Supersaurus, Ultrasaurus and Dystylosaurus in 2019, part 4: what is the holotype of Supersaurus?

June 22, 2019

Before we get on to the home stretch of this series — which is turning out waaay longer than I expected it to be, and which I guess should really have been a paper instead — we need to resolve an important detail. We all know there are two scapulocoracoids in the BYU Supersaurus material, and that one of them is the holotype: but which one?

The two elements

Since we don’t know the actual specimen numbers yet, we’ll refer to the two specimens as Scap A and Scap B for now.

Both specimens are on loan from BYU to other museums. We’re not sure where Scap A is, but there is a good cast at the Dinosaur Journey Paleontological Museum in Fruita, Colorado; and Scap B is at the North American Museum of Ancient Life (NAMAL) in Lehi, Utah. Happily, we saw both on the Sauropopcalypse. Unhappily, we were in a rush both times, and didn’t pay them anything like the attention they deserve.

Scap A

We don’t have many photos of this, because we only had a single day at Dinosaur Journey museum and we had a lot of specimens we wanted to hit in collections. But it’s still shameful that we have as little as we do. Here’s one from Matt’s earlier visit in 2014:

Cast of one of the scapulocoracoids of Supersaurus, which we here refer to as Scap A, at the Dinosaur Journey musuem in Fruita, Colorado. Matt Wedel for scale.

And here is an anaglyph made from the only two photos I took on our 2016 Sauropocalypse visit:

Sort-of-OK anaglyph of the cast of the Supersaurus scapulocoracoid A. It’s not great because we don’t have a good pair of source photos, but it’s still way more informative than a 2d photograph.

If you think our images are disappointing, check out Jensen’s own illustrations of this specimen. It crops up in line-drawing form as part B of figure 8 in his 1985 paper:

Jensen 1985:figure 8B and G. For comparison only, not to scale. Profiles of various sauropod scapulae and scapulocoracoidae. B, Supersaurus vivianae, first specimen. G, Supersaurus vivianae, second specimen. (Other, non-Supersaurus, parts removed.)

And that seems to be all we have of this specimen.

Well … almost all. There is just one other photo …

I really really wish I’d spent less time making out with this specimen and more time studying it. There’s a lesson there for all of us, kids!

This scap has really nice, clear ridges running along the ventral border of the proximal end, and up from there to the acromion process. That makes it very clear that we’re looking at the lateral side of the scap, which means it’s a left scapulocoracoid.

By the way, I am a little short of six feet tall. Using myself as a very crude scalebar, it looks like this scap is a hair over eight feet long. (Why am I using Imperial measurements? Because, as will become clear below, that’s what Jensen used, and so what we want to compare with.)

Scap B

This occurs in Jensen’s (1985:figure 8G) line drawing, as shown above. But there are a few more photos out there. For a start, this is the scap which Jensen is measuring and then lying next to in the photos in his descriptive paper:

Jensen 1985:figure 6. A, Measuring Supersaurus vivinae scapulocoracoid. D. E., Vivian Jones; J. A. Jensen. B, The author, 6’3″ tall beside Supersaurus vivianae scapulocoracoid.

This is evidently the scap that we photographed at NAMAL, although it’s been flipped since the photos were taken of it in the ground:

Supersaurus vivianae scapulocoracoid, photographed at the North American Museum of Natural Life. The exhibit text reads: “Supersaurus scapula and coracoid. This is the actual Supersaurus bone that the world saw when the announcement was made of the new animal’s discovery in 1972. The scapula lay in the ground for five more years, waiting for the collection of other fossils that lay in the path of excavation. The flatness of the bone presented a challenge to “Dinosaur Jim” Jensen, who had to figure out a way to get the bone safely out of the ground. He finally accomplished this by cutting the scapula into three pieces. In 1988, Cliff Miles, Brian Versey and Clark Miles prepared the bone for study. It is still one of the largest dinosaur bones known in the world. Specimen on load from Brigham Young University’s Earth Science Museum. Late Jurassic/Early Cretaceous (about 144 million years ago)

A similar photo turns up in Lovelace et al.’s (2008) description of the WDC Supersarus specimen, where a specimen number is given. This is welcome, as neither museum display includes a specimen number, and none of the Jensen’s illustrations do, either. It’s the first specimen number we’ve seen in this post.

