I am co-authoring a manuscript that, among other things, tries to trace the history of the molds made by the Carnegie Museum in the early 1900s, from which they cast numerous replica skeletons of the Diplodocus carnegii mount (CM 84, CM 94, CM 307 and other contributing specimens). This turns out to be quite a mystery, and I have become fascinated by it.

Below is the relevant section of the manuscript as it now stands. Can anyone out there shed any further light on the mystery?

So far as we have been able to determine, the casting of the concrete Diplodocus of Vernal was probably the last time the Carnegie Museum’s original molds were used. However, that was not Untermann’s intention. In his 1959 account, he wrote (p368–369):

Several museums in the United States and from lands as distant as Japan and Italy have expressed a desire to acquire the molds and cast a Diplodocus of their own from either plaster or some of the newer synthetics. To date no museum has apparently been able to make satisfactory arrangement for the acquisition of the molds and the casting of a skeleton. We still have the molds in Vernal, and any museum, anywhere, is welcome to them just for hauling them off. […] The Diplodocus on the lawn of the Utah Field House is the eleventh replica to be cast from the molds […] Does anyone wish to cast the twelfth?

From here, though, the story becomes contradictory. Sassaman (1988) reported that “the molds finally fell apart because of old age soon after it [the concrete Diplodocus] was made”. Similarly, Ilja Niewland (pers. comm., 2022) said that “The original moulds were thrown away somewhere during the 1960s (nobody at the [Carnegie Museum] could be more specific than that)”, suggesting that the molds may have been returned to their origin.

Both these accounts seem to be in error, as shown by a 1960 report in the Vernal Express newspaper (Anonymous 1960a; Figure H; see also Carr and Hansen 2005). This says that in the middle of July 1960, the molds were collected by the Rocky Mount Children’s Museum (now the Rocky Mount Imperial Center, Children’s Museum & Science Centre) in North Carolina, with the intention that they would be used to create a twelfth cast which would be mounted outside the museum building next to the Tar River in Rocky Mount’s Sunset Park. But was such a cast ever created? A sequence of reports in the Rocky Mount Evening Telegram from April to July 1960 (Williams 1960, Bell 1960a, Bell 1960b, Anonymous 1960b) enthusiastically announce and discuss the impeding arrival, and the later articles say that museum board president Harold Minges has left for Utah to collect to molds — but then the newspaper goes silent on the subject, and the project is never mentioned again. There is no positive evidence that the molds even arrived in Rocky Mount, far less that they were used to create a new mount. Thus newspaper reports from both Utah and North Carolina say that the molds set out on their journey from one to the other, but neither confirms that they ever arrived. On the other hand, there is also no report of the molds being lost or destroyed, so perhaps the most likely interpretation is that they arrived in Rocky Mount, but were found to be in worse condition than expected and quietly left in storage. This interpretation is supported by Rea (2001:210) who reported that “from Vernal the molds kept travelling — first, to the Rocky Mount Children’s Museum in Rocky Mount, North Carolina, although a cast was never made there”. Similarly, Moore (2014:234-235) stated that “From Vernal, Utah, [CM] molds of Diplodocus carnegii are shipped to Rocky Mount Children’s Museum in Rocky Mount, North Carolina. Because of the age-related damage to the molds, a cast was never prepared”.

Hurricane Floyd devastated Rocky Mount in 1999, with flooding from the River Tar destroying the original Children’s Museum along with all its exhibits and records (Leigh White, pers. comm., 2022), so no records survive that could confirm the molds’ arrival or any subsequent use. The museum was located next door to a municipal water treatment facility that also flooded and released unknown chemicals, so museum property that might have otherwise been salvageable in that area was deemed contaminated and required to be destroyed. If the molds were in storage at the Children’s Museum at this time, then this was likely the end of their story.

The Children’s Museum was re-established at the newly built Imperial Centre, where it still resides, but no trace exists there of molds or casts of Diplodocus. Corroborating the hypothesis that no cast ever existed, most staff who worked at the museum in the 1980s do not recall any such cast (Leigh White, pers. comm., 2022). Contradicting this, however, Jan Engle Hicks, Curator of Education at the Rocky Mount Children’s Museum from 1971–2002, has a memory of Diplodocus casts being on exhibit at the museum when she started work in 1971. She does not recall if they were still part of the museum collection in 1999 when the collection was destroyed.

