Bonus post: Supersaurus before Ultrasaurus!

July 11, 2019

I got a wonderful surprise a couple of nights ago!

Supersaurus referred scapulocoracoid BYU 12962 back when it was still in the ground. Rough composite assembled from screenshots of the video below, from about 23m17s.

I found myself wondering where the widely quoted (and ludicrous) mass estimate of 180 tons for Ultrasauros came from, and went googling for it. That took me to a blog-post by Brian Switek, which linked to a Google Books scan of what turned out to be my own chapter on the history of sauropod research (Taylor 2010) in the Geological Society’s volume Dinosaurs and Other Extinct Saurians: a Historical Perspective. So it turns out that I once knew the answer to that question. My chapter references McGowan (1991:118), which says:

Jim Jensen’s (1985) Ultrasaurus (“beyond lizard”), found in Colorado in 1979, had an estimated length of more than ninety-eight feet (30 m), compared with seventy-four feet (22.5 m) for the Berlin specimen of Brachiosaurus. This is a length increase of 1.32, so the weight increase would be (1.32)^3 = 2.3, giving an estimated weight of almost 180 tons.

[As I noted in my 2010 chapter, that’s based on Colbert’s (1962) equally silly estimate of 78 tonnes for MB.R.2181 (formerly HMN S II), the Girafatitan brancai paralectotype.]

So that’s a funny story and a mystery solved, but where it gets really good is that as I was grubbing around in the search results that led me to that conclusion, I stumbled on Episode 21 of the I Know Dino podcast, which contains a glorious embedded video: The Great Dinosaur Discovery, a 1976 film by BYU about Jensen’s work at quarries including Dry Mesa, and heavily featuring bones of what would become Supersaurus!

It’s very well worth 25 minutes of your time, despite the horrible 1970s documentary music, and brings actual new information to the table.

Some of the highlights include:

— Right from the start, seeing Jensen himself: someone I’ve been sort of familiar with from the literature, but never really imagined as being an actual human being.

— From about two minutes in, Jensen seems be uncovering bones in dry sand, rather like kids in a palaeo pits at some museums. It takes about one minute to uncover a nice tibia. Is it ever really that easy? Is the Dry Mesa quarry that easy to work?

— Putting faces to the important names of Vivian and Eddie Jones, the uranium prospectors who first led Jensen to several of his important sites, and after whom the species Supersaurus vivianae and Dystylosaurus edwini were named.

Vivian “Supersaurus” Jones and Eddie “Dystylosaurus” Jones in the field [from about 4m41s in the video]

— From about 13m30s onwards, we see what I think must be the Supersaurus pelvis that’s now on display at the North American Museum of Ancient Life. (It doesn’t actually look all that big, in the scheme of things.)

— From 16m50s onwards, things start to get real, with the uncovering (real or re-enacted) of the first Supersaurus scapulocoracoid: that is, the one that Jensen referred to in his 1985 paper as “first specimen”, but which in the end he did not designate as the holtotype. This bone, once accessioned, became BYU 12962 (but Jensen refers to it in his papers as BYU 5501).

The first appearance in the film of the Supersaurus scap BYU 12962 fully unconvered [18m11s]. You can easily recognise it as the bone that Jensen posed with from the lobe-shaped acromion process.

— Within seconds of our seeing the scap, Jensen decides the best thing to do is illustrate how it’s “like a sidewalk” by walking up and down on it. Seriously.

Oh, Jim.

— At about 19m30s, we see what is probably the big Barosaurus vertebra BYU 9024 whose identity Jensen changed his mind about a couple of times. Unfortunately, the film quality is very poor here, and you can’t make much out.

— From 20 minutes in, the video shows comparative skeletal reconstructions of Brontosaurus (clearly from Marsh 1891), “Brachiosaurus” [i.e. Giraffatitan] (clearly from Janensch 1950) and Supersaurus. The fascinating thing is that the latter is restored as a brachiosaurid — in fact, as a scaled-up Janensch-1950 Giraffatitan with some tweaks only to the head and anterior neck. So it seems Jensen thought at this time that he’d found a giant brachiosaur, not a diplodocid. (Note that this film was made three years before the Ultrasaurus scapulocoracoid was discovered in 1979, so the presumed brachiosaurid identity cannot have rested in that.)

Brontosaurus (yellow), Brachiosaurus (blue), and Supersaurus (white) — which is restored as a brachiosaurid.

— During this section, a fascinating section of narration says “The animal found here is so much larger than anything ever dreamed of, the press, for lack of scientific name, called it a Supersaurus.” If this is legit, then it seems Jensen is not guilty of coining this dumb name. It’s the first I’ve heard of it: I wonder if anyone can corroborate?

— As 22m06s we are told: “It was an AP newsman who broke the story to the world. Time and Life followed. Reader’s Digest ran the story. And National Geographic, one of the quarry sponsors, began an article.” I would love to get hold of the AP, Time, Life and National Geographic articles. Can anyone help? It seems that all these organisations have archives online, but they all suffer from problems:

Here’s that scap again, in the process of being excavated. [22:05]

— As 22m40s, Jack McIntosh turns up to give an expert opinion. I don’t know how much film of him there is out there, but it’s nice that we have something here.

