Last time, we reviewed what’s known about Jensen’s three giant sauropods based on published papers (and one abstract). This time, I want to talk a bit about what Matt and I have discovered, and intend to publish when we get around to it.

The Three Baro Jacket

It all followed on from our work on Barosaurus (which for now remains available only as a preprint, becalmed as it is in the peer-review doldrums — mostly my fault). Because of that, we were on the alert for Barosaurus material when we were travelling around Utah in Spring of 2016, and one of the first things we locked onto at the Brigham Young University’s Museum of Paleontology (BYU) was this:

We’ve been informally calling this “Three Baro Jacket”, or “3BJ” for short. But if we’re being formal, it’s specimen BYU 20815, being field jacket 3GR from BYU Locality 601 (The Jensen/Jensen quarry at Jensen, Utah), excavated in 1966. It also has an accession number, JJ/66 (which I didn’t realise was different from the specimen number).

Here it is being winched out of the ground at the Jensen/Jensen quarry, back in 1966 (photo courtesy of Brooks Britt):

This jacket contains — as our name for it suggests — three Barosaurus cervicals. The easiest way to see them is in 3D, using this red-cyan anaglyph, which shows the structure of the block much more informatively than the flat photo above:

(Do you have red-cyan anaglyph glasses? If not get some. They are dirt cheap, and will show you a whole world of morphology. For example, Amazon will send you ten pairs for $3.26, so you can keep two at home and two at work, and give half a dozen to your friends.)

For those stuck in the 2D world, these interpretive drawings should help to pick out the vertebrae from the matrix: they show individually the three vertebrae that we arbitrarily designated as A, B and C in that order.

Characters of Barosaurus cervicals

We spent some time looking pretty closely at these vertebra to figure out what they were — after all, the jacket wasn’t presented to us as “Here are some Barosaurus cervicals”. As we did so, we kept comparing the 3BJ vertebrae with photos we’d taken of the YPM and AMNH Barosaurus cervicals, and published illustrations. And as we did this, we discovered a whole set of distinctive characteristics of Barosaurus cervicals. We will properly describe and illustrate these characters another time, but to briefly summarise:

  • 1. Centra very long relative to vertebral height (measured at the posterior articular surface). This one will come as no surprise.
  • 2. Neural spine low and fairly smooth in profile.
  • 3. Postzygapophyses set forward slightly from posterior margin of centrum — as opposed to set well forward in brachiosaurs, or overhanging the posterior margin in apatosaurs.
  • 4. Parapophysis set much further forward than diapophysis, so that the cervical rib loop projects anteroventrally from the diapophysis.
  • 5. Cervical rib loop very thin anteroventrally (and lateromedially).
  • 6. Distinct hollow “thumb groove” between prezygapophyseal facet and pre-epipophysis.
  • 7. “U”-shaped notch in dorsal view where prezygapophyseal rami meet.
  • 8. Prezygapophyseal rami have two “faces” at right angles: one facing dorsomedially (bearing the prezgapophyseal facet), one facing dorsolaterally.
  • 9. Prezyagpophyseal rami very broad.
  • 10. Process projecting posteriorly from diapophysis.
  • 11. Prezyadiapophyseal lamina sweeps out smoothly to diaphophysis in dorsal view.

(These characters are all illustrated in our 2016 SVPCA talk: check the slides if you want to get a better handle on what we’re describing here. The reason I listed them in the slightly odd order above is so you can easily match them up with the slides.)

Now these vertebrae are well worthy of proper study and description in their own right, and we do plan to give them the attention they deserve. But for today’s story, they have done their part.

What is BYU 9024?

Now, here’s the thing. Literally a couple of yards away from the Three Baro Jacket in BYU collections sits the single longest vertebra of anything ever discovered: our old friend BYU 9024 (what Jensen called BYU 5003), which was originally assigned to Ultrasaurus (Jensen 1985), then reassigned to Supersaurus (Jensen 1987).

Mike compares Jensen’s sculpture of the big Supersaurus cervical BYU 9024 with the actual fossil.

