How the Concrete Diplodocus paper came to be

February 23, 2023

Last time, I told you about my new paper, The Concrete Diplodocus of Vernal (Taylor et al. 2023), and finished up by saying this: “But Mike, you ask — how did you, a scientist, find yourself writing a history paper? It’s a good question, and one with a complicated answer. Tune in next time to find out!”

Paper 1

The truth is, I never set out to write a history paper. My goal was  very different: to belatedly write up my and Matt’s 2016 SVPCA presentation, How Big Did Barosaurus Get? (Taylor and Wedel 2016). In that talk, we discussed a half-prepared jacket at BYU that contains three Barosaurus cervicals which are significantly larger than those of the well-known specimen AMNH 6341. And we went on to note that the giant “Supersaurus” cervical BYU 9024 is morphologically indistinguishable from those of Barosaurus, even though it’s going on for twice the size.

That paper (codename: superbaro) is in progress, and I would estimate it’s about 40% done. But in that paper, I needed to write a brief section in the introduction about AMNH 6341, the keystone specimen for Barosaurus, from which all our perceptions of that animal derive. And it turned out that in that section I had a lot to say, to the point where …

Paper 2

It became apparent that this section needed to be pulled out and become its own paper on the AMNH Barosaurus. As I worked on this, trying to get to the bottom of the complicated history of the mounted cast in the museum’s atrium, I got a lot of help from Peter May of Research Casting International, and from AMNH alumni Lowell Dingus and Gene Gaffney, to the point where they have all been added as authors to the ongoing manuscript.

That paper (codename: baromount) is in progress, and I would estimate it’s about 80-90% done. But in that paper, I needed to write a section on the sources of the various elements that make up the cast — they are not all from AMNH 6341, which is pretty complete as sauropods go but still has a lot of gaps. It turned out, after some poking about, that significant parts of the skeleton were Diplodocus casts, and that they had been made from molds taken from a concrete cast in Vernal, Utah. I started to write up the background information on this, but quickly realised that there was a lot to say, and that it needed to be extracted out into its own paper.

Paper 3

Taylor et al (2023:figure 4). Assembly of the outdoor concrete Diplodocus at the Utah Field House in 1957. (A) In right posterolateral view. The sacrum and fused ilia having been mounted on the main support to begin the process, the hind limbs, last four dorsal vertebrae and first caudal vertebra have now been added. (B) In left anterodorsolateral view, probably taken from the roof of the museum. The mount is almost complete, with only the forelimbs, their girdles and the dorsal ribs yet to be attached. Note that, contra Untermann (1959, p. 367–368), the skull is already in place. Both images scanned by Aric Hansen for the J. Willard Marriott Digital Library, image IDs 1090660 and 1090647. Used by permission, Uintah County Library Regional History Center.

That paper, of course, became The Concrete Diplodocus of Vernal. As I was working on it, I found myself constantly consulting park manager Steve Sroka, and quickly realised that the manuscript had reached the stage of being co-authored. Later in the process, significant contributions from Ken Carpenter went beyond the point of pers. comms, and he was added as a third author. (This paper also received a lot of help from other people, and the acknowledgements are correspondingly extensive and effusive.)

So that is the origin story of yesterday’s paper. But there is another chapter in this story …

Paper 4

As I was writing the section of this paper about the original Carnegie Diplodocus, and in particular about the composition of the mounted skeleton from which the original molds were (mostly) made, it became apparent that this, too, was a long and complicated story. And even though that story has been told in detail multiple times (most notably by Nieuwland 2019), there was still plenty to be told. So this section needed to be pulled out of the CDoV paper (where only a brief summary remains) and become its own paper.

That paper (codename: carnegie) is in progress, and I would estimate it’s about 90-95% done. It, too, has acquired co-authors, including Ilja Nieuwland himself and three Carnegie staff members, but cannot be completed yet as I await an important contribution from an indisposed co-author. Still, it should not be too long before that one is submitted — to be followed by baromount, and then finally superbaro.

So what’s happened here is that a perfectly innocent morphological description paper, based on a conference abstract and a 15-minute talk, has mutated into four substantial papers (of which, admittedly, only one is published so far).