Everyone’s favourite avocational sauropod specialist, Jack McIntosh.

— At 23:17, we get our best look at the scap, with a long, slow pan that shows the whole thing. (That’s the sequence that I made the composite from, that we started this whole post with.)

All in all, it’s a facinating insight into a time when the Dry Mesa quarry was new and exciting, when it was thought to contain only a single giant sauropod, when that animal was known only informally as “Supersaurus” having been so nicknamed by the media, and when it was (it seems) thought to be brachiosaurid. Take 25 minutes, treat yourself, and watch it.

Update (the next day)

The Wikipedia entry on Jim Jensen says that “In 1973, Brigham Young University cooperated with producer Steve Linton and director John Linton in order to produce The Great Dinosaur Discovery, a 1-hour-long color documentary showing Jensen’s on-site finds in Dry Mesa. […] the full-length documentary was reduced to a 24-minute-long mini-film which started airing on American television channels throughout the USA as of 1976.”

Can anyone confirm that the original date was 1973, and not 1976 as given on the short version that’s linked above?

And, more important, does anyone have access to the full-hour version?




24 Responses to “Bonus post: Supersaurus before Ultrasaurus!”

  1. william dale McInnes Says:

    You may not realize this but, Linda Strong-Watson and Phil Currie both worked side by side Jim Jensen in the Dry Mesa Quarry. I stayed with Jim for a while myself. His constant companion was Brooks B. Britt and a few other notables. Jim also stayed a while with us in Edmonton, Alberta, returning the favor. Everyone at the time (including Jack McIntosh) thought this was a possible brachiosaurid. Come to think of it, I have quite a few photos of our group in the Dry Meas quarry … late 70s I think. Damn !! I have just found a box in front of me labelled 1970-80s. Over 2-3000 photos. I’m almost positive I’ve got quarry shots and removal and opening shots of the scap sent back to us as well as the entire (at that time (9’2″) bone before prep and right after prep (memory’s coming back). Got too much on my plate dealing with tyrannosaurs to take the time to go through all this. Perhaps … later ?? No rush. right ??

  2. I wonder if there’s enough photos and footage of the scapula in the ground to do photogrammetry of it.

  3. Mike Taylor Says:

    @John: I did wonder that, but I don’t think you could get much.

    @Dale: (By the way, do you prefer William or Dale?) There’s evidently a ton of history out there waiting to be collected. It would be great to do that before memories fade, paperwork is thrown out and photos are lost. It’s funny now that everyone, McIntosh included, thought Supersaurus was brachiosaurid: we look at the scap now and think there’s nothing at all brachiosaurid about it. Not that it look obviously diplodocid either, mind. To be fair, I think scapulae are particularly hard to evaluate, not only because they seem to vary so much between individuals and through ontogeny, but also just because their curved shape is so difficult to photograph and measure in standardised ways.

    Could you perhaps find an enterprising student to digitise all those photos?

  4. william dale McInnes Says:

    I usually go by Dale (middle name)

  5. Thanks for the shoutout and link to I Know Dino! :)

  6. Mike Taylor Says:

    Hey, no problem Sabrina: thanks for finding that documentary!

  7. Ruben Guzman Says:

    I want to call your attention to the article “A new look at dinosaurs” by none but John H. Ostrom, published in the August 1978 issue of National Geographic magazine, where in pages 176-177 appears reconstructions of a a smaller and a bigger “Supersaurus” based on two shoulder blades and the picture of Jim Jensen besides one of them still in situ. I tried to post a link to the pdf of the magazine earlier but apparently the website identified it as spam, let me know and I’ll be glad to send a pdf copy of it.

  8. Mike Taylor Says:

    That’s great! Many thanks for finding that. You can email it to me at

  9. Rob Says:

    @Laelaps now goes by Riley Black (they/them; see -, just fyi. Obviously citing things on the internet gets a little freeform, but since you’re linking directly to their blog post, and they aren’t explicitly named therein, seems like using their current name doesn’t lose any information. =)

  10. Mike Taylor Says:

    Thanks, Rob. Without getting into the complexities surrounding this, I think the scientific record is best served if we cite works as being by the author whose name is given in that work. (In this case the writing is given only as by Laelaps, but the name Brian Switek is credited with the interpolated photo of the Supersaurus mount.) It’s the same principle that means Schwartz and Fritsch (2006) on pneumaticity in the necks of Tendaguru sauropods remained Schwartz and Fritsch (2006) after Daniela had taken the name Schwarz-Wings.

  11. Rob Says:

    I understand that’s the standard format for citation (although one might posit that “hey, women also have to compromise to participate in this system build by men, for men” is perhaps not the most winning defense), and if you had referred to the article as “(Switek, 2014)” or similar I wouldn’t have said anything. It seems unnecessary to use their entire former name in the context of a more informal citation, particularly as their former first name also suggests pronouns they no longer use. Thanks for considering.

  12. Mike Taylor Says:

    Like I said, Rob, I’m not going to get into this.

