The elephant in the living room: Amphicoelias brontodiplodocus

October 7, 2010

Well, this is frustrating.  Over on the VRTPALEO mailing list, all the talk at the moment is of the new paper by Henry Galiano and Raimund Albersdörfer (2010), describing their rather comically named new species Amphicoelias brontodiplodocus.  And to be fair, the material they’re describing is sensational, and the photographs in the paper are pretty good.

 

Galiano and Albersdorfer (2010:fig 10A-B): Above, cervical vertebrae 7-10 of Amphicoelias brontodiplodocus specimen DQ-TY; below, corresponding cervical vertebrae of Diplodocus carnegii holotype CM 84, modified from Hatcher (1901: plate III)

 

But I don’t want to talk about that.

There are other things I do want to talk about, but I can’t help feeling that whatever else we cover here at the moment, everyone is going to be thinking “Yes, but what about Amphicoelias brontodiplodocus?”  So I don’t think I can go on to write about the things I want to before we’ve at least acknowledged the existence of this paper.

And yet, and yet …  I have so many problems with this paper, even before we get to the controversial part, namely the conclusion that Diplodocus, Barosaurus, Apatosaurus, SupersaurusSuuwassea, Tornieria and Eobrontosaurus are all congeneric with Amphicoelias — more precisely, conspecific with the single species Amphicoelias altus.

Aside from the a priori unlikelihood of that, we have these problems:

  • First, and maybe most important, the specimens described in this paper are all privately owned, so whatever conclusions might be gleaned from examining them are not replicable by other scientists.  For the Society of Vertebrate Paleontology, that’s a deal-breaker right there (and I am in full agreement).
  • Second, the new paper doesn’t seem to be published: at least, no-one’s yet claimed that it exists in numerous identical hardcopies, so for ICZN purposes the new name is a nomen nudum.  (That will surely change, though: I am confident that Dinosauria International, LLC are perfectly capable of printing off a hundred copies and sending them out to libraries.)
  • Third, the paper doesn’t seem to have been peer-reviewed: at least, there’s nothing in the acknowledgements that indicates that it was.  It doesn’t seem to have been edited in anything like the usual sense either.
  • Fourth, there is mechanical evidence of enormous sloppiness in the composition of the paper.  For example, many cited papers are not included in the REFERENCES CITED section, and most of the references that are included are not in fact cited in the paper.  As an example, my own Taylor et al. (2009) is cited but not referenced, while Taylor and Naish (2005) is referenced but not cited.  Lots of Upchurch papers in the bibliography are never cited.  That doesn’t give me confidence about the rest of the work.
  • Likewise, the paper is rife with typos and grammar errors, such as this from page 28: “A. louisae is by far the most widely acclaimed example, and B. excelsus skeleton mounted and exhibited in the Peabody museum. Despite the familiarity of these Apatosaurus specimens various aspects of it [sic] skeleton remain poorly known.”  Not a killer, but again it doesn’t give me confidence.
  • brontodiplodocus” is a stupid name.

Against that backdrop, consider the radical taxonomic hypothesis.  All Morrison formation diplodocids (and some from elsewhere) are considered to belong to a single species, Amphicoelias altus … except for the new specimens, which belong to the new and separate species A. brontodiplodocus.  In other words, we’re being asked to believe that the new specimens are more different from all other Morrison diplodocids than any of them are from each other.  And yet we’re brought to this conclusion by the very animals that are apparently not as similar.  It’s as though I discovered dogs, and thereby concluded that lions, cheetahs and house-cats are are all the same species.

So this is not just a matter of extreme taxonomic lumping: it’s weirder than that.  It’s “all the other stuff is just a single species except the one we’ve discovered which is different”.

The point

As Tom Holtz is fond of saying, extraordinary claims demand extraordinary evidence.  I’m not going to come out and say it’s impossible that all Morrison diplodocids except the new specimens were conspecific.  But if I were the one setting out to propose such a heterodox hypothesis, I would do myself every possible favour: I’d do it from properly accessioned specimens in public museums, I’d publish in a recognised peer-reviewed journal, I’d take care to get my nomenclature right, match up my citations and references, and generally dot the i’s and cross the t’s.

Until that’s done with this new material, I’m not sure there’s much point in investing a lot more effort in evaluating the phylogenetic/taxonomic claims.

(Henry, I know you’re an occasional reader here.  Sorry to be so negative, but I’m sure you’ll understand that I have to call ‘em as I see ‘em.)

References

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54 Responses to “The elephant in the living room: Amphicoelias brontodiplodocus

  1. Charles Epting Says:

    Alright, I’m just getting around to reading the paper now, but before I even begin 2 things stuck out that are already starting me off on a bad foot–
    1) “Twinky”? “Sleeping Beauty”? I get if you name a specimen Lucy, or Willo, or whatever…but Twinky? I don’t know, just rubs me the wrong way.
    2) The table of contents lists the new species as “Amphicolias Brontodiplodocu”. You can’t even get the name of your own new species right?