Whether or not a cast was made at Rocky Mount, it is possible that this was not the end for the molds. Rea (2001:210) continues: “Eventually the molds found their way to the Houston Museum of Science, where they were used to fill in gaps in the Diplodocus hayi skeleton that had been swapped from Pittsburgh to Cleveland before ending up in Houston”, citing a personal communication from John S. McIntosh. (The skeleton in question is that of CM 662, which became CMNH 10670 in Cleveland, then HMNS 175 in Houston. Having been nominated as the holotype of the new species Diplodocus hayi by Holland (1924:399), the species was later moved to its own new genus Galeamopus by Tschopp et al. (2015:267).)

Due to the loss of the Rocky Mount Children’s Museum records, we cannot tell whether they ever shipped the molds to Houston; and we have not been able to obtain information from the Houston Museum. Brian Curtice (pers. comm., 2022) reports that he was in Houston in 1995 and did not see the molds in the collection, nor hear of their ever having been there. In the absence of evidence that the molds ever made it to Houston, it seems at least equally likely that the missing bones in HMNS 175 were cast and supplied by Dinolab, using the second-generation molds described blow, and that Rea (2001) misreported this.

As recently as 1988, Rolfe (1988) wrote on behalf of the Royal Museum of Scotland, “At present I am exploring the possibility of re-using the Carnegie Museum, Pittsburgh moulds, although there is considerable doubt about whether they are up to the job, after so much previous use”. Sadly, his letter does not mention their then-current whereabouts.

In an unpublished manuscript, Madsen (1990:4) wrote that “The fate of the initial set of molds is somewhat in question, but Wann Langston (personal communication, 1989) suggests that they seem to have been lost, strayed, or stolen during transport from ? to ?. Principles contacted in regards to the disposition of the molds could not provide specific information.”. Infuriatingly, the question marks are in the original. Since both Langston and Madsen are now deceased, there is no way to discover on which of the molds’ journeys Langston thought they were lost or destroyed. It is unlikely, at least, that Langston had in mind the their initial journey from Vernal to Rocky Mount. Kirby (1998:4) wrote that “Somewhere along the line, as the story goes, the molds received from the Carnegie had been shipped to a school down south and never arrived. So they were lost”. Since Rocky mount is about 2000 miles east (not south) of Vernal, “a school down south” could not have referred, in a Utah publication, to a museum out east. The Houston museum also does not seems an especially likely candidate for this designation, being 1300 miles southeast of Vernal.

Putting it all together, there is no way that all the reports cited here can be accurate. Perhaps the most likely scenario is this: the molds were successfully shipped to Rocky Mount in July 1960 (Anonymous 1960a, Anonymous 1960b) but found to be unusable (Rea 2001:210, Moore 2014:234-235) and left in storage. At some later point there were shipped to a school in a southern state (Kirby 1998:4) but did not arrive (Langston cited in Madsen 1990:4). This may have happened in late 1988 or early 1989, between Rolfe’s (1988) letter that expressed an interest in using the molds and Langston’s personal communication to Madsen in 1989. Where the molds are now, and why they did not arrive, we can only speculate. As Madsen (1990:4) concluded, “It is truly a mystery that an estimated 3–6 tons of plaster molds could simply vanish!”


Anonymous. 1960a. Dinosaur molds take long ride to No. Carolina children’s home. Vernal Express, 14 July 1960, page 15. https://newspapers.lib.utah.edu/ark:/87278/s6zk6w6s/21338221

Anonymous. 1960b. Something ‘big’ for a fact. Rocky Mount Evening Telegram, 8 July 1960, page 4A. https://newspaperarchive.com/rocky-mount-evening-telegram-jul-08-1960-p-4/

Bell, Mae. 1960a. Dinosaur’s coming here brings questions galore. Rocky Mount Evening Telegram, 14 May 1960, page 2. https://newspaperarchive.com/rocky-mount-evening-telegram-may-14-1960-p-2/