The moral of this story

One moral is that I evidently have very little idea what I am going to work on at any given point in my career. As I was putting together the sidebar page on the Concrete Diplodocus paper, I stumbled across another sidebar page titled Mike’s open projects, which I made in 2020. It lists eight projects that I was going to work on. Of those, one (What do we mean by “cranial” and “caudal” on a vertebra?, Taylor and Wedel 2022) is complete; one (the superbaro project) has advanced but been interrupted by its three offspring papers; and the other six have pretty much not advanced at all (though I do still plan to do them all). Meanwhile, I have done a ton of work on projects that weren’t even on my radar back then, including pneumatic variation (Taylor and Wedel 2021) and finally putting a stake through the heart of neck incompleteness (Taylor 2022).

That’s the bad moral. But there is also a good moral. This is a nice example of what Matt wrote about way back in 2011, for Tutorial 12: How to find problems to work on. Once you actually get started working on something — anything — it will tend to sprout buds. And those buds can easily — too easily, sometimes — become new projects of their own. There is no such thing as a linear programme of research, at least not in my experience. Just an endlessly ramifying tree of fascinating areas that beg to be worked on.

References

 

Posted by Mike Taylor
Filed in Diplodocus, history, mounts, roadside dinos, Utah Field House of Natural History
3 Comments »

Exciting news for people who like history, the state of Utah, or sauropods

February 22, 2023

… and I’m guessing that if you read this blog, you like at least one of these things.

Today sees the publication of a paper that I’m particularly pleased with, partly because it’s so far outside my usual area: The Concrete Diplodocus of Vernal — a Cultural Icon of Utah (Taylor et al. 2023). Let’s jump in by taking a look at the eponymous concrete Diplodocus:

Taylor et al. (2023:figure 5). The completed outdoor Diplodocus mount in a rare color photograph. Undated (but between 1957 and 1989). Scanned by Eileen Carr for the J. Willard Marriot Digital Library, image ID 415530. Used by permission, Uintah County Library Regional History Center.

(On of the things I love about this photo is that it has the same 1950s energy as the Carnegie Tyrannosaurus mount that I posted a while back.)

This paper tells the neglected story of how the Utah Field House museum in Vernal acquired the original Carnegie Diplodocus molds in 1957, after they had languished, unloved and overlooked, in their Pittsburgh basement for forty years; how they were used to cast a Diplodocus from actual concrete (one part cement to three parts aragonite, for those who care); how the molds then went on a series of adventures, never actually yielding another complete skeleton, before being lost or destroyed; how the concrete cast stood for 30 years before the harsh Utah weather degraded it past the point of safety; how it was then used to make a fresh set of molds, and replaced by a new lightweight cast taken from those molds; and how the molds were then used to create a new generation of Diplodocus casts.

It’s a long and fascinating story with lots of twists and turns that I necessarily omitted from that summary — which is why it runs to 27 pages in the lavishly illustrated PDF. I urge you to go and read it for yourself: we wrote it to be an engaging story, and I hope it’s a pretty easy read. (My wife found it interesting, and she once literally fell asleep while I was running a talk to solicit her feedback, so that’s really something.)

Taylor et al. (2023:figure 3). Field House Museum director G. Ernest Untermann (left), and his wife, Staff Scientist Billie Untermann (right), grouting the cast dorsal vertebrae of the Field House’s concrete Diplodocus. 24 January 1957. Scanned by Aric Hansen for the J. Willard Marriot Digital Library, image ID 1086940. Used by permission, Uintah County Library Regional History Center.

This paper was submitted on 2 November 2022, so it’s taken less than five months to go through peer review, editorial processes, typesetting with four(!) rounds of page proofs and online publication. This of course is how it should always be — it’s a bit stupid that I am drawing attention to this schedule like it’s something extraordinary, but the truth is that it is extraordinary. At any rate that makes it fifteen times faster than my long-delayed (mostly my fault) paper on neck incompleteness (Taylor 2022).

I got so deeply into this paper when I was lead-authoring it that the phrase “the Concrete Diplodocus of Vernal” really started to echo around in my head. That is why the paper ends by expressing this wish:

Our dearest hope for this paper is that it inspires someone to create a Dungeons and Dragons module in which the Concrete Diplodocus of Vernal is a quest artifact with magical powers.

But Mike, you ask — how did you, a scientist, find yourself writing a history paper? It’s a good question, and one with a complicated answer. Tune in next time to find out!

References

 

 

Posted by Mike Taylor
Filed in 100% totally real, Diplodocus, history, mounts, roadside dinos, Utah Field House of Natural History
6 Comments »

Putative atlantal ribs of Diplodocus

November 23, 2022

Last time, I showed you a photo of the head and neck of the London Diplodocus and asked what was wrong. Quite a few of you got it right (including Matt when we were chatting, but I asked him not to give it away by posting a comment). The 100 SV-POW! dollars, with their cash value of $0.00, go to Orribec, who was the first to reply that the atlas (cervical 1) is upside-down.