    Anyways, I’ll post my opinions when I’m done reading


  2. Second, the new paper doesn’t seem to be published: at least, no-one’s yet claimed that it exists in numerous identical hardcopies, so for ICZN purposes the new name is a nomen nudum. (That will surely change, though: I am confident that Dinosauria International, LLC are perfectly capable of printing off a hundred copies and sending them out to libraries.)

    Yeah, but would they have if no one had pointed out publicly that this was the case?!?


  3. I’m curious what the Amphicoelias “brontodiplodocus” specimens actually are. Any ideas from the SV-POW team?


  4. The first thing that made me roll my eyes at this paper was that, despite claims, the illustrations are actually very small. It is hard to see the details of vertebrae that are several feet long, or other material that is compared with sometimes very bad lighting. Sure, the color plates are … in color! But this does not excuse the lack of any clarifying illustration, or the ability to render long bones or vertebrae is a way that permits them multiple views and comparably closeups with which to compare material. Thus, the illustrations are NOT very good and up to par with (say) Mike’s own Brachiosaurus paper (which barring the lack of photos of most of the material is really how it should be done).

    Secondly, it should be noted that the authors decided the “extraordinary” method of NOT comparing their “taxon” (which they argue could easily be more than one) to other taxa was worthwhile, so instead precluded their taxon was a single form, and because of this decided to lump everything else. This despite lumping all of “everything else” into the oldest available container to use it. Extraordinary indeed. The authors make the further claim that sexual dimorphism accounts for variation, while at the same time also discern their “taxon” from each species distinctly (ironically noting the variation of their sample).

    They have, in short, graded the generally “family” level down to the “species” level, rendering other taxonomy null. Funny stuff.

    It should be interesting if anyone argues that the most recent revision on taxonomy of any group should stand (supporting changes in taxonomy) but ignores this work if and when it is actually published.

  5. Tim Says:

    “I’m curious what the Amphicoelias “brontodiplodocus” specimens actually are. Any ideas from the SV-POW team?”

    Mickey took the words out of my mouth. Any takers?

  6. Tim Says:

    “Yeah, but would they have if no one had pointed out publicly that this was the case?!?”

    The PDF in this case is clearly formatted for printing (such as a booklet). For example, the first and last ‘pages’ are labelled as the front and back covers.

  7. Horridus Says:

    PR stunt?

  8. Mike Taylor Says:

    On printing hardcopies of the paper, Jerry asked: “Yeah, but would they have if no one had pointed out publicly that this was the case?!?”

    I think so, yes. We live in a very connected world, and the days are gone when something could just fade quietly away by being ignored. All the blogging that is surely going to happen around this paper would certainly have turned this idea up pretty soon.

    Mickey M. asked: “I’m curious what the Amphicoelias “brontodiplodocus” specimens actually are. Any ideas from the SV-POW team?”

    I know that Matt has more fully-formed ideas on this than I do, but I also know that the situation regarding his ideas is slightly delicate, so I’m not going to say any more, and I’ll leave it to him to say however much or little seems right to him. Sorry to be mysterious.

    Jaime mentioned: “It should be interesting if anyone argues that the most recent revision on taxonomy of any group should stand”. That’s what worries me: I know there’s a tendency on the Internet for people to assume that Whatever Was Published Most Recently Is The Real Truth.

    Thanks, by the way, to all who have commented so far.


  9. In response to Jaime, I think he’s being unfair about the illustrations. On the one hand I don’t want to be seen as defending these not-quite-valid papers again (after the Pickering fiasco), but it really seems to me that people are apt to declare them deficient in all areas without reflecting that tons of official papers are published all the time with far worse descriptions, illustrations, etc. without being lambasted over it. Sure the A. “brontodiplodocus” figures are worse than Taylor’s Giraffatitan, or Harris’ Suuwaasia, or Curry-Rogers’ Rapetosaurus paper. But those are all the cream of the crop. Compare it to what we normally get. Pulling out random files from my folder… Ampelosaurus illustrated a tooth and three vertebrae (with another view of one of the vertebrae, and a neural spine close up), Phuwiangosaurus had tiny drawings of five vertebrae and eight appendicular elements (with four additional drawings of different views), etc.. By all means insult the questionable taxonomy, ridiculous feeding hypothesis, and sloppiness and typos, but give credit where it’s due.

  10. LeeB Says:

    The authors seem to conclude that because all the specimens are found together they must represent a single species; yet present day herbivores often associate in multispecies herds.

    They also seem to hint in passing that Brachiosaurus and Camarasaurus could be male and female of one species.
    Hmmm.

    The specimens seem remarkable though, and if (when) they end up in museum(s) where they can be properly studied they could have much to say about lower morrison sauropods; and shed light on diplodocid inter and intra generic taxonomy.