Bell, Mae. 1960b. ‘Dinosaur’ soon to arrive here. Rocky Mount Evening Telegram, 3 July 1960, page 3A. https://newspaperarchive.com/rocky-mount-evening-telegram-jul-08-1960-p-8/

Carr, Elaine, and Aric Hansen. 2005. William Randolf Turnage, Dee Hall, and Ernest Untermann [archive photograph with metadata]. University of Utah, J. Willard Marriott Digital Library, image 1086142. https://collections.lib.utah.edu/details?id=1086142

Holland, William J. 1924. The skull of Diplodocus. Memoirs of the Carnegie Museum 9(3):379–403.

Kirby, Robert. 1998. Danny and the dinosaurs. Chamber Spirit (newsletter of the Vernal area Chamber of Commerce) 3(4):1–6.

Madsen, James H. 1990. Diplodocus carnegiei: Production and design of replica skeletons. Unpublished draft manuscript. (No author is named in the manuscript, but Madsen’s son Chris believes it is his work.)

Moore, Randy. 2014. Dinosaurs by the Decades: A Chronology of the Dinosaur in Science and Popular Culture. Greenwood, Westport, Connecticut.

Rea, Tom. 2001. Bone Wars: The Excavation and Celebrity of Andrew Carnegie’s Dinosaur. University of Pittsburgh Press, Pittsburgh, PA.

Rolfe, William D. I. 1988. Untitled letter to LuRae Caldwell (Utah Field House). 24 October 1988.

Sassaman, Richard. 1988. Carnegie had a dinosaur too. American Heritage 39(2):72–73.

Tschopp, Emanuel, Octávio Mateus and Roger B. J. Benson. 2015. A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda). PeerJ 2:e857. doi:10.7717/peerj.857

Untermann, G. Ernest. 1959. A replica of Diplodocus. Curator 2(4):364–369. doi:10.1111/j.2151-6952.1959.tb00520.x

Williams, Oliver. Pre-historic dinosaur to tower over city; giant animal four times taller than man. Rocky Mount Evening Telegram, 24 April 1960, page 3B. https://newspaperarchive.com/rocky-mount-evening-telegram-apr-24-1960-p-11/

I’ve been in contact recently with Matt Lamanna, Associate Curator in the Section of Vertebrate Paleontology at the Carnegie Museum of Natural History — which is obviously the best job in the world. Among a batch of photos that he sent me recently, I seized on this gem:

Tyrannosaurus rex, Diplodocus carnegii, Apatosaurus louisae and multiple mostly juvenile individuals of Homo sapiens. Photograph taken between 1941 and 1965. Courtesy of Carnegie Museum of Natural History.

There’s so much to appreciate in this picture: the hunchbacked, tail-dragging Tyrannosaurus; the camarasaur-style skull on the Apatosaurus; the hard-to-pin-down archaic air of Diplodocus.

But the thing I love about it is the 1950s kids. (Or, to be fair, maybe the 1940s kids or early 1960s kids, but you get the point.) They way they’ve all been asked to look up at the tyrannosaur skull, and are obediently doing it. How earnest they all appear. How they’re all dressed as tiny adults. How self-consciously some of them have posed themselves — the thoughtful kid one in from the left, his foot up on the plinth and his chin resting on his hand; the cool kid to his right, arms crossed, interested but careful not to seem too impressed.

Where are these kids now? Assuming it was taken in 1953, the midpoint of the possible range, and assuming they’re about 12 years old in this photo, they were born around 1941, which would make them 81 now. Statistically, somewhere around half of them are still alive. I wonder how many of them remember this day, and the strange blend of awe, fascination, and self-consciousness.

This is a time-capsule, friends. Enjoy it.

We’ve shown you the Apatosaurus louisae holotype mounted skeleton CM 3018 several times: shot from the hip, posing with another massive vertebrate, photographed from above, and more. Today we bring you a world first: Apatosaurus from below. Scroll and enjoy!

Obviously there’s a lot of perspective distortion here. You have to imagine yourself lying underneath the skeleton and looking up — as I was, when I took the short video that was converted into this image.

