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/

We have many times been in the position of having the reference for a paper and wanting to find the full text. But I think this is a first: I have the full text of a paper, and I want to find the reference!

The paper is a short one — just two pages — so I will reproduce it in its entirely right here in the blog-post:

As you can see, it’s by Billie R. Untermann and her husband G. Ernest Untermann — both important figure in the history of the Utah Field House museum whose history they were chronicling. The report doesn’t have a running header with the journal title, date, volume or issue, or even page number. We know nothing except that we can guess the date is 1970 or 1971 because of the closing statement that “1971 will be one of its greatest years”.

How can the source be tracked down?

I tried asking around on Twitter, but that didn’t pan out. A couple of people there suggested the G. Ernest Untermann papers collection, at Archives West. But John Foster kindly went through those boxes without turning it up, so our best hope struck out. John also had the had the University of Utah library go through the State Parks newsletters, which seemed the most likely venue, but again without success.

So over to you, dear readers. Can anyone come up with a route to track down the source of this report? To whoever comes up with the reference, I offer the shiny prize of formal acknowledgement in a forthcoming paper.

 

I have long intended to write a paper entitled Why Elephants Are So Small, as a companion piece to Why Giraffes Have Short Necks (Taylor and Wedel 2013). I’ve often discussed this project with Matt, usually under the acronym WEASS, and its substance has come up in the previous post, and especially Mickey Mortimer’s comment:

I think it would be interesting to read a study on that — the order in which various factors restrict body size without transformative adaptations. Similarly, what the differences would be for an aquatic animal like a whale.

That is exactly what the WEASS project was supposed to consist of: a list of many candidate limitations on how big animals can get, some rough attempt to quantify their Big-O behaviour, some discussion of which factors seems to limit the sizes of modern terrestrial animals, and how dinosaurs (especially sauropods) worked around those limitations.

(Whales are different. I have in my mind a half-formed notion for a third paper, completing the trilogy, with a title along the lines of Why Whales Are Dirty Cheaters.)

What are those candidate limitations? Off the top of my head:

Biomechanical:

  • Bone strength
  • Cartilage strength
  • Cartilage thickness
  • Muscle strength
  • Nerve length and conduction time

Metabolic:

  • Blood pressure: column height and capillary length
  • Lung capacity
  • Tracheal dead space
  • Digestive efficiency
  • Metabolic overheating

Those are just some of the physical limits. There is anecdotal evidence that elephants are not very close to their mechanical limits in their usual behaviour: they could get bigger, and still work mechanically. (Follow the link at the start of this paragraph. You will thank me.)

There are plenty of other factors that potentially limit organism size, including:

Behavioural:

  • Feeding rate
  • Ability to navigate dense environments
  • Predator avoidance with limited athleticism
  • Difficulties in mating

Ecological:

  • Territory requirement
  • Time taken to reach reproductive maturity
  • Reproductive rate
  • Birth size
  • Lack of selection pressure: when there are no predators bigger than a lion, why would elephants need to evolve larger size?

I’m sure I am missing loads. Help me out!

I am haunted by something Matt wrote a while back when we were discussing this — talking about how alien sauropods are, and how easily we slip into assuming mammal-like paradigms.

We are badly hampered by the fact that all of the 250kg+ land animals are mammals. We only get to see one way of being big, and it’s obviously not the best way of being big. Our perceptions of how hard it is to be big are shaped by the animals that are bad at it.

So having written this blog post, I am wondering whether it’s time to breathe life back into this project, started in 2009 and repeatedly abandoned.

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!

Matt and I are writing a paper about Barosaurus cervicals (yes, again). Regular readers will recall that the best Barosaurus cervical material we have ever seen was in a prep lab for Western Paleo Labs. We have some pretty good photos, such as this one:

Barosaurus cervical vertebra lying on its right side in anterodorsal view (i.e. with dorsal to the left), showing the distinctive shape of the prezygapophyseal rami.

The problem is that this specimen was privately owned at the time we saw it, and so far as we know it still is. So according to all standard procedures, we should consider it unavailable to science until such time as it is deposited in an accredited museum. (I was pretty sure the SVP has an explicit policy to this effect, but I couldn’t find it on the site. Can anyone?)

So what should we do? All the possible courses of action seem unfortunate.

1. We could go ahead and include photos, drawings and descriptions of these vertebrae in the paper — but that would violate community norms by building an argument on observations that cannot be in general be replicated by other researchers. (For all we know, these vertebrae are now decorating Nicolas Cage’s pool room.)