    (Diplodocus seriously needs a species level revision).

    LeeB.

  11. Mike Taylor Says:

    LeeB — oh my, you’re right!

    “The morphological distances between Camarasaurus and Brachiosaurus are similar in many ways to what exists in the Dana sample, thus, the need to reconsidered these taxa as gender based.”

    Well that’s just … Hmm. What word is to morphology what “illiterate” is to language?

  12. Jamie Stearns Says:

    Reposted from my earlier post to the DML:

    Just my 2 cents worth, and coming from a complete amateur this doesn’t mean much, but either this is Apatosaurus (either excelsus or anunusually robust ajax) or my name is Pinky Gerbilhead.


  13. @Jaime: Well, keep in mind that there are two distinct ‘morphs’ being referred to this species. The type specimen is one of the more gracile ones, so it’s unlikely to be Apatosaurus. If the whole sexual dimorphism thing is wrong, there are at least two species and possibly genera in the mix.

  14. Henry Galiano Says:

    Mike – No apology necessary, in fact we are the ones that should apologize to everyone. Your comments are correct. In our defense, the Amphicoelias paper currently posted on the Dinosauria International website is obviously a drafted manuscript complete with typos, etc., and not a final paper. In fact, no printing or distribution has been attempted. This manuscript was temporarily placed on our website in response to inquiries from reporters interested in writing about the Dana dinosaurs – we thought it an easy way to provide them information – obviously that was a mistake – sorry! We never thought our draft was going to be so quickly discovered and electronically blasted throughout the paleontological community.

    Rest assured that we are not designating a type for A. brontodiplodocus until a recognized institution is found to house the specimen. The purpose of our research is to document, as best as possible, the only collection of complete diplodocid skeletons known, and we are very proud and excited to do so. These specimens represent a major contribution to sauropod paleontology, and hope all interested will agree. We stand behind our hypothesizes regarding the dimorphic nature of the sample which is crucial in better understanding sauropod taxonomy and biology, and hope, in the spirit of scientific investigation, our study will promote focused discussions in that direction.

  15. LeeB Says:

    Mike,

    I don’t think there is any word that bears the relationship to morphology that illiterate does to language.

    Perhaps a neologism such as amorphognostic is called for.

    LeeB.


  16. [...] The elephant in the living room: Amphicoelias brontodiplodocus [...]

  17. Jamie Stearns Says:

    Ah, my mistake. I was referring to the mounted specimen.

    The cervicals at the top of the page look more Diplodocus-like to me, and with this much variation the site looks more like a multi-species bonebed than anything else, something along the lines of the main Dinosaur National Monument quarry.

    This kind of mistake is a good example of why peer review needs to be part of the process for naming new taxa. Self-published material independent of review should not qualify as valid under whatever new rules get set up, and this is a clear example of why.

  18. Mike Taylor Says:

    Thanks, Henry, for this gracious response. It’s good to know that the manuscript, at least in its present form, is not intended to provide a scientific record. For the avoidance of doubt, it would be good if you were able to modify the version that is available online to include this disclaimer up front (taken from ICZN Article 8.2): “This work is not issued for public and permanent scientific record, or for purposes of zoological nomenclature.”

    We never thought our draft was going to be so quickly discovered and electronically blasted throughout the paleontological community.

    Well, it’s not 1995 any more :-) Or even 2009! We’re in the Shiny Digital Future, and anything interesting posted online will spread around the world very quickly.

    Rest assured that we are not designating a type for A. brontodiplodocus until a recognized institution is found to house the specimen.

    This is good news indeed.

    These specimens represent a major contribution to sauropod paleontology, and hope all interested will agree.

    No argument there!

  19. David Says:

    I’m tremendously relieved that these fossils will indeed be presented properly to the scientific community, and thanks to Henry for addressing this.

    Next time, maybe a good, concise, layman-appropriate press release will suffice?

  20. Bill Parker Says:

    “In our defense, the Amphicoelias paper currently posted on the Dinosauria International website is obviously a drafted manuscript complete with typos, etc., and not a final paper.”

    I’m not buying this explanation at all. The paper is clearly dated September 2010 and has a copyright statement with the date 2010. This would not be done on a “draft” copy awaiting revisions and for a “home” for the material to be found.

    Nice try but sorry.

  21. ech Says:

    ‘“brontodiplodocus” is a stupid name.’ – Yeah, but it’s not like the standards are very high in this area. /brontodiplodocus/ is not half as stupid as /problematicus/ or /Paraceratherium/. Is there a way to appeal these names? Can /nothing/ be done??

  22. Mike Taylor Says:

    ech: no, in general nothing can be done to change a zoological name once it’s been validly published (which, happily, brontodiplodocus has not). As regrettable as this may seem in some cases, it’s preferable to the chaos we’d have if names continually changed under our feet.