Here is again, from the other side:

The Natural History Museum’s Carnegie Diplodocus cast, skull and anterior cervical vertebrae in left lateral view. Photograph by Mike Taylor.

I noticed this — when it seems the people putting up the skeleton did not, unless this is a deliberate joke — because I happened to be particularly tuned into atlas ribs at the time. You can see what appears a tiny rib hanging below the atlas, but no neural arch above it projecting up and back to meet the prezygapophyses of the axis (cervical 2). In fact the “cervical rib” on this left side is the neural arch of the right side, rotated 180 degrees about the axis of the neck.

Here’s how this should look, from the Carnegie Museum’s own Diplodocus:

The Carnegie Museum’s Diplodocus mount, skull and anterior cervical vertebrae in left lateral view. Photograph by Matt Lamanna.

In this picture, the atlas seems to be pretty much fused onto the axis, as seen in Gilmore (1936: figure 6) which Matt helpfully reproduced in Tutorial 36.

(Digression 1: you might think that this atlas is the real thing, since the Carnegie’s mount is the one with the real CM 84/94/307 material in it. But no: the atlas does not belong to any of those, which all lack this element. It seems to be a sculpture, but we can’t figure out what it’s based on.)

(Digression 2: you might notice that the London and Carnegie skulls are rather different. That’s because the London cast still has the original skull supplied in 1907, which is a sculpture based on CM 622 (rear) and USNM 2673 (the rest), while the Carnegie’s mount at some point had its skull replaced by a cast of CM 11161 — though no-one knows when.)

(Digression 3: the diplodocine originally catalogued as CM 662, on which the rear of the skull was based, was named as the holotype of a new species Diplodocus hayi by Holland (1924), traded to the Cleveland Museum of Natural History in 1956 where it was numbered CMNH 10670, then traded on the Houston Museum of Natural History in 1963 where istbecame HMNS 175, mounted in  Houston in 1975, remounted between 2013 and 2015, and finally moved to its own new genus Galeamopus by Tschopp et al. 2015. Yes, this stuff gets complicated.)

In fact, it’s amazing how much stuff we actually don’t know about these classic specimens, including the source of the atlas for both the Carnegie mount and the various casts — which are not the same. If only there was a single definitive publication that gathered everything that is known about these mounts. Oh well, maybe some day.

Now everyone knows that all the Carnegie Diplodocus mounts around the world were cast from the same molds, and so they all have the same altas <SCREEEECH> wait what?

The Muséum National d’Histoire Naturelle’s Carnegie Diplodocus cast, posterior part of skull and anterior cervical vertebrae in left lateral view. Photograph by Vincent Reneleau.

Here we are in Paris, and the atlas has these two honking great ribs. I have not seen these in any other Carnegie Diplodocus. I know they’re absent from the Berlin cast (thanks to Daniela Schwarz), from the Vernal re-cast (personal observation) and of course from the London cast. I would welcome observations (or even better, photos) from anyone who’s in a position to look at the Vienna, Bologna, Moscow, La Plata, Madrid or Mexico City casts.

So where did these atlas ribs come from? As with so much of this, no-one really knows. It’s especially mysterious as the Paris mount is supposed to be completely unchanged since its initial mounting. But some clue to the origin of the ribs in this mount is found in Holland (1906:249–250):

Accompanying the elements of the atlas sent to the writer for study by the kindness of Professor Osborn  [i.e. AMNH 969] are two bones, undoubtedly cervical ribs. They are both bones belonging on the right side of the centra. They are reported to have been found at the same place at which the atlas was found. The writer is inclined to think that the larger of these two bones (Fig. 20), was probably the rib of the atlas and indeed it requires but little effort to see that it might very well have served such a function, and that the smaller bone (Fig. 21) was the rib of the axis. Were the stump of the rib which remains attached to the axis in the Carnegie Museum, and which Mr. Hatcher has figured, removed, this smaller rib might take its place and would undoubtedly articulate very neatly to the facet

In case you’re too lazy to go and look at Holland’s illustrations for yourself, here they are.

The atlas rib:

The axis rib:

Holland went on:

In case the view entertained by the writer is correct, the form of the atlas and the axis with their attached ribs would be as given in the accompanying sketch (Fig. 22) rather than as given in the figure which has been published by Mr. Hatcher. Such a location of these parts has in its favor the analogy of the crocodilian skeleton.