2. We could omit these vertebrae from the paper, but use the information we gained from examining them in formulating our diagnostic criteria for Barosaurus cervicals — but this would also not really be replicable, plus it would have that horrible “we know something that you don’t” quality.

3. We could act as though these vertebrae do not exist, or as though we had never seen them, writing the paper based only on our observations of inferior material and of the good AMNH 6341 that is not accessible for study or photography — but that would make our characterisation of Barosaurus cervical morphology less helpful than it could be.

4. We could refrain from publishing on Barosaurus cervicals at all until such time as these vertebrae, or similarly well-preserved ones, are available to study at accredited institutions — but that would simply deprive the world of an interesting and exciting study.

Is there a fifth path that we have not seen? And if not, which of these four is the least objectionable?

I was looking more closely at the turkey skeleton from my recent post, and zeroed in on the last two dorsal (= thoracic) vertebrae. They articulate very well with each other and with the first vertebra of the sacrum, with the centra and zygapophyses both locking in so that there can only have been very little if any movement between them in life. Here they are, in right lateral view:

Last two dorsal (= thoracic) vertebrae of a mature domestic turkey Meleagris gallopavo domesticus, in right lateral view.

Before we move on, it’s worth clicking through to the full-size version of this image and wondering at both the quality of modern phone cameras (a Pixel 3a in this case) and the variety of textures on these little bones. There is smooth, finished bone on the sides of the neural spines; very fine pits and bumps on the zygapophyseal facets where the thin layer of hyaline cartilage attached; rougher texture in the parapophyseal facets where thicker cartilage attached; and very rough texture on the ends of the transverse processes, where there was relatively thick cartilage.

And there is, unsurprisingly in a bird, pneumaticity everywhere. In the more anterior vertebra alone (to the right) the photo shows pneumatic openings (from bottom to top) low on the centrum (below the parapophysis), high on the centrum (below the lateral process),  in the hollow between the lateral process, the posyzyg and the centrum, on the lateral surface of the prezygapophyseal ramus, and on the rear surface of the lateral process. There are others that are obscured in this photo, including on top of the lateral process where it meets the neural spine. Here they are, pointed out for you (with the hidden one shown translucently):

Last two dorsal (= thoracic) vertebrae of a mature domestic turkey Meleagris gallopavo domesticus, in right lateral view. Pneumatic openings on penultimate vertebra highlighted with red lines; obscured opening above lateral process shown as translucent.

OK, that was the B-movie. Now to the main feature. The next photo shows the same two vertebrae, folded away from each other so that we see the anterior face of the posterior vertebra (on the left) and the posterior face of the anterior vertebra (on the right).

Last two dorsal (= thoracic) vertebrae of a mature domestic turkey Meleagris gallopavo domesticus. Left: last dorsal vertebra in anterior view; right: penultimate dorsal vertebra in posterior view.

Again, do click through to see the exquisite detail, especially the complex of pneumatic features on the anterior face of the neural spine of the last dorsal (on the left) and on the posterior face of the left lateral process of the penultimate dorsal (on the right).

And … in the articular facets of the centra?

Seriously, what the heck is going on here? It doesn’t make sense  that there would be pneumatic openings in articular surfaces, because by definition something else (in this case the adjacent vertebra) is abutted hard up against then, so there is no way for a diverticulum to get in. For the same reason, you don’t get vascular foramina in articular surfaces because there is no way to get an artery in there. And there is no hint in these vertebrae of channels along either articular surface that diverticula or arteries could  possibly have laid in.

And yet, there those big openings are. What are they?

I discussed this with Matt, in case it’s Well Known Phenomenon that I’d somehow not heard about but it seems it is not. What we know for sure is that these openings are present, and that they are not mechanical damage inflicted during preparation. So what are they?

What else even is there for them to be? What penetrates bone apart from diverticula and blood vessels? Nerves follow the blood vessels, so it can’t be nerves in the absence of blood vessels.

By the way, there are similar but smaller openings in the posterior face of the last dorsal (the one on the right in the photo), but none anywhere else along the postcervical column: not on the anterior surface of the penultimate dorsal, not on the front or back of the sacrum, and not in any of the other dorsals.

One possibility we considered is that the vertebrae were locked together in life and that a pneumatic space inside the centrum of the last dorsal worked right through into the penultimate one. But that doesn’t work: the openings are not aligned. Also, those in the penultimate dorsal are definitely blind (i.e. they do not connect to deeper internal air-spaces) and those in the last dorsal probably are, too.

We do not know what is going on here.