And the more we looked at Barosaurus cervicals, then looked at BYU 9024, then looked back at Barosaurus, the more convinced we became that BYU 9024 is itself a Barosaurus cervical.

You would not immediately think this to look at the bone, as it’s pretty smashed up, and very difficult to interpret from photos, but this anaglyph will help:

As we discussed before, the posterior end looks much taller dorsoventrally than it should, because the postzygapophysis is folded upwards and the ventrolateral processes folded down.

Here’s what we see in BYU 9024 in terms of the characters we picked out from the 3BJ vertebrae. First, in left lateral view, with the characters highlighted in green:

  • 1. Centra very long relative to vertebral height (measured at the posterior articular surface).
  • 2. Neural spine low and fairly smooth in profile.
  • 3. Postzygapophyses set forward slightly from posterior margin of centrum.
  • 4. Parapophysis set much further forward than diapophysis, so that the cervical rib loop projects anteroventrally from the diapophysis.
  • 10. Process projecting posteriorly from diapophysis.

Now in anterodorsal view, with dorsal to the left:

  • 7. “U”-shaped notch in dorsal view where prezygapophyseal rami meet.
  • 8. Prezygapophyseal rami have two “faces” at right angles: one facing dorsomedially (bearing the prezgapophyseal facet), one facing dorsolaterally.
  • 9. Prezyagpophyseal rami very broad.

(It’s not easy to tell from this photo, but the broken-off area of flattish bone highlighted in the circle is part of the dorsolaterally-facing aspect of the prezygapophyseal ramus, where is it merging into the prezygadiapophyseal lamina.)

Three of the characters we saw in 3BJ we couldn’t determine in BYU 9024, due to breakage:

  • 5. Cervical rib loop very thin anteroventrally (and lateromedially).
  • 6. Distinct hollow “thumb groove” between prezygapophyseal facet and pre-epipophysis.
  • 11. Prezyadiapophyseal lamina sweeps out smoothly to diaphophysis in dorsal view.

But the morphology that’s preserved is certainly compatible with all of these. There are also a couple more characters in this vertebra that indicate that it’s Barosaurus, which we were not able to isolate in any of the 3BJ vertebrae:

  • A pair of posteroventrally directed accessory laminae radiating from the part of the centrum surface medial to the diapophysis. (These may be homologous with PCDLs but they seem to come out from under the PODL.)
  • It lacks paired foramina on the ventral surface separated by a midline ridge, as seen in Apatosaurus and WDC Supersaurus. (Thanks to David Lovelace from drawing our attention to that one in a comment on the last post!)

No one or two of these characters is a slam-dunk in isolation. But when you put them all together, they leave us pretty much 100% satisfied that BYU 9024 is a Barosaurus cervical.

How big was the BYU 9024 animal?

Before we say anything at all about this, please first hear our standard disclaimer: any size estimate based on a single bone is necessarily going to be wildly speculative, and could easily be a long way out in either direction.

That said, here’s the thinking behind our best guess.

First, what is the serial position of BYU 9024? We’d like to determine this by comparing with the cervical series of AMNH 6341, which is pretty well preserved — but unfortunately it has never been adequately illustrated and is now impossible to photograph as it is entombed below a walkway in the AMNH public gallery. Here’s the best published illustration, from McIntosh (2005:figure 2.1):

We judge it most similar to C9 or maybe C10, based largely on neural spine bifurcation and general proportions when corrected for distortion.

In AMNH, C9 is 685 mm long and C10 is 737 mm long (McIntosh 2005:table 2.1). Since BYU 9024 is 1370 mm in length, it is exactly twice as long as the C9 and 1.86 times as long as the C10.

I think I speak for all right-thinking people when I say holy crap.