Lovelace et al. 2008:figure 10. Lateral view of Supersaurus right scapulacoracoid (BYU 9025).

Also, Lovelace et al. (2008) provided a scalebar. If it’s reliable — which is always open to question with scalebars — the scapulocoracoid is 2.34 m long (based on 687 pixels for the scap, 147 for the scalebar), which is about 7’8″.

I don’t know where Lovelace et al. got the specimen number for this element: it’s certainly not on display in the NAMAL public gallery. Elsewhere, Lovelace et al. (2008:527) say that “The name Supersaurus was erected for a single scapulocoracoid, BYU 12962″, contradicting Jensen’s designation of BYU 5500 (i.e. BYU 9025) as the holotype.

Is this in fact a right scapulocoracoid, as claimed? I did wonder, because based on my own photos and the Lovelace et al. illustration the surface we’re looking at is pretty flat and featureless, which would suggest it’s the medial side of the bone. If that were so, it would be a left scap viewed from inside, not a right scap viewed from outside. But I was able to recover a very rough-and-ready anagylph from my NAMAL photos, and that was enough to persuade me that there is some surface structure on this bone, and that we are indeed therefore looking at the lateral face of a right scap.

(If you can’t make out the 3d structure here, it’s because you don’t have any red-cyan anaglyph glasses. Get some red-cyan anaglyph glasses. You’ll thank me.)

Anyway: I am satisfied that Scap A is a left scapulocoracoid and Scap B is right scapulocoracoid. So that’s something.

Which is the holotype?

This should be a simple question to resolve. But it’s not, for several reasons. First, although the earliest literature on Supersaurus refers to the scapulocoracoids, it doesn’t give specimen numbers. Second, Jensen’s (1985) description is vague about specimen numbers, sometimes using them and sometimes just referring to “first specimen” and “second specimen”. Third, the specimen numbers that Jensen used have since been changed. Fourth, the subsequent literature contains contradictions and perhaps straight-up mistakes. And finally, as though all that were not enough — and as we’ve already noted — the two museums that have the actual bones on display have omitted specimen numbers from their signage.

Yeah. It’s pretty crazy stuff. Let’s see if we can sort it out.

That Reader’s Digest article

The earliest reference to the name “Supersaurus” we’ve been able to find in the literature is George 1973a, which was subsequently condensed into George 1973b in Reader’s Digest. (These both predate George 1973c, cited by Curtice and Stadtman 2001, which I have been unable to obtain a copy of, if indeed it is actually a real article, as it does not seem to be.)

Aaanyway, here’s what George (1973b) says about “Supersaurus” scapulae. It doesn’t amount to much.

A shoulder blade, still partially encased in clay, spanned eight feet. Breaks and cracks were sealed with a mixture of sand and plaster, the bones were wrapped in burlap soaked with plaster of paris, braced, then swung aboard a special trailer for the journey to B.Y.U. in Provo, Utah. There, “Supersaurus,” as we shall call him, awaits an official name and taxonomic classification.

This certainly sounds like the eight-foot-long scap was destined to be the type specmen, but it doesn’t come out and say it.

Jensen 1985

As far as I know, the next published reference to this material is eight full years later, in Jensen’s (1985) formal description. It needs careful reading. But what seems clear (from page 701) is:

HOLOTYPE.—BYU 5500, scapulocoracoid 2.44m (8′) long.

REFERRED MATERIAL.—BYU 5501, scapulocoracoid 2.70 m (8′ 10″) long. [And other material not of interest for our purposes.]