Here is that composite atlas/axis complex:

(This arrangement with closely appressed atlas and axis ribs should ring a bell for anyone who’s looked much at croc necks, as for example in Taylor and Wedel 2013:figure 19.)

The atlas ribs on the Paris mount look a decent match for the one illustrated by Holland (1906:figure 20), so it seems a reasonable guess that they were sculpted based on that element. But that only leaves us with two more mysteries:

  1. Why do we see these atlas ribs only on the Paris cast, not in the Carnegie original or any of the other casts (that I know of)?
  2. Why does this cast have atlas ribs based on one of Holland’s elements, but not axis ribs based on the other?

Anyone?

References

 

Posted by Mike Taylor
Filed in atlas-axis complex, cervical, cervical ribs, Diplodocus, Natural History museum, necks, public galleries, stinkin' heads
7 Comments »

What’s wrong with this picture? No, really: what’s wrong?

November 21, 2022

Last Saturday I was at a wedding at Holy Trinity Brompton, a London church that is conveniently located a ten-minute stroll from the Natural History Museum. As I am currently working on a history paper concerning the Carnegie Diplodocus, I persuaded my wife, my eldest son and his fiancée to join me for a quick scoot around the “Dippy Returns” exhibition.

Here is a photo that I took:

Something is wrong here — and I don’t just mean the NHM exhibition’s stygian lighting.

Who can tell me what it is? $100 in SV-POW! Dollars(*) awaits the first person to get it right in the comments.

 

(*) Cash value: $0.00.

Posted by Mike Taylor
Filed in atlas-axis complex, cervical, cervical ribs, Diplodocus, Natural History museum, necks, public galleries, short, stinkin' heads
17 Comments »

Help SV-POW!: what happened to the original Carnegie Diplodocus molds?

August 21, 2022

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!”

References

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/

Posted by Mike Taylor
Filed in Carnegie Museum, Diplodocus, help SV-POW!, history, Houston Museum of Natural Science, mounts, National Museums Scotland, Rocky Mount Children's Museum, Utah Field House of Natural History
11 Comments »

Tyrannosaurus, Diplodocus, Apatosaurus and 1950s kids

May 20, 2022

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.

Posted by Mike Taylor
Filed in Apatosaurus, Carnegie Museum, Diplodocus, Dull analogue past, Gratuitously awesome images, public galleries, stinkin' theropods, Tyrannosaurus
20 Comments »

Tutorial 42: how to get a paper written

May 1, 2022

Yes, we’ve touched on a similar subject in a previous tutorial, but today I want to make a really important point about writing anything of substance, whether it’s a scientific paper, a novel or the manual for a piece of software. It’s this: you have to actually do the work. And the way you do that is by first doing a bit of the work, then doing a bit more, and iterating until it’s all done. This is the only way to complete a project.

Yes, this is very basic advice. Yes, it’s almost tautological. But I think it needs saying because it’s a lesson that we seem to be hardwired to avoid learning. This, I assume, is why so many wise sayings have been coined on the subject. Everyone has heard that “A journey of a thousand miles begins with a single step”, attributed to Lao Tzu in maybe the 5th Century BC. More pithily, I recently discovered that Williams Wordsworth is supposed to have said:

To begin, begin.

I love that. In just three words, it makes the point that there is no secret to be learned here, no special thing that you can do to make beginning easier. You just have to do it. Fire up your favourite word processor. Create a new document. Start typing.

And to Wordsworth’s injunction, I would add this:

To continue, continue

Because, again, there is no secret. You just have to do it.

Mounted skeleton of Diplodocus carnegii holotype CM 84 in the rare dorsal view.

At the moment I am working on four separate but related papers. Honestly, sometimes it’s hard even keeping them straight in my head. Sometimes I forget which one I am editing. It would be easy to get overwhelmed and … just not finish. I don’t mean it would be easy to give up: that would be a decision, and I don’t think I would do that. But if I listened to my inner sluggard, I would just keep on not making progress until the matter become moot.