    There are a few exceptions in which specific kinds of small change can be made, but only corrections. The three cases that spring to mind are:

    1. If the etymology and other parts of the paper show that the name established is not what the author intended, then it can be amended to fit the original intention.

    2. If a species name does not match the gender of the genus to which it belongs, then it has to be changed to match — a monumentally stupid rule that causes wholly unnecessary additional confusion when species are moved between genera.

    3. The species names is malformed regarding plurals, then it can be changed, as in Seismosaurus halli which, because it was named after multiple Halls rather than a single one, was amended to S. hallorum.

  23. Anonymous Says:

    “They also seem to hint in passing that Brachiosaurus and Camarasaurus could be male and female of one species.
    Hmmm.”

    But then why are there four different variants of Camarasaurus (C. lentus, C. grandis, C. supremus, and C. lewsi at last count), and only one form of Brachiosaurus (B. altithorax). And if ‘camarasaurs’ represent the female form of Brachiosaurus, then why don’t we see any camarasaurs past the Late Jurassic? Shouldn’t we expect to find camarasaurs in association with Sauroposeidon and Abydosaurus if this were true.

    Question, if all the genera of diplodocid sauropods in the Morrison are considered congeneric, then wouldn’t the genus name be Dystrophaeus, not Amphicoelias. Dystrophaeus is thought to be a diplodocid sauropod, and it was named before Amphicoelias. And Dystrophaeus is known from the lowestmost part of the Morrison, which would mean Dystrophaeus viaemalae would be the senior synonym of Amphicoelias brontodiplodocus. Oh dear god that just makes it worse.

  24. Henry Galiano Says:

    Just to let everyone know ~ We have posted an updated version of our manuscript on our website reflecting changes concerning the non-designation of the holotype. Although the paper has still not been completed, no changes have been made altering it conclusions. Interestingly, despite the 4000 recent hits and downloads from our website, it is surprising no evidence has been submitted challenging our claims.

  25. David Says:

    “Interestingly, despite the 4000 recent hits and downloads from our website, it is surprising no evidence has been submitted challenging our claims.”

    What’s so surprising about that? Where would that evidence be submitted? On a blog? On the DML? Tom Holtz sent out the link to it two days ago. I imagine folks are waiting for the publication of this material.

    I’ll say it again: This all could have been avoided with a simple press release.

  26. Henry Galiano Says:

    Regarding Dystrophaeus viaemalae, we originally wanted to use this name but felt that the type material was too fragmentary and could not be distinguished adequately. Also there was some doubt whether the type locality was indeed part of the Morrison Formation.

  27. Heinrich Mallison Says:

    Good to hear that this was not intended as a scientific publication in the state it is in now.

    As far as the content goes: a load of bulls***!

    I took a 3 minute glance at it and found five whopping mistakes. No, let me re-state: 5 total catastrophes! Given that I read only the figure captions and maybe five more sentences, that is a quote of ~80% BS!

    Henry, you want evidence you f-ed up? Here goes:

    - “Except for size and robustness these elements virtually the same” from caption of Fig. 30. Now please go an look at the limbs of extant bovids. GO! You’ll find that there are genera from different continents having limbs more similar (and sometimes of the same size to boot) to each other.

    - Fig. 33, position of the scapula on the ribcage. Utter nonsense – please take a pen and draw in the major muscles of the pectoral girdle. Then come back and explain to us how this position allows the shoulder to take any weight.

    - Abstract: “Graviportal limbs with digitigrade feet indicate that Amphicoelias was capable of long distance travel. A hyper-extended neck along with filter feeding capabilities supports the suggestion that a wading habit was their principal ecological niche.” Take a look at these feet and compare to all extant animals that wade. Then come back and explain how the sauropods in general avoided getting stuck in the mud like a kid stupid enough to walk on stilts into the village pond. You’re quite right, derived sauropods were cursorial. But they were most certainly extremely maladapted for soft ground.

    - And don’t get me started about the filter-feeding. Instead, check out the wear factes on the teeth of diplodocines. You won’t find any food in water that matches them.

    ’nuff said.

    Oh, no, wait one, another whopper, one that *really* irates me:
    - Fig. 10 A and B: supposedly, the cervical verts of your DQ-TY are show “proportional similarity” to D. carnegii. However, the dorsal processes are WAY different. Hey, what a surprise: different genera do not differ in ALL character, only in SOME. DOH!

  28. bruce Says:

    I’m so glad the SVPOW picked this up. My first instinct yesterday was to insist this be addressed on this forum. I’m not disappointed!

    >>>”Interestingly, despite the 4000 recent hits and downloads from our website, it is surprising no evidence has been submitted challenging our claims.”

    Persons practicing real science must wait for their dropped jaws to re-clench before responding, and then chuckling takes over. The potential to actually have to legitimately (peer review) and taxonomically (ugh) clean up this mess is mind-boggling. A well done refutation would require much more than its value to construct.

    These are fantastic specimens. There is no question that they have been expertly unearthed, prepared, and illustrated.