[… and a little later …]

DESCRIPTION.—(Holotype BYU 5500; right scapulocoracoid) Scapula long but not robust; distal end expanding moderately; shaft not severely constricted in midsection. [There is more, but it’s not relevant here]

REFERRED MATERIAL.—BYU 5501, scapulocoracoid 2.70 m (8′ 10″) long. Description same as Holotype, BYU 5500.

So based on this, the “description” of the two scaps is the same, and the only recognised difference is in length: the holotype, at eight feet in length, is ten inches shorter than the referred element.

On that basis, Scap B might seem the more likely contender to be the holotype, as the scalebar in Lovelace et al. 2008:figure 10 suggests a length of 2.33 m which is closer to the 2.44 m given for the type than to the 2.7 m given for the referred specimen.

(On the other hand, the photo of me in love with Scap A at Dinosaur Journal suggests it’s about eight feet long, which would mean that it might be the type. *sigh*)

As we have seen, the captions in Jensen 1985 do not give specimen numbers, so we can’t tell whether the scap in his figure 6 is the holotype. And in the comparative figure 8 which shows both scaps, he maddeningly calls them “first specimen” and “second specimen” instead of giving numbers. We might guess that “first specimen” is the type; but it might instead refer to the order in which they were found or excavated. And we might guess that the specimen appearing in Jensen’s photos is the type, but it really would only be a guess — and one contradicted by the guess based on “first specimen”, since the photographed bone is the “second specimen”.

Jensen 1987

Jensen’s 1987 paper is primarily about brachiosaur material, but it does contain information relevant to to the present problem. Its figure 9 replicates Jensen 1985:figure 8 (the comparaive scapula line-drawings) but with an even less informative caption that doesn’t even say “first specimen” or “second specimen” for the two Supersaurus scaps. But then the text on page 602 may contain a key bit of information, given away in passing as though by accident:

I here remove the vertebra, BYU 5003, from Brachiosauridae and provisionally refer it to the Diplodocidae. This referral is based on two factors: principally, a bifurcate neural spine, and, secondly, the fact that two unusually large scapulocoracoids (Figs. 9B, 9G), found in the same (Dry Mesa) quarry, were referable to the Diplodocidae. One of these (BYU 5500, Fig. 9B) is the holotype of Supersaurus vivianae Jensen (1985).

Astonishingly, this is the first time in any of Jensen’s papers that he associates a specimen number with an illustration of either of the Supersaurus scaps. Jensen was notoriously careless with specimen numbers, but BYU 5500 does match his designation of the holotype in his 1985 paper, so we can perhaps be somewhat confident in this case.

The old specimen number BYU 5500 corresponds with the new number BYU 9025, which suggests that BYU 9025 is the the scap illustrated in Jensen 1987:figure 9B — which is scap A.

Curtice and Stadtman 2001

Curtice et al.’s (1996) paper referring the Ultrasauros holotype dorsal vertebra to Supersaurus does not say anything about the two Supersaurus scapulae. But the followup paper on Dystylosaurus (Curtice and Stadtman 2001) does. As noted in part 3 of this series, the “Supersaurus vivianae roll call” section remarks:

When [Supersaurus was] formally described (Jensen, 1985) a number of elements were referred to the holotype including the left scapulocoracoid discovered in 1972 (BYU 9025), a right scapulocoracoid (BYU 12962) …

This is not as helpful as it could be, as it lists both scapulae as “referred” without stating explicitly which was the holotype. But based on the evidence so far, we can be fairly confident that it it really was BYU 9025 (BYU 5500 of Jensen’s usage). The really useful information here is the designation that 9025 is a left scap and 12962 is the right. Since scap A is clearly left sided, this offers corroboration that is is the holotype, BYU 9025.

As we discussed before, Curtice and Stadtman (2001:39) went on to say:

Jensen never referred the two Supersaurus scapulocoracoids to the same individual due to a 260 mm discrepancy in length. Stripping away the paint and resin on BYU 9025 revealed the proximal end had been inadvertently lengthened during preservation. Close examination of the actual bone surface nets a total scapulocoracoid length less than 50 mm longer than BYU 12962, an amount easily accounted for by scapular variation and thus here both are referred to the same individual.