  13. […] — A shortened version of The Great Dinosaur Discovery is made available for schools. (At present, this is the only version we have access to.) In this version of the film (and presumably in the 1973 original, if the 1976 version was made […]

  14. […] so the series continues: part 9, part 10 and part 11 were not numbered as such, but that’s what they were, so I am picking up […]

  15. Mike Taylor Says:

    Note to self: there is a better-quality copy of the same video at

  16. Liviu Urziceanu Says:

    It s somehow out of topic. In 2017 in Australia there were found footprints of 1.7 m deemed to be the largest in the world. Steve Salisbury, a vertebrate palaeontologist at the University of Queensland told ABC News: “We’ve got several tracks up in that area that are about 1.7 metres long. So most people would be able to fit inside tracks that big, and they indicate animals that are probably around 5.3 to 5.5 metres at the hip”. My question is – such big footprints couldn’t be from a record breaking sauropod?
    Kind regards
    Liviu Urziceanu

  17. Mike Taylor Says:

    Hi, Liviu. Tracks are difficult to interpret, as they are affected not only by the animal, but also by the sediment. It’s clear that there were some very big sauropods down in Salisbury’s site, but we’re a bit limited on what we can say about exactly how big. See Matt’s ten-year-old post for some numbers, but take them with a pinch of salt.

  18. william dale McInnes Says:

    Oh Good grief !!! Thousands of photos from the 1970’s to go through and now a filing cabinet of tons of correspondence with both Jim Jensen and Jack McIntosh from the 1970’s dealing with the newly uncovered Dry Mesa specimens. If I were to die tomorrow, my family (not into palaeontology) would most probably throw all this out. So. I’ve got to archive all this somehow. This stuff is more than a 1/2 century old. All correspondence was done by hand written letters and drawings. Even letters by Efrimov, Maleev and (Chien Chung Young and Michen Chow (founding fathers of China’s palaeontology and participants in the Roy Chapman Andrews expeditions). These letters date way back to the late 1950s – early 60s. Funny what U set aside after 60 – 70 years. Its an old filing cabinet at the back and in the far corner of one of my closets. I eagerly dove into the back of the closet, buried in so much “junk”, only to discover that the drawers were individually locked. No keys. Ten years ago, I had these precious keys and couldn’t remember what they were for. Kept them for years in case I remembered. Nope. So tossed them. Now I remember. Isn’t that the way it always is !?! One day, I’ll have to set aside an entire week to break into this cabinet and go through this archival stuff. U never think its worth anything special until long after its fossilized. Being a pack rat for palaeontology sometimes pays off.

  19. Mike Taylor Says:

    Wow, Dale, that is amazing that you have all these treasures!

    Yes, yes, please archive and digitise! (Or failing that, UPS the filing cabinet to me :-) )

  20. william dale McInnes Says:

    Maybe we’ll get some answers now. I distinctly remember showing Phil Currie some of this. I was surprised that he seemed astounded. I thought every kid in the 1950s in dinosaurology wrote to all the great ones. After all, U could count all of them on just 2 hands. I remember Glen Jepsen and Stovall and the conversations I had with them. But Colbert, Russell, Coombs, Ostrom and Mcintosh were the ones I brushed shoulders with and personally met. I remember when a soviet visitor, none other than Maleev himself dropped in quite unexpectedly in 1970’s Edmonton, Canada. He was also quite proud to have been chosen one of the Soviet Union’s most highly regarded sci-fi writers of his day. I enjoyed a particularly long conversation with Charles Sternberg and our rather personal discussions of Gilmore, Barnum Brown and Walter Grainger. I only wish I had had the sense to record our conversations and taken pics. But I did get some personally autographed papers from some of these guys. In those days … they were gods to me.

  21. Liviu Urziceanu Says:

    In 2017 there was some hype about a so called “french monster dinosaur” with a alleged 2.6 m long femur, another 2.2 m femur, a giant rib and a giant fibula. Any news about this dinosaur or any estimate? Some claimed it was one of the largest dinosaur. Any basis for these allegations?
    thank you very much
    Kind regards

  22. Mike Taylor Says:

    Hi, Liviu. I only vaguely remember the story you’re referring to here — I’ve seen a lot of them over the years. I think on the whole we now wait for formal publication before getting too excited. I certainly hope it’s true, though! The Berlin brachiosaur, with its femur restored to 196 cm per Janensch (1950b) probably massed about 30 tonnes. A 2.6 m femur is 33% longer than Janensch’s specimen, suggesting a mass 1.33^3 times as great: 2.33 * 30 tonnes would come to about 70 tonnes. Not to be sniffed at.

  23. Asier Larramendi Says:

    There is no 2.6 femur, just a distal end which is considerably larger than the complete 2.2 m. The giant fragment suggests that the total length of the femur would be in 2.5 – 2.6 m region. French monster might be an early somphospondylian with a considerably lighter body built than Giraffatitan (just take look to the extremely slender femur), so it could have been “only” about 50 tonnes or less.

  24. Mike Taylor Says:

    OK, thanks, Asier. Shame, but this is so often the way: there is less of giant specimens than we would hope.

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