    It’s really a shame that certain specimens like these weren’t some of the original Cope/Marsh holotypes – but I guess the crappy, inadequate holotypes adds up to a lot of fun scientific inquiry.

    Having the taxonomic/ecological legacy of Morrison sauropods uprooted by a sloppy hand is insulting and potentially could do great scientific harm.

    To suggest that the .pdf on the website was not intended to complete and polished is utter hog-wash.

    If one chooses to practice commercial paleontology, at least respect the ethics of the scientific method, if not scientifically priceless specimens such as these.

    Bruce


  29. [...] de la nueva especie ha sido fría y ha pasado más bien desapercibida. No obstante en el blog Sauropod Vertebra Picture of the Week el autor ha sido muy crítico con la “fagocitación” de géneros propuesta en el [...]


  30. [...] to write about this, partly because it’s so darn depressing, but mostly because in the wake of this comment it seemed like the “Amphicoelias brontodiplodocus” paper was being withdrawn, and to [...]


  31. [...] Sauropod fans will probably be regular readers of SV-POW! and might have spotted the recent posts here and here on the sort-of-but-not-quite paper by a group working on some privately collected [...]


  32. [...] SVPOW Mike Taylor and Matt Wedel have invalidated A. brontodiplodocus. They discussed in this post that it has not been validly published on paper. Actually, they didn’t even mean to publish [...]

  33. Bill Parker Says:

    “Regarding Dystrophaeus viaemalae, we originally wanted to use this name but felt that the type material was too fragmentary and could not be distinguished adequately. Also there was some doubt whether the type locality was indeed part of the Morrison Formation.”

    My understanding is that the rest of the skeleton is still in a cliff in Utah. I also understand that it is nearly impossible to collect. Maybe someone should give it a shot.

  34. Kevein Winberry Says:

    Despite the sloppy and incomplete nature of this paper, it does succeed in at least attempting to address a number of neglected issues concerning the sauropods of the Morrison formation. To date there are currently 21 (maybe more) different sauropod species described within the Morrison, a period spanning roughly 7 million years. The taxonomic validity of a majority of these animals, the diplodocidae in particular, rests on one or more largely incomplete specimens being compared to still further incomplete material. Therefore creating a very confusing situation to say the least. The factors described in this paper such as ontogeny, natural variation, and sexual dimorphism were never taken into consideration upon the naming of these animals. Also, at this time the number of scientifically useful specimens in institutions are far too few to provide an accurate population sample from which to make definitive conclusions concerning these factors. It is glaringly obvious that synonymy, at some level, is desperately needed, and of which there has been much apprehension to attempt. However, it is sites like this one that will bring us closer to achieving that and help our understanding of both the morphological and taxonomic relationships of these animals. In regard to this paper, although it falls short in format, it dares to “stir the waters” around topics of which many have sheepishly tip-toed around. And in that respect, for the science of vertebrate paleontology there is nothing better.

  35. Mike Taylor Says:

    Kevein Winberry postulates:

    The factors described in this paper such as ontogeny, natural variation, and sexual dimorphism were never taken into consideration upon the naming of these animals [i.e. the numerous diplodocid species].

    That’s not really true. For example, Riggs’s (1903) synonymisation of Brontosaurus with Apatosaurus was based on recognition that the latter was the adult of the former; and the idea that Diplodocus and Barosaurus represent sexual dimorphs of a single taxon has been considered and rejected. The truth is that the current taxonomic consensus of Morrison Formation sauropods is just that, the consensus that has emerged from more than a century of mostly careful work, which along the way has absorbed proposal and counter-proposal, and which has certainly not been as oblivious to ontogeny and sexual dimorphism as you seem to imply here.

    Of course that doesn’t necessarily mean that the current consensus is correct; but it does mean that, as the output of the work of numerous dedicated, diligent palaeontologists, it’s worthy of some respect. If it’s going to be overturned, then that will only be because an alternative hypothesis is shown to be extremely well supported. Fishing expeditions aren’t going to cut it.


  36. [...] may remember that when I wrote about Amphicoelias diplobrontobarowassea the other day, I rather ungraciously complained that “I don’t want to talk about that.  There are other [...]

  37. LeeB Says:

    There would be a consensus at the genus level for Morrison sauropods; and at the species level for Camarasaurus and Apatosaurus but nobody seems sure if D. longus, D. carnegii and D. hallorum are one species or more than one; and if D. hayi is different enough to belong in a separate genus.
    And also whether Diplodocus and Amphicoelias altus are congeneric.
    There are good Diplodocus specimens such as the Poison Creek material which are not assigned to a species because of these problems; also abundant material fron the Howe quarry where there has been uncertainty whether it belongs to Diplodocus or Barosaurus.
    A cladistic study of all the more complete Diplodocus specimens and including Barosaurus specimens and perhaps Tornieria and Suuwassea as outgroups may throw up surprises, as the study at specimen level did for Apatosaurus.