But this doesn’t make sense for two reasons. Most importantly, BYU 9025 is BYU 5500 of Jensen’s usage, and his 1985 paper makes it clear that this was the shorter of the two scaps at 8 feet, compared with 8 feet 10 inches for his BYU 5501 (i.e. BYU 12962). Shortening BYU 9025 would increase the discrepancy in length between the two scaps, not decrease it. Perhaps Curtice and Stadtman got the two scapulocoracoids’ specimen numbers reversed?

It’s also surprising because of the claim that the it was the proximal end that was inadvertently lengthened. The proximal end of a scapulocoracoid is the coracoid bone, which is thick and sturdy, and has a well defined proximal margin that would be difficult to inadvertently lengthen. Whereas the distal end — the farthest part of the scapula blade — is thinner and easily broken, and potentially shades into cartilage where the cartilaginous suprascapula attached. We could easily imagine the latter being subject to interpretation, but not really the proximal end. Perhaps Curtice and Stadtman (2001) were using the terms “proximal” and “distal” in the opposite sense to how they are generall applied to scapulae?

Dale McInnes’s involvement in preparation

In a comment on the first post in this series, Dale McInnes took issue with aspects of Curtice and Stadtman’s account of the repreparation of the scaps. According to McInnes, Jensen sent “the second specimen” (i.e. what we’re calling Scap B, if the caption to Jensen 1985:figure 9 is to be trusted) to RAM, and Phil Currie had McInnes prepare it in the late 1970s (i.e. after the initial popular publications on “Supersaurus” but well before Jensen’s formal publication in 1985). In an 11-foot-long field jacket, they found 9’2 of bone, which they reduced to 8’10 by closing four inches of open cracks.

So far, this account is consistent with that of Jensen (1985), who quotes only the final prepared length of 8’10”. But it doesn’t help us to make sense of Curtice and Stadtman’s account of re-preparing BYU 9025 to reduce its length, thereby creating a larger gap between its length and that of BYU 12962.

If Curtice and Stadtman were here reporting on the wrong scapula (i.e. they “stripped away the paint and resin” from BYU 12962) then it seems they may have undone some of the careful work done by McInnes and colleagues to preserve “an area that had an ultra thin section that at best could only be described as a sharply defined delineation of the distal termination (literally powdered bone) [which might have been] an imprint of the cartilage”. If so, that is unfortunate indeed.

So which is which?

Jensen 1985 designated BYU 5500 (= BYU 9025) as the holotype and said it was 2.44 m (8′) long. He referred BYU 5501 (= BYU 12962) and said it was 8’10” long — but neither scap in its present form seems to be longer than 8′, so the differences in length reported by Jensen don’t help much.

Scap A (at the Dinosaur Journey Paleontological Museum in Fruita, Colorado) is a left scapulocoracoid. Curtice and Stadtman (2001) noted that BYU 9025 is a left scap (and BYU 12962 is a right scap), so that suggests that Scap A is BYU 9025.

Scap B (at the North American Museum of Ancient Life in Lehi, Utah) is a right scapulocoracoid, maybe 2.34 m long (7 feet 8 inches), based on the scale bar from Lovelace et al. (2008:figure 10). Their caption for that figure says it’s BYU 9025, but elsewhere they claim (incorrectly as far as I can tell) that BYU 12962 is the holotype, so something is wrong there.

The single most helpful thing in the literature is Jensen’s (1987:602) almost parenthetical comment that “(BYU 5500, Fig. 9B) is the holotype of Supersaurus vivianae“, as it’s the only published work that ties any specimen number to any illustration. Figure 9b shows Scap A — which indeed seems to be about eight feet long, according to the very fallible Mike-as-scalebar method.