Many thanks to special-effects wizard Jarrod Davis for stitching the video into the glorious image you see here.

The most obvious effect of the perspective distortion is that the neck and tail both look tiny: we are effectively looking along them, the neck in posteroventral view and the tail in anteroventral. The ribs are also flared in this perspective, making Apato look even broader than it is in real life. Which is pretty broad. One odd effect of this is that this makes the scapulae look as though they are sitting on top of the ribcage rather than appressed to its sides.


Here at SV-POW! Towers, we like to show you iconic mounted skeletons from unusual perspectives. Here’s one:

Apatosaurus louisae holotype CM 3018, mounted skeleton in the public gallery of the Carnegie Museum of Natural History: head, neck, torso and hip in right posterolateral view. Photograph by Matt Wedel, 12th March 2019 (my birthday!)

Oh, man, I love that museum. And I love that specimen. And I love the one that’s standing next to it (Diplodocus CM 82, natch.) I’ve got to find a way to get myself back out there.

That’s all: just enjoy.

For this forthcoming Barosaurus paper, we would like to include an establishing photo of the AMNH Barosaurus mount. There are two strong candidate photos which we’ve used before in an SVPCA talk, but since this is a formal publication we need to be more careful about copyright. Here are the photos, which are the property of their respective rightsholders:

This one is hard to find at all, at least using Google’s reverse image search. Whereas this one …

… is sprinkled all over the Internet, but (in all the cases I’ve seen so far) without attribution.

Does anyone have the necessary skills to track down who the rightsholder is for either of these? Thank you!

FMNH P13018 with me for scale. Photo by Holly Woodward.

Some of the Burpee Museum folks and PaleoFest speakers visited the Field Museum of Natural History in Chicago after the 2020 ‘Fest. I hadn’t been there since 2012, and a lot had changed. More on that in future posts, maybe. Here I am with FMNH 13018, a right femur referred by von Huene (1929) to Argyrosaurus superbus (note, though, that Mannion and Otero 2012 considered this specimen to be Titanosauria indet., hence the hedge in the title of the post). It’s 211cm long, which is pretty darn big but still well short of the record.

Speaking of the record, here’s a list of the largest sauropod femora (as always, updates in the comments are welcome!):

  1. 250cm – Argentinosaurus huinculensis, MLP-DP 46-VIII-21-3 (estimated when complete)
  2. 238cm – Patagotitan mayorum, MPEF-3399/44
  3. 236cm – Patagotitan mayorum, MPEF-PV 3400/27
  4. 235cm – Patagotitan mayorum, MPEF-PV 3400/27
  5. 235cm – “Antarctosaurus” giganteus, MLP 26-316
  6. 214cm – Giraffatitan brancai, XV1
  7. 211cm – cf. Argyrosaurus superbus, FMNH P13018
  8. 203cm – Brachiosaurus altithorax, FMNH P25107
  9. 200cm – Ruyangosaurus giganteus, 41HIII -0002 (estimated when complete)
  10. 191cm – Dreadnoughtus schrani, MPM-PV 1156

The list is necessarily incomplete, because we have no preserved femora for Puertasaurus, Notocolossus, Futalognkosaurus, or the largest individuals of Sauroposeidon and Alamosaurus, all of which probably had femora in the 210-250cm range. For that matter, most elements of the giant Oklahoma apatosaurine are 25%-33% larger than the equivalent bones in CM 3018, which implies a femur length of 223-237cm (scaled up from the 178.5cm femur of CM 3018). I’m deliberately not dealing with Maraapunisaurus or horrifying hypothetical barosaurs here.

In any case, it’s still a prodigious bone, and well worth spending a moment with the next time you’re at the Field Musuem.


  • Mannion, P.D. and Otero, A., 2012. A reappraisal of the Late Cretaceous Argentinean sauropod dinosaur Argyrosaurus superbus, with a description of a new titanosaur genus. Journal of Vertebrate Paleontology, 32(3):614-638.
  • Von Huene, F. 1929. Los saurisquios y ornitisquios del Creta´ceo Argentino. Anales del Museo de La Plata 3:1–196.