Help us! Is this kind of thing common in turkeys? Have people seen it in other taxa? Do we know what it is?

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.

I have several small ordered sequences of data, each of about five to ten elements. For each of them, I want to calculate a metric which captures how much they vary along the sequence. I don’t want standard deviation, or anything like it, because that would consider the sequences 1 5 2 7 4 and 1 2 4 5 7 equally variable, whereas for my purposes the first of these is much more variable.

Here is a matric that I think does what I want, and will allow me to compare different sequences for variability-along-the-sequence.

For the n-1 pairs along the sequence of n elements, I take the difference (absolute value, so always positive) between elements i and i+1. Then I average all those differences. Then I divide the result by the average of the values themselves, to normalise for magnitude.

Some example calculations:

  • For the sequence 1 5 2 7 4, the differences are 4 3 5 3, for a total of 15 and an average of 3.75. The average of the values is 1+5+2+7+4 = 19/5 = 3.8, which gives me a metric of 3.75/3.8 = 0.987.
  • For the sequence 1 2 4 5 7, the differences are 1 2 1 2, for a total of 6 and an average of 1.5. The average of the values is again 3.8, which gives me a metric of 1.5/3.8 = 0.395.
  • So the first sequence is 0.987/0.395 = 2.5 times as sequentially variable as the second sequence.
  • And for the sequence 10 20 40 50 70 (which is the same as the previous one, but all values ten times greater), the differences are 10 20 10 20, for a total of 60 and an average of 15. The average of the values is 38, which gives me a metric of 15/38 = 0.395, the same as before — which is as it should be.

And now, my question! Does this metric, or something similar, already exist? If so, what is it called? Or if I should be using something else instead, what is it?

(It happens that my sequences are the aspect ratios of the cotyles of consecutive vertebrae, but that’s not important: whatever metric we land on should work for any sequences.)

Taylor 2015: Figure 8. Cervical vertebrae 4 (left) and 6 (right) of Giraffatitan brancai lectotype MB.R.2180 (previously HMN SI), in posterior view. Note the dramatically different aspect ratios of their cotyles, indicating that extensive and unpredictable crushing has taken place. Photographs by author.

A couple of months ago, I asked for your help in compiling a list of all known complete sauropods necks. This has gone really well, and I want to thank everyone who chipped in, and all the various authors I have contacted for details as a result.

My next step is to take the raw data in the Google spreadsheet that I have been maintaining, and write it up as prose for the paper that I am shortly going to resubmit, having first done so back in 2015. And I thought it would make sense to draft that section here on SV-POW!, so I can get any further feedback before I finalize it for the manuscript.

Young and Zhao (1972:figure 3). Mamenchisaurus hochuanensis holotype CCG V 20401 as is occurred in the field.

So here goes: any additional comments at this stage will be welcome!


Unambiguously complete necks are known from published accounts of only a few sauropod specimens. In chronological order of description, the following specimens were found with their necks complete and articulated, and have been adequately described:

  • CM 11338, a referred specimen of Camarasaurus lentus described by Gilmore (1925). This is a juvenile specimen, and thus does not fully represent the adult morphology. (McIntosh et al. 1996:76 claim that this specimen is the holotype, but this is not correct: YPM 1910 is the holotype — see below.)
  • CM 3018, the holotype of Apatosaurus louisae, described by Gilmore (1936). The neck was separated from the torso but articulated from C1–C15, though the last three cervicals were badly crushed: see below for details.
  • CCG V 20401, the Mamenchisaurus hochuanensis holotype, described by Young and Zhao (1972). Each vertebra is broken in half at mid-length, with the posterior part of each adhering to the anterior part of the its successor; and all the vertebrae are badly crushed in an oblique plane.
  • ZDM T5402, a Shunosaurus lii referred specimen, described in Chinese by Zhang (1988), with English figure captions. Figure 22 depicts the atlas. Unlike the holotype T5401, this specimen is mature.
  • BYU 9047, the Cathetosaurus lewisi holotype, described by Jensen (1988). (Jensen incorrectly gives the specimen number as BYU 974.) This specimen was redescribed, and the species referred to Camarasaurus, by McIntosh et al. (1996). Although all 12 cervicals are present, “10–12, particularly 12, have suffered such severe damage that it is impossible to restore them” (McIntosh et al. 1996:76).
  • MACN-N 15, the holotype of Amargasaurus cazaui MACN-N 15, described by Salgado and Bonaparte (1991) who desribed “22 presacral vertebrae articulated with each other and attached to the skull and sacrum, relatively complete” (Salgado & Bonaparte 1991:335, translated.
  • ZDM 0083, the holotype of Mamenchisaurus youngi, described in Chinese by Ouyang and Ye (2002) with English figure captions. Figure 14 depicts the atlas and axis.
  • MUCPv-323, the holotype of Futalognkosaurus dukei, initially described by Calvo et al. 2007a and redescribed by Calvo et al. 2007b. The neck was found in two articulated sections which fit together without needing additional vertebrae in between (Jorge O. Calvo, pers. comm., 2021).
  • SSV12001, the holotype of Xinjiangtitan shanshanesis, described by Zhang et al. (2018). The original description of this specimen by Wu et al. 2013 included only the last two cervicals, which were the only ones that had been excavated at that time.