But Curtice and Stadtman’s (2001:39) comments on re-prepping BYU 9025 suggest that it is the longer of the two elements, and  therefore (according to Jensen’s 1985 description) the referred element and not the holotype. We know that one of the scaps at least at one time measured 8’10, becausde of McInnes’s account of reducing the length of “the second specimen” to 8’10. But neither of them presently seems to be that long. (I hope Dale comments again, on this post, and is able to tell us whether the bone her worked on was Scap A or Scap B — and whether its present state is different from how he left it.)

Putting it all together, I think the weight of evidence says that Scap A is the holotype (BYU 9025, previously known as BYU 5500), with Jensen’s (1987:603) comment being our smoking gun. Other evidence includes Curtice and Stadtman’s (2001) observation that BYU 9025 is a left scap; its being about the right length (I trust my own scalebar, however informal, ahead of Lovelace et al.’s); and the fact that it is the better preserved of the two elements, making it a stronger candidate for having been selected as the holotype.

If that’s correct, then it is not without problems. It would follow that Lovelace et al. (2008:figure 10) is miscaptioned, being BYU 12962 and not 9025 as stated. It would also follow that Curtice and Stadtman were in error in describing the re-preparation of what was in fact the referred specimen BYU 12962 and not 9025 as stated.

Addendum: a cautionary tale

When I started this series of articles, I assumed that the NAMAL scap was the holotype (as you can see in the caption for the illustration of it in the first article). Why did I think that? Well, the Wikipedia article [archived link] says so: it has a photo of it captioned “The holotype of Supersaurus, scapulocoracoid BYU 9025″.

But as I got deeper into writing this series, I checked out the provenance of that photo on Wikipedia, only to find that it’s my own photo, as edited by Stephen O’Connor. Then I checked my emails to see whether I’d ever corresponded with Stephen, and I found that he’d emailed me three years ago including a link to this old SV-POW! photo of Scap A, and asking “I’m a little confused if the scapular in the image is a cast of holotype BYU 9025 or is it the opposing side, BYU 12962?” And I replied as follows:

Hi, Steve. I am attaching Jensen 1985, which is the canonical reference for this. Very poorly illustrated, though […]. Based on Figure 8 (page 708), the photo is a cast of “second specimen”. I’m attaching my photo of the holotype (“first specimen”) at NAMAL in Utah, in case it’s helpful.

So what happened here is that I over-interpreted a vague bit of hand-waving in Jensen 1985, fed it via Steve into Wikipedia, then trusted my own forgotten authority to reinforce the apparent legitimacy of my incorrect guess. I trusted Wikipedia on the identity of the NAMAL scap only to find it was my own assumption fed back to me.

A couple of days ago I read “Ninety percent of online journalism these days is nothing more than wannabe reporters summarizing other people’s assumptions from web sites that know how to game a search engine”.  I am pleased to find that I am efficient enough to cut out the wannae-reporter middle man from this process, and just summarise my own assumptions.

References

  • Curtice, Brian D. and Kenneth L. Stadtman. 2001. The demise of Dystylosaurus edwini and a revision of Supersaurus vivianae. Western Association of Vertebrate Paleontologists and Mesa Southwest Museum and Southwest Paleontologists Symposium, Bulletin 8:33-40.
  • Curtice, Brian D., Kenneth L. Stadtman and Linda J. Curtice. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). M. Morales (ed.), “The continental Jurassic”. Museum of Northern Arizona Bulletin 60:87–95.
  • George, Jean. 1973a. giant of the giants. Denver Post, Empire Magazine. May 13, 1973, pp 14ff.
  • George, Jean. 1973b. Supersaurus, the biggest brute ever. Reader’s Digest (June 1973):51–56.
  • George, Jean. 1973c. Supersaurus, the greatest of them all. Readers Digest (August 1973), page-range unknown.
  • Jensen, James A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45(4):697–709.
  • Jensen, James A. 1987. New brachiosaur material from the Late Jurassic of Utah and Colorado. Great Basin Naturalist 47(4):592–608.
  • Lovelace, David M., Scott A. Hartman and William R. Wahl. 2008. Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527–544.