So here is what I do instead:

  • I pick one of the papers, which is the one I’m going to work on that evening, and I try not to think too much about the others.
  • I figure out what needs to be in that paper, in what order.
  • I write the headings into a document, and I put an empty paragraph below each, which just says “XXX”. That’s the marker I use to mean “work needed here”.
  • I use my word-processor’s document-structuring facilities to set the style of each of the headings accordingly — 1st, 2nd or occasionally 3rd level.
  • I auto-generate a table of contents so I can see if it all makes sense. If it doesn’t, I move my headings around and regenerate the table of contents, and I keep doing that until it does make sense.
  • I now have a manuscript that is 100% complete except in the tiny detail that it has no content. This is a big step! Now all I have to do is write the content, and I’ll be finished.
  • I write the content, one section at a time. I search for “XXX” to find an unwritten section, and I write it.
  • When all the “XXX” markers have been replaced by text, the paper is done — or, at least, ready to be submitted.

Caveats:

First, that list makes it sound like I am really good at this. I’m not. I suck. I get distracted. For example, I am writing this blog-post as a distraction from writing a section of the paper I’m currently working on. I check what’s new on Tweetdeck. I read an article or two. I go and make myself a cup of tea. I play a bit of guitar. But then I go back and write a bit more. I could be a lot more efficient. But the thing is, if you keep writing a bit more over and over again, in the end you finish.

Second, the path is rarely linear. Often I’m not able to complete the section I want to work on because I am waiting on someone else to get back to me about some technical point, or I need to find relevant literature, or I realise I’m going to need to make a big digression. That’s fine. I just leave an “XXX” at each point that I know I’m going to have to revisit. Then when the email comes in, or I find the paper, or I figure out how to handle the digression, I return to the “XXX” and fix it up.

Third, sometimes writing a section blows up into something bigger. That’s OK. Just make a decision. That’s how I ended up working on these four papers at the moment. I started with one, but a section of it kept growing and I realised it really wanted to be its own paper — so I cut it out of the first one and made it its own project. But then a section of that one grew into a third paper, and then a section of that one grew into a fourth. Not a problem. Sometimes, that’s the best way to generate new ideas for what to work on: just see what come spiralling out of what you’re already working on.

None of these caveats change the basic observation here, which is simply this: in order to get a piece of work completed, you first have to start, and then have to carry on until it’s done.

 

Posted by Mike Taylor
Filed in Diplodocus, mounts, Tutorial, writing
5 Comments »

What’s the difference between a cervical and dorsal vertebra?

June 6, 2021

In mammals — certainly the most-studied vertebrates — regional differentiation of the vertebral column is distinct and easy to spot. But things aren’t so simple with sauropods. We all know that the neck of any tetrapod is made up of cervical vertebrae, and that the trunk is made up of dorsal vertebrae (subdivided into thoracic and lumbar vertebrae in the case of mammals). But how do we tell whether a given verebra is a posterior cervical or an anterior dorsal?

Here two vertabrae: a dorsal vertebra (D3) and a cervical vertebra (C13) from CM 84, the holotype of Diplodocus carnegii, modified from Hatcher (1901: plates III and VII):

It’s easy to tell these apart, even when as here we have only lateral-view images: the dorsal vertebra is tall, its centrum is short, its neural spine is anteroposteriorly compressed and its parapophysis is up on the dorsal half of the centrum; but the cervical vertebra is relatively low, its centrum is elongated, its neural spine is roughly triangular and its parapophysis hangs down well below the centrum (and has a cervical rib fused to it and the diapophysis).

But things get trickier in the shoulder region because, in sauropods at least, the transition through the last few cervicals to the first few dorsals is gradual — the vertebrae become shorter, taller and broader — and tends to have no very obvious break point. In this respect, they differ from mammals, in which the regional differentiation of the spinal column is more abrupt. (Although even here, things may not be as simple as generally assumed: for example, Gunji and Endo (2016) argued that the 1st thoracic vertebra of the giraffe behaves functionally like an 8th cervical.)

So here are those two vertebrae in context: the sequence D3 D2 D1 C15 C14 C13 in CM 84, the holotype of Diplodocus carnegii, modified from Hatcher (1901: plates III and VII):

Given that the leftmost is obviously a dorsal and the rightmost obviously a cervical, where would you place the break-point?

The most usual definition seems to be that the first dorsal vertebra is the first one that has a free rib, i.e. one not fused to the vertebra: in the illustration above, you can see that the three cervicals on the right all have their cervical ribs fused to their diapophyses and parapophyses, and the three dorsals on the left do not. This definition of the cervical/dorsal distinction seems to be widely assumed, but it is rarely explicitly asserted. (Does anyone know of a paper that lays it out for sauropods, or for dinosaurs more generally?)

But wait!