If our identification of BYU 9024 as a C9 of Barosaurus is correct, then we are talking about an animal twice as large in linear dimension as the AMNH specimen whose cast looms over the rotunda (and the one at the Natural History Museum of Utah, which by eye is about the same size). Since the neck of the AMNH specimen is 8.5 m long (Wedel 2007:206–207), that would mean that the neck alone of BYU 9024 would have been 17 m long: longer than most complete sauropods and substantially taller than the mounted Giraffatitan skeleton in Berlin. The length of the whole animal is harder to predict, even if we assume isometry, but if Paul’s (2010:189) length estimate of 27 m for regular Barosaurus is correct, we’re probably looking at a total length exceeding 50 m.

This animal would, other things being equal, be eight times as massive (2 × 2 × 2) as the AMNH Barosaurus. There aren’t a lot of Barosaurus mass estimates out there, but Wedel (2005:217–221) did a lot of careful work to arrive at about 12 tonnes for the Diplodocus carnegii holotype CM 84, which is about the same size as the AMNH Barosaurus. If that’s right, then the BYU 9024 animal might have massed about 8 × 12 = 96 tonnes, which puts it right up there among the heaviest known sauropods: probably the heaviest represented by extant fossils, as the other strong contenders for that title are Maraapunisaurus and Bruhathkayosaurus, both known only from illustrations of now-destroyed specimens.

[UPDATE, the next day: see the next post for more on the serial position of the vertebra and the size of the animal.]

We presented most of this reasoning in our 2016 SVPCA talk, whose abstract and slides are online. (Sadly, there is no recording of the actual talk.)

Tune in for the post after that as we (finally!) reach the part promised by the title of this series, and consider where Jensen’s Big Three genera stand today.

 

References

  • Jensen, James A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45(4):697–709.
  • Jensen, James A. 1987. New brachiosaur material from the Late Jurassic of Utah and Colorado. Great Basin Naturalist 47(4):592–608.
  • McIntosh, John S. 2005. The genus Barosaurus Marsh (Sauropoda, Diplodocidae). pp. 38-77 in: Virginia Tidwell and Ken Carpenter (eds.), Thunder Lizards: the Sauropodomorph Dinosaurs. Indiana University Press, Bloomington, Indiana. 495 pp.
  • Paul, Gregory S. 2010. Dinosaurs: a Field Guide. A. & C. Black Publishers ltd. London, UK. 320 pp.
  • Wedel, Mathew J. 2005. Postcranial skeletal pneumaticity in sauropods and its implications for mass estimates. pp. 201-228 in Wilson, J. A., and Curry-Rogers, K. (eds.), The Sauropods: Evolution and Paleobiology. University of California Press, Berkeley
  • Wedel, Mathew J. 2007. Postcranial pneumaticity in dinosaurs and the origin of the avian lung. Ph.D dissertation, Integrative Biology, University of California, Berkeley, CA. Advisors: Kevin Padian and Bill Clemens. 290 pages.
Advertisements

It’s time to revisit everyone’s favourite trio of apocryphal super-sized sauropods! (Yes, we’ve talked about this before, but only very briefly, and that was nearly eleven years ago. Things have moved on since then.)

John Sibbick’s classic artwork showing three giant sauropods, including two of Jensen’s three. On the left is Seismosaurus Gillette 1991, which is not directly relevant to today’s post. In the middle is the brachiosaur Ultrasaurus, and on the right the diplodocid Supersaurus. Poor, unloved Dystylosaurus doesn’t get a look-in — perhaps because this was drawn before that name had been announced?

Here’s the story so far …

1. Jensen’s discoveries

In a series of expeditions beginning in April 1972, following a tip from uranium prospectors Eddie and Vivian Jones, Jim Jensen found numerous massive sauropod fossils in the Dry Mesa quarry, southwest Colorado. The Supersaurus pelvis at least was still in the ground as late as August 1972 (George 1973b:51–52) and the excavations continued into 1982 (Jensen 1985:697).

Eschewing such pedestrian venues as Science, Nature or indeed the Journal of Vertebrate Paleontology, Jensen first told the world about these finds in the popular press. The oldest published work I have that mentions them is Jean George’s (1973b) piece in Reader’s Digest, condensed from the same author’s piece in the Denver Post’s Empire Magazine earlier that year (George 1973a), which I have not been able to obtain.

