McCabe Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-65889548774228167732014-01-04T16:12:49.764-08:002014-01-04T16:12:49.764-08:00On a completely unrelated note, probably not the r...On a completely unrelated note, probably not the right place to mention this, Matthew, what ever happened to DinoGoss? Sorry if this is a bad place for this question.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-2292143142386950862014-01-04T08:34:29.336-08:002014-01-04T08:34:29.336-08:00"They were well on their way: Dollo's rec..."They were well on their way: Dollo's reconstructions of Iguanodon were finished by the early 1880s, casts of the skeletons were being wheeled out to museums by the 1890s, and illustrations based on them shortly followed. And, of course, we had sprightly, upright hadrosaur models made by Hawkins as early as 1868."<br /><br />True, but those dinosaurian kangaroos where far from accurate. I'm not saying that he wold get it right, I doubt that. But he could be closer, or less accurate, it would still be a different influence, if it became mainstream. Especially given that he seemed to talk of an active beast.<br /><br />--Sean McCabeAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-59681336815118857712014-01-03T02:59:35.313-08:002014-01-03T02:59:35.313-08:00"According to Wikipedia, Mantell realized nea..."According to Wikipedia, Mantell realized near the end of js life that Iguanodon was a gracile, perhaps even bipedal, and certainly active beast."<br /><br />Indeed. Mantell had been working on a relatively complete skeleton of something like <i>Mantellisaurus</i> and noted the disparate hindlimb/forelimb length. Alas, despite knowing this before the Great Exhibition dinosaurs were constructed, his health prevented him from being especially vocal about it. Plus, the chap he had to convince was world reknowned palaeob*stard #1: Richard Owen.<br /><br />"Imagine what palaeontological history would have been if that was mainstream in the late 1800s."<br /><br />They were well on their way: Dollo's reconstructions of <i>Iguanodon</i> were finished by the early 1880s, casts of the skeletons were being wheeled out to museums by the 1890s, and illustrations based on them shortly followed. And, of course, we had sprightly, upright hadrosaur models made by Hawkins as early as 1868.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-17646702060077303082014-01-03T02:50:05.442-08:002014-01-03T02:50:05.442-08:00"Could Kukufeldia and Barilium be synonyms?&q..."Could Kukufeldia and Barilium be synonyms?"<br /><br />According to Norman (2011), yes. I don't know that everyone agrees because there's no overlapping material between the two. Norman's concept of <i>Barilium</i> contains quite a bit of referred material. <br /><br />It may be of interest that Norman (2011) indicated a paper on the implications of the <i>I. anglicus</i> teeth was in prep, but I don't know if it's out yet.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-9958694077833354572014-01-03T02:41:44.677-08:002014-01-03T02:41:44.677-08:00Thanks for comments here and above, Andrew. I hope...Thanks for comments here and above, Andrew. I hope to cover dryosaurids - probably specifically <i>Valdosaurus</i> here soon. If nothing else, we need more artwork of these things: there's a real dearth of reconstructions of these basal iguanodontians.Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-55970057300701014552014-01-03T01:51:25.741-08:002014-01-03T01:51:25.741-08:00Awesome article! Nice to get a good summary of a v...Awesome article! Nice to get a good summary of a very confusing history...<br /><br />"according to Norman (2011a, b) there's a good chance that the original Iguanodon teeth belong to Barilium."<br />Huh, not Kukufeldia, which looks like its was more contemporary? Apparently the authors of Kukufeldia considered it probably synonymous with I. angelicas but didn't formalize this because they considered the latter dubious. Could Kukufeldia and Barilium be synonyms?<br /><br />Also, apparently Fitzinger attached the name Therosaurus to the "I." angelicas teeth in the 1800s, making this an available genus name now that Iguanodon has been transferred.Matt Martyniukhttps://www.blogger.com/profile/04220900229537564466noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-68419747312426353412014-01-02T18:45:35.755-08:002014-01-02T18:45:35.755-08:00Seconded. My own phylogenetic analyses (McDonald e...Seconded. My own phylogenetic analyses (McDonald et al. 2010, McDonald 2012a, McDonald et al. 2012) have shown that Dakotadon lakotaensis and Mantellisaurus atherfieldensis do not form a clade with Iguanodon bernissartensis. Although I consider Dollodon to be a junior synonym of Mantellisaurus (McDonald 2012b), I endorse Paul's separation of Dakotadon and Mantellisaurus. As Mark alluded to above, there are issues with the diagnoses and criteria used by Paul to establish taxa (see McDonald 2012b and Norman 2012). I also concur that Iguanodon, Mantellisaurus, Barilium, and Hypselospinus (as well as Owenodon and the dryosaurid Valdosaurus) are the best-supported Early Cretaceous British iguanodonts. Add in the Middle Jurassic dryosaurid Callovosaurus and the Late Jurassic Cumnoria, and it's easy to see why Britain's iguanodont record is still one of the best. Andrew McDonaldnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-75095898104142846672014-01-02T13:19:27.972-08:002014-01-02T13:19:27.972-08:00According to Wikipedia, Mantell realized near the ...According to Wikipedia, Mantell realized near the end of js life that Iguanodon was a gracile, perhaps even bipedal, and certainly active beast. Imagine what palaeontological history would have been if that was mainstream in the late 1800s. <br /><br />On iguanodont diversity, let's not forget stuff like Altrhinus, Tethyshadros, Dwarf European forms, and the surprising diversity in hadrosaur proportions, compared to what they are treated as. Like leg length, Kritosaurs and Brachylophosaurs big, Parasaurolophs small, etc. <br /><br />--Sean McCabeAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-73235475891600294062014-01-02T12:11:34.580-08:002014-01-02T12:11:34.580-08:00Paul's taxonomic considerations shouldn't ...Paul's taxonomic considerations shouldn't be ignored entirely. <i>Mantellisaurus</i> and <i>Giraffatitan</i> are 'accepted' genera by even the most conservative palaeontologists and splitting them from their 'traditional' genera has been supported in phylogenetic analyses. That said, the means used to establish some valid Paulian taxa have been criticised (there is a not so subtle undercurrent of frustration in several post-Paul 2008 papers on British iguanodonts, for instance), and it does remain true that the majority of Paul's taxonomy is at odds with that of all other dinosaur workers. This doubtless creates scepticism at his more valid points: it's often not clear which bits are worth taking seriously and which should be put down to his unconventional, intuitive means of classification. With regard to the iguanodonts discussed here, <i>Iguanodon</i>, <i>Mantellisaurus</i>. <i>Barilium</i> and <i>Hypselospinus</i> are probably the best supported taxa: all other newbies should be considered at least 'under discussion' (by some) or highly doubtful (by others).Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.comtag:blogger.com,1999:blog-3653345901774701895.post-13589011625649565232014-01-02T11:43:13.611-08:002014-01-02T11:43:13.611-08:00Thanks for the heads up on the typo Duane - makes ...Thanks for the heads up on the typo Duane - makes a bit more sense now! Mark Wittonhttps://www.blogger.com/profile/02524696111911168322noreply@blogger.com