 

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22 Responses to “Supersaurus, Ultrasaurus and Dystylosaurus in 2019, part 4: what is the holotype of Supersaurus?”

  1. william dale McInnes Says:

    Wow ! Fascinating story. It seems to change every time someone goes to re-prepare it. I really don’t think that is unique, a one-off. It probably happens everywhere. It also happened twice more at the R.A.M. when it was still the P.M.A.A. In the 1970’s, it was not the only mind boggling preparation I was involved with, that shared an even worse fate. In 1978, we excavated an absolutely gorgeous hadrosaur from a dried up riverbed aptly named Lost River (I really love that name). There has never been a hadrosaur specimen anywhere in the world like it. It was a COMPLETE mummy. The body impression did not collapse as did the earlier AMNH mummified hadrosaur. Currie and I went to N.Y. to compare it to ours. The original body contour was preserved. It fell over on top of a dense bush of deciduous leaves. It had also trapped a slurry of gastropods beneath it. As I removed these, the gastropods made large dimples in the skin. Understand that …. the hadrosaur’s original body contour was preserved intact. Its genitals were also preserved. It was the best preserved hadrosaur in the world at that time and probably still is/ was. So where’s the paper U ask ? Read on. The little guy was about 9′ in length (estimated at the time). Both Currie and I worked on this specimen intensely. There was a fortunate slit along the dorsal of this mummy. We saw what looked like a possible structure inside. We experimented. We had one crack at this. Currie had a brilliant idea. We mixed an acrylic red dye with the latex, then watered it down to the consistency of skim milk and poured it in. It took weeks of gradual pouring to allow the latex to build in thickness. The day came when we had to risk all. I gradually pulled the latex back out, exploding the original specimen (unfortunately), and we got an articulated skeleton (made of latex) to finally identify it. Like the Supersaurus scap, things change dramatically when the original people (like myself and others), leave an institution. Most of us left in 1982 – 4. I went back some 20 years later for a 3 – 4 week stint. A new assistant curator and some volunteer museum assistants were ordered to clear the field storage area of “debris”. This included that specimen. I panicked and stopped them as they were throwing it into an industrial waste bin. They thought someone in the early, early (made me feel like a fossil) dinosaur program from the last century were horsing around making rubber dino-skeletons for some weird reason. The blocks of sandstone (from the exploded specimen) could still be put back together. They hadn’t noticed the skin impressions on the other side of each of the blocks. It had already been prepared. Years later, I rechecked the field storage room on a one day visit. The specimen wasn’t there. It wasn’t cataloged in the collections. Another “new” crew had moved in. I think you know what most probably happened. That’s why no paper ever saw the light of publication on it …. no specimen to write about. Back in 1978 – 9, I did send a photo to George Olshevsky. Maybe he still has a photo of it ???

    The 3rd incident (1976-79), involved what could arguably be the most spectacular dinosaur trackway ever discovered … and yes … no paper ever published.

    Oh. BTW, the original photos of the big scap in our lab circa late 70s, might be in the possession of one Linda Strong-Watson. When the newly appointed (early 1980’s) Director of the R.T.M.P.,
    ordered most photos of our dinosaur program destroyed, a few enterprising individuals moved to secure them away, outside of the museum. How can people with no respect for the past be put in charge of a gov’t museum U ask ?? Well … uh … politics ??

  2. Mike Taylor Says:

    Dale, your stories are just so desperately sad.

    You really should have a blog of your own. These stories deserve to be told, and to be seen by a wide audience.

    Are you able to confirm that the element you prepped back in the 1970s is the one I’m referring to as “Scap B”?