Hatcher (1903:8) — the same dude — in his Haplocanthosaurus monograph, writes:

The First Dorsal (Plate I., Fig. 1). […] That the vertebra now under consideration was a dorsal is conclusively shown not by the presence of tubercular and capitular rib facets showing that it supported on either side a free rib, for there are in our collections of sauropods, skeletons of other dinosaurs fully adult but, with the posterior cervical, bearing free cervical ribs articulating by both tubercular and capitular facets as do the ribs of the dorsal region. The character in this vertebra distinguishing it as a dorsal is the broadly expanded external border of the anterior branch of the horizontal lamina [i.e. what we would now call the centroprezygapophyseal lamina]. This element has been this modified in this and the succeeding dorsal, no doubt, as is known to be the case in Diplodocus to give greater surface for the attachment of the powerful muscles necessary for the support of the scapula.

Hatcher’s illustrations show this feature, though they don’t make it particularly obvious: here are the last two cervicals and the first dorsal, modified from Hatcher (1903:plate I), with the facet in question highlighted in pink: right lateral view at the top, then anterior, and finally posterior view at the bottom. (The facet is only visible in lateral and anterior views):

Taken at face value, Hatcher’s words here seem to imply that he considers the torso to begin where the scapula first lies alongside the vertebral column. Yet if you go back to the Diplodocus transition earlier in this post, a similar scapular facet is not apparent in the vertebra that he designated D1, and seems to be present only in D2.

Is this scapular-orientation based definition a widespread usage? Can anyone point me to other papers that use it?

Wilson (2002:226) mentions a genetic definition of the cervical/dorsal distinction

Vertebral segment identity may be controlled by a single Hox gene. The cervicodorsal transition in many tetrapods, for instance, appears to be defined by the expression boundary of the Hoxc-6 gene.

But this of course is no use in the case of extinct animals such as sauropods.

So what’s going on here? In 1964, United States Supreme Court Justice Potter Stewart, in describing his threshold test for obscenity, famously said “I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description, and perhaps I could never succeed in intelligibly doing so. But I know it when I see it.” Is that all we have for the definition of what makes a vertebra cervicals as opposed to dorsal? We know it when we see it?

Help me out, folks! What should the test for cervical-vs-dorsal be?

References

  • Gunji, Mego, and Hideki Endo. 2016. Functional cervicothoracic boundary modified by anatomical shifts in the neck of giraffes. Royal Society Open Science 3:150604. doi:10.1098/rsos.150604
  • Hatcher, Jonathan B. 1901. Diplodocus (Marsh): its osteology, taxonomy and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63 and plates I-XIII.
  • Hatcher, J. B. 1903b. Osteology of Haplocanthosaurus with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds; additional remarks on Diplodocus. Memoirs of the Carnegie Museum 2:1-75 and plates I-VI.
  • Wilson, Jeffrey A. 2002. Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136:217-276.

Posted by Mike Taylor
Filed in cervical, Diplodocus, dorsal, Haplocanthosaurus, help SV-POW!, ribs, Thinking it through
19 Comments »

Cross-sectional asymmetry of sauropod vertebrae

March 13, 2021

 

FIGURE 7.1. Pneumatic features in dorsal vertebrae of Barapasaurus (A–D), Camarasaurus (E–G), Diplodocus (H–J), and Saltasaurus (K–N). Anterior is to the left; different elements are not to scale. A, A posterior dorsal vertebra of Barapasaurus. The opening of the neural cavity is under the transverse process. B, A midsagittal section through a middorsal vertebra of Barapasaurus showing the neural cavity above the neural canal. C, A transverse section through the posterior dorsal shown in A (position 1). In this vertebra, the neural cavities on either side are separated by a narrow median septum and do not communicate with the neural canal. The centrum bears large, shallow fossae. D, A transverse section through the middorsal shown in B. The neural cavity opens to either side beneath the transverse processes. No bony structures separate the neural cavity from the neural canal. The fossae on the centrum are smaller and deeper than in the previous example. (A–D redrawn from Jain et al. 1979:pl. 101, 102.) E, An anterior dorsal vertebra of Camarasaurus. F, A transverse section through the centrum (E, position 1) showing the large camerae that occupy most of the volume of the centrum. G, a horizontal section (E, position 2). (E–G redrawn from Ostrom and McIntosh 1966:pl. 24.) H, A posterior dorsal vertebra of Diplodocus. (Modified from Gilmore 1932:fig. 2.) I, Transverse sections through the neural spines of other Diplodocus dorsals (similar to H, position 1). The neural spine has no body or central corpus of bone for most of its length. Instead it is composed of intersecting bony laminae. This form of construction is typical for the presacral neural spines of most sauropods outside the clade Somphospondyli. (Modified from Osborn 1899:fig. 4.) J, A horizontal section through a generalized Diplodocus dorsal (similar to H, position 2). This diagram is based on several broken elements and is not intended to represent a specific specimen. The large camerae in the midcentrum connect to several smaller chambers at either end. K, A transverse section through the top of the neural spine of an anterior dorsal vertebra of Saltasaurus (L, position 1). Compare the internal pneumatic chambers in the neural spine of Saltasaurus with the external fossae in the neural spine of Diplodocus shown in J. L, An anterior dorsal vertebra of Saltasaurus. M, A transverse section through the centrum (L, position 2). N, A horizontal section (L, position 3). In most members of the clade Somphospondyli the neural spines and centra are filled with small camellae. (K–N modified from Powell 1992:fig. 16.) [Figure from Wedel 2005.]