My Oct. 13 National Fossil Day public lecture, “Lost Giants of the Jurassic”, for the Museums of Western Colorado – Dinosaur Journey is now up on their YouTube channel. First 48 minutes are talk, last 36 minutes are Q&A with audience, moderated by Dr. Julia McHugh. New stuff from the 2021 field season — about which I’ll have more to say in the future — starts at about the 37-minute mark. Hit the 44-minute mark (and this and this) to find out what to do with all of the unwanted bird necks that will be floating around at the upcoming holidays.

Finally, big thanks to Brian Engh for finding our brachiosaur and for letting me use so much of his art, to John Foster, Kaelen Kay, Tom Howells, Jessie Atterholt, Thierra Nalley, and Colton Snyder for such a fun field season this year, and to Julia McHugh for giving me the opportunity to yap about one of my favorite dinosaurs!


The last time we saw the sauropod femur that Paige Wiren discovered sticking out of a riverbank, it had been moved into the prep lab at the Moab Museum, with the idea that it would eventually go on exhibit as a touch specimen for the public to enjoy and be inspired by. That has come to pass.

I was in Moab last month with Drs. Jessie Atterholt and Thierra Nalley and we stopped in the Moab Museum to digitize some vertebrae from SUSA 515, an unusual specimen of Camarasaurus that I’ve blogged about before, and will definitely blog about again. While we were there, we got to see and touch the Wiren femur. The museum folks told us that femur has been the first dinosaur bone that a lot of schoolkids and tourists have seen up close, or gotten to touch. As a former dinosaur-obsessed kid who never stopped being excited about touching real dinosaur bones–and as one of the lucky folks that got to rescue this particular fossil from erosion or poaching–that pleases me deeply. 

So, obviously, you should go see this thing. And the rest of the museum–as you can see from the photos above, the whole place has been renovated, and there are lots of interesting fossils from central and eastern Utah on display, not to mention loads of historical artifacts, all nicely presented in a clean, open, well-lit space that invites exploration. Go have fun!

I have the honor of giving the National Fossil Day Virtual Lecture for The Museums of Western Colorado – Dinosaur Journey, next Wednesday, October 13, from 7:00 to 8:00 PM, Mountain Daylight Time. The title of my talk is “Lost Giants of the Jurassic” but it’s mostly going to be about Brachiosaurus. And since I have a whole hour to fill, I’m gonna kitchen-sink this sucker and put in all the good stuff, even more than last time. The talk is virtual (via Zoom) and free, and you can register at this link.

The photo up top is from this July. That’s John Foster (standing) and me (crouching) with the complete right humerus of Brachiosaurus that we got out of the ground in 2019; that story is here. The humerus is in the prep lab at the Utah Field House of Natural History State Park Museum in Vernal, and if you go there, you can peer through the tall glass windows between the museum’s central atrium and the prep lab and see it for yourself.

If you’ve forgotten what a humerus like that looks like in context, here’s the mounted Brachiosaurus skeleton at the North American Museum of Ancient Life with my research student, Kaelen Kay, for scale. Kaelen is 5’8″ (173cm) and as you can see, she can just get her hand on the animal’s elbow. The humerus–in this case, a cast of the right humerus from the Brachiosaurus altithorax holotype–is the next bone up the line. Kaelen came out with us this summer and helped dig up some more of our brachiosaur–more on that story in the near future.

Want more Brachiosaurus? Tune in next week. Here’s that registration link again. I hope to see you there!

Last spring I was an invited speaker at PaleoFest at the Burpee Museum of Natural History in Rockford, Illinois. I meant to get these photos posted right after I got back. But I flew back from Illinois on Monday, March 9, 2020, and by the following weekend I was throwing together virtual anatomy labs for the med students. You know the rest. 

The wall of ceratopsians at the Burpee Museum. Every museum should have one of these.

I had a fantastic time at PaleoFest. The hosts were awesome, the talks were great, the Burpee is a cool museum to explore, and the swag was phenomenal.

An ontogenetic series of Triceratops skulls. Check out how the bony horn cores switch from back-curving to forward-curving. The keratin sheaths over the horn cores elongated, but they didn’t remodel, so adult trikes probably had S-curving horns.