    Hopefully when these new “Brontodiplodocus” specimens reach a museum and can be studied they will trigger this kind of revision of Diplodocus.

    LeeB.

  38. Mike Taylor Says:

    It’s true that there is plenty of quibbling over the details of sauropod phylogeny, especially once you get down to the species level. Among the multispecific Morrison sauropods, only Apatosaurus (thanks to Upchurch et al. 2005) has been looked at with any phylogenetic rigour, and it would indeed be good to see something simialer done for Diplodocus, and indeed Camarasaurus which I am convinced is overlumped. Still, all of this is minor stuff in the scheme of things. Throwing it all away by lumping everything into a single species really wouldn’t get us anywhere worth being: it would leave not only unresolved but unaddressed the real question, that of the phylogeny within that clade. That question remains whether you call the clade a species or a family.

  39. LeeB Says:

    Given the length of time covered by the morrison I wouldn’t be surprised to find that there were several Diplodocus species present; but it would be nice to know what species were actually there, their time ranges, phylogeny and geographic distribution.

    And for a total change of topic I see in the latest National Geographic that an organisation called CyArk have been using a 3-D laser scanner and surveying equipment to make high resolution scans of archaeological landmarks.
    I wonder if such equipment could be used to quickly scan a mounted sauropod skeleton in a museum in its entirety, enabling one to get it’s measurements without having to climb all over it.

    LeeB.


  40. [...] that displeases paleontologists such as Michael Taylor of University College London, who noted on a “Sauropod Vertebra Picture of the Week” blog (yes, there is a blog for everything) that the Society of Vertebrate Paleontology discourages [...]

  41. Tim Says:

    Mike – I agree with you here. Camarasaurus may well be overlumped. I vaguely recall that Cathetosaurus has some titanosauriform features not seen in Camarasaurus, but Cathetosaurus is typically regarded as a species of Camarasaurus.

    There is a quite a lot of theropod genera/species in the Morrison too.


  42. [...] the way is not over yet), and then in the festival of articular cartilage, then by the whole “Amphicoelias brontodiplodocus” thing and the subsequent discussion of amateurs in palaeo, and then by what [...]

  43. Adam Baig Says:

    I am not a professional paleontologist, but I certainly feel that I know a lot about dinosaurs for I had researched them amateurly for twenty years. Anyway, in what is now North America in the late-Jurassic, with so many “diplodocid” genera and so many more “diplodocid” species named and described, which all lived in the same continental region and time, just never made sense to me. This is not the same as concluding that a fossil lion, a fossil cheetah and a fossil domestic cat can be considered to be one and the same because to sauropod standards, these animals are small. These sauropods, as we all know, were gigantic. Really, how many sauropod genera and species could exist in the same time in the same continental region, with enough food and roaming space for everybody? It just does not make sense. Also, with modern-day crocodiles (the dinosaus’ closet non-avian relatives), there is noticeable size variation between males and females. It makes perfect sense that the discovered big-and-bulky and the long-and-slender finds were male and female representatives, when they were once considered different genera. We already know that sauropod dinosaurs had more complex behavior and lifestyle than preivously thought (like herding). It makes perfect sense that there would be noticealby morphological differences between male and female sauropods as well, since there would be needs to compete for mating rights. We also need to consider that there are always going to be age differences in which very elderly individuals are going to be very large because they would continue to grow after reaching maturity, though a lot slower. (This is already known in elderly crocodiles today, and already found in other sauropods, like “Seismosaurus” as not being a new genus and species but as a very elderly already-described “diplodocid”). Individual variation would be very high for a large sauropod in general. I heard someone say that today, we have conspecific herds, and I know this too (such as very large herds of zebras mixed in with blue wildebeest in Africa); but again with the sauropods’ immense size, there would be not much room and food availability for very large herds so that more species can roam together. So, to conclude, it is very reasonable that there was only one double-beamed sauropod species in what is now North America in the late-Jurassic. Yes, the “Amphicoelias brontodiplodocus” was not the only sauropod at that time becuase there was also i.e. “Brachiosaurus”, etc; but considering its size and its need for a lot of food and space, once again, this makes perfect sense.

  44. Mike Taylor Says:

    Adam: “it makes perfect sense that” is not a scientific argument. As we’ve already pointed out here, anyone seriously advancing the hypothesis that there was just one diplodocid species in the Morrison has to come up with an explicit and persuasive accounting for (A) the HUGE range of morphological variation; (B) the stratigraphic separation between species within the Morrison; (C) the geographical separation ditto. No-one has come close to doing that, in fact no has even attempted it.

    So, no. There were multiple diplodocid species in the Morrison. Lots of them. Whether you think that makes sense or not.

  45. Adam Baig Says:

    Mike Taylor,

    Hello. I did not think that an amateur like me was going to be heard. So, I thank you for taking the time to read what I had to say.