Here’s figure 1 from my 2005 book chapter. I tried to cram as much pneumatic sauropod vertebra morphology into one figure as I could. All of the diagrams are traced from pre-existing published images except the horizontal section of the Diplodocus dorsal in J, which is a sort of generalized cross-section that I based on broken centra of camerate vertebrae from several taxa (like the ones shown in this post). One thing that strikes me about this figure, and about most of the CT and other cross-sections that I’ve published or used over the years (example), is that they’re more or less bilaterally symmetrical. 

We’ve talked about asymmetrical vertebrae before, actually going back to the very first post in Xenoposeidon week, when this blog was only a month and a half old. But not as much as I thought. Given how much space asymmetry takes up in my brain, it’s actually weird how little we’ve discussed it.

The fourth sacral centrum of Haplocanthosaurus CM 879, in left and right lateral view (on the left and right, respectively). Note the distinct fossa under the sacral rib attachment on the right, which is absent on the left.

Also, virtually all of our previous coverage of asymmetry has focused on external pneumatic features, like the asymmetric fossae in this sacral of Haplocanthosaurus (featured here), in the tails of Giraffatitan and Apatosaurus (from Wedel and Taylor 2013b), and in the ever-popular holotype of Xenoposeidon. This is true not just on the blog but also in our most recent paper (Taylor and Wedel 2021), which grew out of this post.

Given that cross-sectional asymmetry has barely gotten a look in before now, here are three specimens that show it, presented in ascending levels of weirdness.

First up, a dorsal centrum of Haplocanthosaurus, CM 572. This tracing appeared in Text-fig 8 in my solo prosauropod paper (Wedel 2007), and the CT scout it was traced from is in Fig 6 in my saurischian air-sac paper (Wedel 2009). The section shown here is about 13cm tall dorsoventrally. The pneumatic fossa on the left is comparatively small, shallow, and lacks very distinct overhanging lips of bone. The fossa on the right is about twice as big, it has a more distinct bar of bone forming a ventral lip, and it is separated from the neural canal by a much thinner plate of bone. The fossa on the left is more similar to the condition in dorsal vertebrae of Barapasaurus or juvenile Apatosaurus, where as the one on the right shows a somewhat more extensive and derived degree of pneumatization. The median septum isn’t quite on the midline of the centrum, but it’s pretty stout, which seems to be a consistent feature in presacral vertebrae of Haplocanthosaurus.

 

Getting weirder. Here’s a section through the mid-centrum of C6 of CM 555, which is probably Brontosaurus parvus. That specific vert has gotten a lot of SV-POW! love over the years: it appears in several posts (like this one, this one, and this one), and in Fig 19 in our neural spine bifurcation paper (Wedel and Taylor 2013a). The section shown here is about 10cm tall, dorsoventrally. In cross-section, it has the classic I-beam configuration for camerate sauropod vertebrae, only the median septum is doing something odd — rather than attaching the midline of the bony floor of the centrum, it’s angled over to the side, to attach to what would normally be the ventral lip of the camera. I suspect that it got this way because the diverticulum on the right either got to the vertebra a little ahead of the one on the left, or just pneumatized the bone faster, because the median septum isn’t just bent, even the vertical bit is displaced to the left of the midline. I also suspect that this condition was able to be maintained because the median septa weren’t that mechanically important in a lot of these vertebrae. We use “I-beam” as a convenient shorthand to describe the shape, but in a metal I-beam the upright is as thick or thicker than the cross bits. In contrast, camerate centra of sauropod vertebrae could be more accurately described as a cylinders or boxes of bone with some holes in the sides. I think the extremely thin median septum is just a sort of developmental leftover from the process of pneumatization.