  3. william dale McInnes Says:

    There were lots of photos taken of the scap that Jensen sent us. But that was 40 years ago. At that time, I was a little rebellious when the new Director was appointed. Strangely, I kind of liked him. But he had no grasp of history. It was all politics to him. He killed all the traditions we associated with in the field. He reminds me, very closely (in looks and temperament) of Donald Trump. If it was not associated with him, he wasn’t interested in it … period! I simply couldn’t remain under someone like that. So I resigned from the dinosaur program. To this day, I can still see Currie sitting at his desk, looking out the museum window, wistfully, while spinning the chamber of a museum revolver, putting it to his head, pulling the trigger, the sound of a “click” … and whispering to himself … “well maybe tomorrow”. (I’m being fictitious here but it did seem that way on many occasions). As I said before, that’s when our new, blond, wispy haired Director ordered all photographs of our early field program destroyed …. that didn’t include him. So, U will have to find those photos that were salvaged by our early team members. As I said, Ms. Strong-Watson is where I would direct my first inquiry. I no longer trust my memory. There was another famous individual that went through the same shit as we did … STROMER!!! He too had a new Director …. a Nazi …. dedicated to Hitler, who did not evacuate the dinosaur specimens from the Humboldt, collected from the Egyptian Bahariya oasis.

    I’m sure that Currie and I, both, once in a while, quietly cry ourselves to sleep thinking of the past. At least he has his wife to comfort him.

    Now, a box of tissue, before going into that Peace River dinosaur trackway ….


  4. Ahh! My name! Sooo…I’ve possibly, inadvertently, misled the WORLD for three years!?! Woops.

    The inconsistencies in Lovelace et al was one of the reasons why I was confused as to which was the holotype.

    Not only is Fig 10 stating the holotype is BYU 9025 ‘right’ scapulocoracoid and the Systemic Paleontology section stating that the holotype is BYU 12962 ‘Left’ scapulocoracoid, but also on the next page in Table 1 it states BYU 9025 ‘left’ scapulocoracoid as the holotype. Maybe Lovelace et al were just trying to cover all the bases? lol

    Either way, two out of three said ‘left’ and, with what research I had done, I was leaning towards the left scap, which was why I originally linked to the photo with Matt Wedel.

    So, in short, if Jensen 1987 is to be believed, ‘Scap A’ (Fig 9b), a left scapulocoracoid, is the holotype…and I was ‘right’ the first time? Probably. ;)

    I guess at some point when I get time I should upload a photo of Scap A and correct the Wiki article. Will it be ok to upload one of your photos above? Are they CC licensed?

  5. Mike Taylor Says:

    Steve, you are innocent. The blame is all mine. You approached me and offered (what we now believe to be) the correct identification of the holotype, and I “put you right” (i.e. set you wrong). You have my apologies.

    Yes, please do fix Wikipedia! Everything on SV-POW! is CC By unless otherwise noted: see the bottom of https://svpow.com/about/


  6. Cool thanks, no need to apologise. Your post makes it clear how unclear this all is.

    I’m sure simple errors/issues like these exist all over the literature. I’m currently looking into large whale shark reports and by attempting to illustrate them I have noticed several issues/mistakes with reported measurements, or with these measurements changing over time, false precision from converting ft to meters, etc.

  7. Mike Taylor Says:

    Yes, there certainly is a lot of this kind of thing about — especially when older papers are concerned, where “older” can mean as recent as the 1970s and 1980s. (Thankfully, recent literature tends to much more rigorous about specimen numbers, measurements and other picky details.)


  8. […] we even trust the assumption that the two scapulocoracoids were from the same animal? Maybe not. In favour of that possibility, the two elements are similar […]

  9. ijreid Says:

    Jensen’s drawing of the holotype Fig 8B matches the anatomy of presently BYU 12962 more, with the pointed posterodorsal acromion and broken blade expansion. But I’m not entirely sure what to think of that. It would match with Curtice’s statement BYU 12962 is the holotype, but clash with the holotype being a right scapulocoracoid.