    Okay, I agree that there would have to be more substantial evidence, such as a much larger range of individual variation to advance the hypothesis that there was only one double-beamed sauropod in what is now North America in the late-Jurassic, despite that the sauropods were very large and that they need lots of food and roaming space (as if I had to say that part).

    However, do you agree that there would be noticeable differentiation in, say, sexes in the double-beamed sauropods, like how we know and can see a male and female “Crocodylus porosus” from far away, in the sense that there is enough dimorphism to tell them apart easily? Since we know that sauropods’ lifestyles were more complex than previously thought, I would seriouly consider that there would be “bulls” and “cows” in sauropods with noticeably different lifestyles particular during copulation-season, like how it is with many large reptiles and mammals today. Thus, would there be dimporphism to easily tell a male and female double-beamed sauropod from far away too, indicating that what was once deemed by us as two species that looked noticeably different from each other, were actually two sexes of the same species?

    Also, so genera like “Apatosaurus”, “Diplodocus”, “Barosaurus”, etc. are still valid genera (and with them, their type species). However, please help me out here. To me, it seems like almost every newly uncovered fossil seems to “get” a new specific name, despite establishement in an existing genus. Though, like with “Seismosaurus” being a very elderly individual of a “Diplodocus” species, would there still be a lot of individual variation in a double-beamed sauropod species so that we could not automatically consider so many different species of a “genus” in a large-sized animal? This happened with “Triceratops”. For instance, would there be enough individual variation to validly hypothesize that “Diplodocus longus”, “Diplodocus carnegeii”, “Diplodocus hallorum” and “Diplodocus hayi” all living in the same geographic location and the same timeframe be actually the same species, based on individual variation of sex and age? Yes, we all do not have enough evidence to support this, but we know that sauropods could roam for long distances, covering a lot of ground.

    Okay to conclude, saying that it “makes sense” or not is certainly not substantial to support a claim; and there were certainly more than one double-beamed sauropod species in this respect, despite their similar timeframes and geographic location as well as their immense sizes and their need for lots of food and roaming space. However, like what happened with “Triceratops”, I do not believe that there could have been so many species at the same time in the same location. I would say that there were several diplodocids, but not many. I know that I am an amateur, but I do not consider myself as one who cannot theorize in this.

  46. Matt Wedel Says:

    For instance, would there be enough individual variation to validly hypothesize that “Diplodocus longus”, “Diplodocus carnegeii”, “Diplodocus hallorum” and “Diplodocus hayi” all living in the same geographic location and the same timeframe be actually the same species, based on individual variation of sex and age?

    Who knows? The point is that all of those species of Diplodocus did not live in the same geographic location or the same time frame. The Morrison is not just one big hole in the ground. It’s not even like the Serengeti. Because when I say “Serengeti”, we all think about all of the critters that we’ve seen in documentaries. But when I say, “Morrison”, what I approximately mean is “all of the fluvial and lacustrine deposits of the entire western US covering more than 5 million years.” So if you have a hard time believing that all of these animals were living in the same place at the same time, no wonder. They weren’t. The quarries we know them from are separated by hundreds or even thousands of miles–from New Mexico to Canada!–and by immense spans of time. So a better comparison wouldn’t be to the Serengeti (which I acknowledge is a bit of a straw man brought into the argument by me, not you, but just roll with it), it would be to all of sub-Saharan Africa since the beginning of the Pliocene until now. That diversity completely swamps the diversity of things that are alive today in the same biogeographic region. But we don’t have a problem with that, because (a) most of us are unfamiliar with the Plio-Pleistocene faunas of Africa, and (b) people who are familiar with them are conversant with the vast (in human terms) time frames involved. OTOH, I think it’s easier when thinking about the Morrison to slip into a lazy way of thinking about it as one big contemporaneous floodplain. It wasn’t.

    However, like what happened with “Triceratops”, I do not believe that there could have been so many species at the same time in the same location.

    Again–all of these species did not live at the same time, or in the same location. My guess is that there was rarely more than one species of each genus in any particular place at once. Brian Curtice has quipped that species names for Morrison sauropods are basically quarry markers. There’s a lot of truth to that. But there is also some biological truth, as well, because these quarries are widely separated in space and time, and the animals that we pull out of them are usually diagosably distinct from their congeners in other quarries. So I’m not sure what you mean by “what happened to Triceratops“. If you mean, a bunch of genera should get collapsed into a few, then cheer up, that happened about a century ago with the sinking of Atlantosaurus, Morosaurus, and so on. If you mean that the existing genera of sauropods are going to get further collapsed because they’re all just growth stages or sexual dimorphs, as has been suggested for Torosaurus, forget it. The differences between Apatosaurus, Barosaurus, Diplodocus, and Suuwassea are too big, too numerous, too constant across time and space and through development. There are baby Apatos and Diplos and Baros, and they clearly belong to those respective genera, and the differences between the genera are not consistent with sexual dimorphism (different vertebral counts, features of the braincase, etc.).