EDIT 3 days later: John Whitlock reminded me in the comments of Zurriaguz and Alvarez (2014), who looked at asymmetry in the lateral pneumatic foramina in cervical and dorsal vertebrae of titanosaurs, and found that consistent asymmetry along the cervical column was not unusual. They also explicitly hypothesized that the asymmetry was caused by diverticula on one side reaching the vertebrae earlier than diverticula on other other side. I believe they were the first to advance that idea in print (although I should probably take my own advice and scour the historical literature for any earlier instances), and needless to say, I think they’re absolutely correct.

Both of the previous images were traced from CTs, but the next one is traced from a photo of a specimen, OMNH 1882, that was broken transversely through the posterior centrum. To be honest, I’m not entirely certain what critter this vertebra is from. It is too long and the internal structure is too complex for it to be Camarasaurus. I think an apatosaurine identity is unlikely, too, given the proportional length of the surviving chunk of centrum, and the internal structure, which looks very different from CM 555 or any other apatosaur I’ve peered inside. Diplodocus and Brachiosaurus are also known from the Morrison quarries at Black Mesa, in the Oklahoma panhandle, which is where this specimen is from. Of those two, the swoopy ventral margin of the posterior centrum looks more Diplodocus-y than Brachiosaurus-y to me, and the specimen lacks the thick slab of bone that forms the ventral centrum in presacrals of Brachiosaurus and Giraffatitan (see Schwarz and Fritsch 2006: fig. 4, and this post). So on balance I think probably Diplodocus, but I could easily be wrong.

Incidentally, the photo is from 2003, before I knew much about how to properly photograph specimens. I really need to have another look at this specimen, for a lot of reasons.

Whatever taxon the vertebra is from, the internal structure is a wild scene. The median septum is off midline and bent, this time at the top rather than the bottom, the thick ventral rim of the lateral pneumatic foramen is hollow on the right but not on the left, and there are wacky chambers around the neural canal and one in the ventral floor of the centrum. 

I should point out that no-one has ever CT-scanned this specimen, and single slices can be misleading. Maybe the ventral rim of the lateral foramen is hollow just a little anterior or posterior to this slice. Possibly the median septum is more normally configured elsewhere in the centrum. But at least at the break point, this thing is crazy. 

What’s it all mean? Maybe the asymmetry isn’t noise, maybe it’s signal. We know that when bone and pneumatic epithelium get to play together, they tend to make weird stuff. Sometimes that weirdness gets constrained by functional demands, other times not so much. I think it’s very seductive to imagine sauropod vertebrae as these mechanically-optimized, perfect structures, but we have other evidence that that’s not always true (for example). Maybe as long as the articular surfaces, zygapophyses, epipophyses, neural spine tips, and cervical ribs — the mechanically-important bits — ended up in the right places, and the major laminae did a ‘good enough’ job of transmitting forces, the rest of each vertebra could just sorta do whatever. Maybe most of them end up looking more or less the same because of shared development, not because it was so very important that all the holes and flanges were in precisely the same places. That might explain why we occasionally get some really odd verts, like C11 of the Diplodocus carnegii holotype.

That’s all pretty hand-wavy and I haven’t yet thought of a way to test it, but someone probably will sooner or later. In the meantime, I think it’s valuable to just keep documenting the weirdness as we find it.

References

Posted by Matt Wedel
Filed in camarasaurs, cervical, cross sections, diplodocids, Diplodocus, dorsal, Haplocanthosaurus, pneumaticity, sacral, Saltasaurus, titanosaur
8 Comments »

Hey, look, sauropod vertebrae!

January 15, 2021

It’s been a minute, hasn’t it?

Up top, C10 and C11 of Diplodocus carnegii CM 84, from Hatcher (1901). Below, C9 and C10 of Apatosaurus louisae CM 3018, from Gilmore (1936). The Diplodocus verts are in right lateral view but reversed for ease of comparison, and the Apatosaurus verts are in left lateral view. Both sets scaled to the same cumulative centrum length. Just in case you forgot that apatosaurines are redonkulous.

References

  • Hatcher, John Bell. 1901. Diplodocus (Marsh): its osteology, taxonomy, and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63.
  • Gilmore, Charles Whitney. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300.

Posted by Matt Wedel
Filed in Apatosaurus, cervical, diplodocids, Diplodocus
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