  10. Mike Taylor Says:

    ijreid, I think you have now mixed up the specimens! Jensen (1985:figure 8B) is clearly Scap A, and his figure 8G is clearly Scap B. Based on the same illustration in Jensen (1987:figure 9), and on the text in page 602 of the same paper, figure 9B is the holotype BYU 5500 (= BYU 9025).

    Unless you have some reason I don’t know, for thinking that Scap A is BYU 12962?

  11. Emanuel Says:

    did you guys ask Rod Scheetz? As the collection manager at BYU (in the end, these are still BYU specimens, even though they’re on loan), he might have some additional information on this.

  12. Mike Taylor Says:

    My plan was to finish this series, then ask the BYU people (Brooks Britt as well as Rod Scheetz) to look over them all, rather than keep bothering them with each individual installment.


  13. […] part 5 of the Supersaurus series, I made the point that my photos of Scap A and Scap B seem to show them as being very different colours, suggesting different preservation. However […]

  14. Matt Wedel Says:

    Pretty sure that Scap A at Dinosaur Journey is a cast, and not the actual bone. I’ll write to Julia McHugh at DJ and confirm.


  15. […] is one of the two reasons why I am not persuaded that the very different colours of my photos of the two Supersaurus scapulae is strong evidence that they are from different […]

  16. Mike Taylor Says:

    Thanks, Matt. I did wonder whether it could really be that the Actual Scap is right out there where any passing doofus can hug it. But if that’s a cast, where is the real thing?

    (Also: if it’s a cast, that makes the whole different-colour-from-the-other-scap issue moot.)

  17. Matt Wedel Says:

    I heard back from Julia, and the scap on display at Dinosaur Journey is definitely a cast. The original might be at BYU, or — possibly — at a small museum in Delta, Colorado, that Vivian Jones used to curate, which displayed some specimens from Dry Mesa Quarry. Time for an inquiry to Brooks and Rod, methinks.


  18. […] age differently. Since then — newsflash! — a third reason has become apparent in the case of the two Supersaurus scaps: the object we discussed as Scap A turns out to be a cast. A really good one, sure, but still: its […]

  19. ijreid Says:

    The reason I thought Scap A was BYU 12962 is because Scap B is the one figured by Lovelace et al 2008 Fig 10, and labelled as BYU 9025. Jensen says the holotype is the right scapulocoracoid BYU 5500, which matches with BYU 9025 in both side and specimen number. And since the right scapulocoracoid is supposed to be the holotype BYU 9025, Scap A, which is the left scapulocoracoid, must be BYU 12962.

  20. Mike Taylor Says:

    @ijreid: Yes, it is true that Lovelace et al. (2008) figure Scap B and caption it as BYU 9025. You are also correct that Jensen (1985:701) — in the description, not in the diagnosis — says that the holotype BYU 5500 is a right scapulocoracoid. That’s a good catch.

    But note that Curtice and Stadtman (2001) say “a number of elements were referred to the holotype including the left scapulocoracoid discovered in 1972 (BYU 9025), a right scapulocoracoid (BYU 12962)”. The literature on these specimens is plagued with contradictions.

    Given that the contradictory left/right designations more or less cancel out, I think the best evidence we have remains Jensen’s (1987:602) comment that “(BYU 5500, Fig. 9B) is the holotype of Supersaurus vivianae“.

    But I agree that this is still not what you’d call a slam-dunk, and the whole situation is very unsatisfactory.

  21. Bruce Schumacher Says:

    Late to the party here. Must note however, Jensen (1985) does refers BYU 5500 (Scap A) as the holotype Scapula, but in description states:

    ” DESCRIPTION.—(Holotype BYU 5500; right scapulocoracoid) ”

    Scap A is a left, not a right.

    Perhaps some indication that Scap B (right) may be the holotype ?

    Bruce

  22. Mike Taylor Says:

    Could be. It’s absolutely infuriating that even now we don’t know which element is the holotype, and that the literature is actively contradictory. Clearly this is the first thing we need to lock down.


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