I know I poke a lot of fun at non-sauropods around here, but the truth is that I’m a pan-dino-geek at heart. When I’m looking at theropods and ceratopsians I am mostly uncontaminated by specialist knowledge or a desire to work on them, so I can relax, and squee the good squee.

I’m a sucker for dinosaur skin. It’s just mind-blowing that we can tell more or less what it would feel like to pet a dinosaur.

Among the memorable talks last year: Win McLaughlin educated me about rhinos, which are a heck of a lot weirder than I thought; Larisa DeSantis gave a mind-expanding talk about mammalian diets, evolution, and environmental change; and Holly Woodward explained in convincing detail why “Nanotyrannus” is a juvenile T. rex.

The pride of the Burpee Museum: Jane, the juvenile T. rex.

But my favorite presentation of the conference was Susie Maidment’s talk on stegosaurs. It was one of the those great talks in which the questions I had after seeing one slide were answered on the next slide, and where by end of the presentation I had absorbed a ton of new information almost effortlessly, by  just listening to an enthusiastic person talk almost conversationally about their topic. And when I say “effortlessly”, I mean for the audience–I know from long experience that presentations like that are born from deep, thorough knowledge of one’s topic, deliberate planning, and rehearsal.

The big T. rex mount is pretty great, too.

That’s not to slight the other speakers, of course. All the talks were good, and that’s not an easy thing to pull off. Full credit to Josh Matthews and the organizing committee for putting on such an engaging and inspiring conference.

Did I say the swag was phenomenal? The swag was phenomenal. Above are just a few of my favorite things: a Burpee-plated Rite-in-the-Rain field notebook, a fridge magnet, a cool sticker, and at the center, My Precious: a personalized Estwing rock hammer. Estwing makes nice stuff, and a lot of paleontologists and field geologists carry Estwing rock hammers. Estwing is also based in Rockford, and they’ve partnered with the Burpee Museum to make these personalized rock hammers for PaleoFest, which is pretty darned awesome.

I already had an Estwing hammer–one of blue-grip models–which is good, because the engraved one is going in my office, not to the field. (If you’re wondering why my field hammer looks so suspiciously unworn, it’s because my original was stolen a few years ago, and I’m still breaking this one in. By doing stuff like this.)

There’s a little Burpee logo with a silhouette of Jane down at the end of the handle, so I had to take Jane to meet Jane.

Parting shot: I grew up in a house out in the country, about 2 miles outside of the tiny town of Hillsdale, Oklahoma, which is about 20 miles north of Enid, which is about 100 miles north-northwest of Oklahoma City. Hillsdale is less than an hour from Salt Plains National Wildlife Refuge, where you can go dig for selenite crystals like the ones shown above. The digging is only allowed in designated areas, to avoid unexploded ordnance from when the salt plains were used as a bombing range in World War II, and at certain times of year, to avoid bothering the endangered whooping cranes that nest there.

I don’t know how many times I went to Salt Plains to dig crystals as a kid, either on family outings or school field trips, but it was a lot. I still have a tub of them out in the garage (little ones, nothing like museum-quality). And there are nice samples, like the one shown above, in the mineral hall of just about every big natural history museum on the planet. One of my favorite things to do when I visit a new museum is go cruise the mineral display and find the selenite crystals from Salt Plains. I’ve seen Salt Plains selenite in London, Berlin, and Vienna, and in most of the US natural history museums that I’ve visited for research or for fun. The farm boy in me still gets a little thrill at seeing a little piece of northwest Oklahoma, from a place that I’ve been and dug, on display in far-flung cities.

I already credited Josh Matthews for organizing a fabulous conference, but I need to thank him for being such a gracious host. He helped me arrange transportation, saw that all my needs were met, kept me plied with food and drink, and drove me to Chicago, along with a bunch of other folks, for a Field Museum visit before my flight home, which is how I got this awesome photo, and also these awesome photos. Thanks also to my fellow speakers, for many fascinating conversations, and to the PaleoFest audience, for bringing their A game and asking good questions. I didn’t know that PaleoFest 2020 would be my last conference for a while, but it was certainly a good one to go out on.