A few additional specimens are known to have complete and articulated necks, but have not yet been described:

  • USNM 13786, a referred subadult specimen of Camarasaurus lentus recently mounted at the Smithsonian. The specimen “was almost completely buried before the sinews had allowed the bones to separate” (letter from Earl Douglass to William J. Holland, 22 August 1918), and photographs kindly supplied by Andrew Moore show that the atlas was preserved.
  • MNBH TIG3, the holotype of Jobaria tiguidensis. Sereno et al. (1999:1343) assert that this species has 12 cervicals in all and say “One articulated neck was preserved in a fully dorsiflexed, C-shaped posture”. Sereno (pers. comm., 2021) confirms that the articulated neck is MNBH TIG3
  • SMA 002, referred to Camarasaurus sp. Tschopp et al. (2016), in a description of its feet, say that this specimen “lacks only the vomers, the splenial bones, the distal end of the tail, and one terminal phalanx of the right pes. The bones are preserved in three dimensions and in almost perfect articulation”.
  • MAU-Pv-LI-595, the “La Invernada” Titanosaur. Filippi et al. (2016) give a very brief account in an abstract. Filippi, pers. comm, 2021) says that the entire preserved specimen was articulated.
  • MAU-Pv-AC-01, an unnamed titanosaur mentioned in abstracts by Calvo et al. (1997) and Coria and Salgado (1999). The specimen was found in perfect articulation from skull down to the last caudal vertebrae (Rodolfo Coria, pers. comm., 2021).

The first cervical (the atlas) in sauropods is very different in form from the other vertebrae, and small and fragile. Consequently it is easily lost. Some further specimens have necks that are complete and articulated from C2 (the axis) backwards:

  • MB.R.4886, the holotype of Dicraeosaurus hansemanni, described by Janensch (1929), has a neck that complete and well preserved from C2 to C12 (the last cervical). Janensch referred to this as “specimen m” and writes “It was found articulated from the 19th caudal vertebra to the 9th cervical vertebra inclusive. The proximal part of the neck from the 8th cervical vertebra up to the axis was bent ventrally and lay at right angles to the distal part of the neck.” (Janensch 1929:41).
  • PMU 233, the holotype of Euhelopus zdanskyi, described by Wiman (1929) as “exemplar a” and redescribed by Wilson and Upchurch (2009).
  • ZDM T5401, the subadult holoype of Shunosaurus lii, described in Chinese by Zhang et al 1984. The quarry map (Zhang et al. 1984:figure 1) suggests that the atlas is missing.
  • MCT 1487-R, informally known as “DGM Series A”, described by Powell (2003). Gomani (2005:9) summarises as “12 cervical vertebrae, except the atlas, preserved in articulation with three proximal dorsal vertebrae”.
  • GCP-CV-4229, the holotype of Spinophorosaurus nigerensis, described by Remes et al. (2009). The specimen was found in very good condition and well articulated from C2 to C13, the last cervical. The atlas seems to be missing (Remes, pers. comm., 2021.

One other sauropod is complete from the first cervical, but probably not to the last:

  • MOZ-Pv1232, the holotype of Lavocatisaurus agrioensis, described by Canudo et al. (2018). This is complete from C1-C11. Canudo’s guess is that this is complete neck (Canudo, pers. comm, 2021), but the specimen doesn’t demand that conclusion and no known eusauropod has fewer than 12 cervicals.