    I am not a professional paleontologist, but I certainly feel that I know a lot about dinosaurs for I had researched them amateurly for twenty years.

    We welcome comments from everyone; we were all amateurs once. But if you’re trying to come to terms with the idea that a lot of big animals lived together in one place, simply reading more about dinosaurs probably isn’t going to help. Digging into the ecological literature on niche partitioning and looking at the evolution of African bovids since the Pliocene…well, that might not help either, since the Morrison sauropod boom is a genuinely hard, weird problem, but doing those things would at least arm you with the tools and the knowledge for thinking about these kinds of problems. Also, seriously, get John Foster’s book Jurassic West. Just do it. You’ll learn a ton, and it’s something you’ll refer back to a LOT.

  47. Adam Baig Says:

    Hello Matt Wedel,

    That was quite a thorough explanation, and THAT made a lot of sense too. What got me is when you mentioned the fact that we have seen baby dinosaurs of the different diplodocid genera, and the fact that they were already distinct. If they were all the same species, then they would have all looked the same as babies, and then matured later to attain sexual dimporishm. This could not be, although there were still cows and bulls in the diplodocid genera and species, which I have to say were dimorphic due to the sauropods’ more complex lifestyle. Also, your mentioning of different vertebral counts and different crainial structures did shed more light on the fact that there were many diplodocid genera in what is now North America in the late-Jurassic. I now postulate that the “Apatosaurus” and “Diplodocus” found together may just have been a simple crossing-of-paths by two different sauropod herds, when some unfortunate disaster struck.

    I still do not believe and cannot comprehend that there were so many species for an individual North American late-Jurassic sauropod genus, like the case with “Diplodocus” because sauropods could roam for long distances within the continent, and with fewer species (though with many genera), they could last for at least several millions of years with plenty of food and roaming space for everybody for a while. However, I now rebelieve that “Apatosaurus”, “Diplodocus”, “Supersaurus”, “Barosaurus” and “Suwassea” were distinct and valid after all.

    Matt, thank you for your time to help a “lowly” amateur like me. Again, you were very thorough in your explanation.

  48. Ken Johnson Says:

    The differences between Apatosaurus, Barosaurus, Diplodocus, and Suuwassea are too big, too numerous, too constant across time and space and through development.

    I’m having some trouble making sense of this, perhaps you guys can help me out. While flipping through the pages of the book “THE DINOSAURIA” I was startled by how little material there is assigned to each species. Diplodocus for example: D.longus-2 skulls, caudal series, D.carnegii-5skeletons without skull or manus, 2 skulls, numerous postcranial elements, D.hayi- a single partial skeleton, D.lacustris- just a dentary with teeth.
    This is admittedly alot of material in comparison to other members of the sauropoda, but only comparatively.(The numbers behind the genera Apatosaurus and Barosaurus don’t fair much better) From a biological perspective, I find it hard to believe that a range of natural variation can be confidently established for any animal, extant or extinct, on the basis of less then 6 specimens to each species. At the very least not with the confidence that is implied here. This would hold true for variation due to ontogeny and sexual dimorphism as well. There does not seem to be enough “complete” material to set such concrete boundaries between what constitutes a distinct species and what is a variant of age or gender.
    I also took you up on your recommendation of “Jurassic West” by John Foster, really an excellent book. In his analysis of Diplodocus he states: “Most of the differences between D.carnegii and D.longus are minor and likely due to individual variation, and thus the validity D.carnegii as a name is questionable. There may well be just one well-known species of Diplodocus represented in the Morrison Formation.”p191 I am in full agreement with this. With the “limited” number of specimens currently available this very well may be the case regarding Diplodocus. On this premise, both Apatosaurus and Barosaurus would appear be in the “same boat” so to speak.
    As an aspiring paleontologist I would greatly appreciate feedback as to where I may have gone astray in my thinking.

  49. Mike Taylor Says:

    Hi, Ken. Excellent question. So good that, rather than try to answer it here, I’m going to do a followup post on this subject. Stay tuned!


  50. [...] the use of privately held specimens and the use of a non-peer-reviewed “publication”. Mike Taylor and Matt Wedel led a detailed discussion about the flaws in this paper at SV-POW. In the [...]


  51. [...] literature, basic biomechanics, taxonomy, and so forth. See Mike Taylor’s reaction on SV-POW! here. There seems to be an updated version (and who would UPDATE a published paper?), but I [...]


  52. [...] initiative and subsequent cavalier treatment of Morrison sauropods — maybe even by the Amphidocobrontowaassea paper. Folks, there is no intrinsic merit in assuming less diversity. Historically, the Victorian [...]

  53. Rexisto Says:

    The skull of Kaatedocus, reminds me to Amphicoelias brontodiplodocus, me or would it genera?


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