Other sauropod specimens have necks that are complete and articulated from further back in the cervical sequence:

  • YPM 1910, Camarasaurus lentus, a mounted specimen described by Lull (1930). The neck is complete from C2 or C3, Lull was uncertain which.
  • SMA 0004, Kaatedocus siberi, described by Tschopp and Mateus (2012). Cervicals 3-14 are preserved.
  • AODF 888 (informally “Judy”), probably referrable to Diamantinasaurus, briefly described by Poropat et al. (2019). Preserved from C3 or maybe C4. “One posterior cervical (XIII or XIV) found several metres from articulated series, but appears to slot nicely into the gap between the articulated cervical series and the unprepared thoracic section, which might include at least one additional cervical (XIV or XV)” (Poropat, pers. comm. 2021).

Several necks are probably nearly complete, but it is not possible to knew due to their not being found in articulation:

  • CM 84, the holotype of Diplodocus carnegii, described by Hatcher (1901). C2–C15 are preserved, though not all in articulation; C11 may be an intrusion: see below for details.
  • ZDM T5701, the holotype of Omeisaurus tianfuensis, described by He et al. (1988). The neck was not articulated (He et al. 1988:figure 1), and was missing “two elements or so” (He et al. 1988:120).
  • QJGPM 1001, the holotype of Qijianglong guokr, described by Xing et al. (2015). On page 8, the authors say “The axis to the 11th cervical vertebra were fully articulated in the quarry. The atlas intercentrum and the 12th–17th cervical vertebrae were closely associated with the series.”
  • MNBH TIG9, a referred specimen of Jobaria tiguidensis. Wilson (2012:103) writes that this specimen “includes a partially articulated series of 19 vertebrae starting from the axis and extending through the mid-dorsal vertebrae.”
  • MNBH TIG6, another referred specimen of Jobaria tiguidensus, which has not been mentioned in the literature. Sereno (pers. comm., 2021) says that it is “a subadult partial skeleton with excellent neck” and that “the sequence was articulated from C2–11. Most of the ribs were attached as well.”

At the time of writing, the Paleobiology Database (https://paleobiodb.org/) lists more than 270 sauropod species. The nine unambigously complete and articulated necks therefore represent only one in 30 known sauropod species.

Note. The Jobaria tiguidensis individuals previously had specimen numbers beginning MNN, but the Musee National du Niger changed its name to Musée National Boubou Hama and the specimen numbers have changed with it.

Today marks the one-month anniversary of my and Matt’s paper in Qeios about why vertebral pneumaticity in sauropods is so variable. (Taylor and Wedel 2021). We were intrigued to publish on this new platform that supports post-publication peer-review, partly just to see what happened.

Taylor and Wedel (2021: figure 3). Brontosaurus excelsus holotype YPM 1980, caudal vertebrae 7 and 8 in right lateral view. Caudal 7, like most of the sequence, has a single vascular foramen on the right side of its centrum, but caudal 8 has two; others, including caudal 1, have none.

So what has happened? Well, as I write this, the paper has been viewed 842 times, downloaded a healthy 739 times, and acquired an altmetric score 21, based rather incestuously on two SV-POW! blog-posts, 14 tweets and a single Mendeley reader.

What hasn’t happened is even a single comment on the paper. Nothing that could be remotely construed as a post-publication peer-review. And therefore no progress towards our being able to count this as a peer-reviewed publication rather than a preprint — which is how I am currently classifying it in my publications list.

This, despite our having actively solicited reviews both here on SV-POW!, in the original blog-post, and in a Facebook post by Matt. (Ironically, the former got seven comments and the latter got 20, but the actual paper none.)

I’m not here to complain; I’m here to try to understand.

On one level, of course, this is easy to understand: writing a more-than-trivial comment on a scholarly article is work, and it garners very little of the kind of credit academics care about. Reputation on the Qeios site is nice, in a that-and-two-bucks-will-buy-me-a-coffee kind of way, but it’s not going to make a difference to people’s CVs when they apply for jobs and grants — not even in the way that “Reviewed for JVP” might. I completely understand why already overworked researchers don’t elect to invest a significant chunk of time in voluntarily writing a reasoned critique of someone else’s work when they could be putting that time into their own projects. It’s why so very few PLOS articles have comments.

On the other hand, isn’t this what we always do when we write a solicited peer-review for a regular journal?

So as I grope my way through this half-understood brave new world that we’re creating together, I am starting to come to the conclusion that — with some delightful exceptions — peer-review is generally only going to happen when it’s explicitly solicited by a handling editor, or someone with an analogous role. No-one’s to blame for this: it’s just reality that people need a degree of moral coercion to devote that kind of effort to other people’s project. (I’m the same; I’ve left almost no comments on PLOS articles.)

Am I right? Am I unduly pessimistic? Is there some other reason why this paper is not attracting comments when the Barosaurus preprint did? Teach me.

References