“‘Supersaurus,’ as we shall call him, now awaits an official name and taxonomic classification”, wrote George (1973b:53) — but the piece does not mention the names “Ultrasaurus” or “Dystylosaurus” and I’ve not been able to determine when those informal names became known to the world. (Can anyone help?) We do know that Jensen was informally using the name “Ultrasaurus” as early as 1979 (Curtice et al. 1996:87).

Anyway, for reasons that have never been very clear, Jensen concluded that the remains represented not one, not two, but three gigantic new genera: a diplodocid, which he named “Supersaurus”; a brachiosaurid, which he named “Ultrasaurus”; and an unidentifiable which he named “Dystylosaurus”. All these names were informal at this point, like “Angloposeidon” and “The Archbishop”.

2. Kim’s accidental Ultrasaurus

After Jensen had been using these names informally for some years, Kim (1983) named an indeterminate Korean sauropod as Ultrasaurus tabriensis. Based on the abstract (the only part of the paper in English, apart from the figure captions), Kim was aware of Jensen’s dinosaurs: “Judging by the large size of the ulna the animal may belong to the sauropod dinosaur, which is much bigger than Supersaurus. A new name Ultrasaurus tabriensis is proposed for the convenience of the further study.” While this does not quite go so far as to say that Kim considered the ulna to belong to the same genus as Jensen’s brachiosaur, it seems unlikely that he was aware of Supersaurus but not of Ultrasaurus, and landed independently on the latter name by coincidence.

Either way, in naming his species, Kim inadvertently preoccupied Jensen’s chosen genus name, with conseqences that we shall see below. By all accounts, the material the Kim described is in any case indeterminate, and the genus is generally considered a nomen nudum (e.g. Olshevsky 1991:139, Glut 1997:1001).

Kim 1983, plate 1, parts 1-3, illustrating the proximal portion of the huge “ulna” that the name Ultrasaurus tabriensis was founded on. As is apparent, this is actually the proximal end of a humerus, meaning that the animal is rather less large than Kim supposed — although the 42 cm width across the proximal end is still nothing to be sniffed at. It is about 71% the width of the 59 cm-wide humerus of the Giraffatitan brancai paralectotype MB.R.2181 (previously HMN SII).

Two years after this, and presumably unaware of Kim’s paper or incorrectly assuming his informal use of the name “Ultrasaurus” gave him priority, Jensen published a formal account of his finds, naming them (Jensen 1985). Unfortunately, while the paper does contain formal nomenclatural acts that are valid according to the rules of the ICZN, Jensen did not explain his reasoning for the creation of the new genera, and his selection of type material was problematic, as we shall see below. Also, the specimen numbers that he used have been superseded — I do not know why, but my guess would be that he re-used numbers that were already in use for other specimens, so his own material had to be given new numbers.

3. Jensen’s three sauropods

The following three genera (with their type species) were named, in this order:

1. Supersaurus vivianae, based on the holotype BYU 9025 (BYU 5500 of his usage), a scapulocoracoid measuring 2.44 m in length. To this, he referred an even larger scapulocoracoid whose length he gives as 2.70 m (though Curtice and Stadtman 2002:39 found that this length to be due to optimistic reconstruction); an ischium; either one or two mid-caudal vertebrae (his paper contradicts itself on this); and a sequence of 12 articulated caudal vertebrae. Unfortunately, Jensen’s use of specimen numbers for most of these referred elements is inconsistent, but he is at least consistent in referring to the second scapulocoracoid as BYU 5501.

Supersaurus vivianae holotype scapulocoracoid BYU 9025, photographed at the North American Museum of Natural Life. The exhibit text reads: “Supersaurus scapula and coracoid. This is the actual Supersaurus bone that the world saw when the announcement was made of the new animal’s discovery in 1972. The scapula lay in the ground for five more years, waiting for the collection of other fossils that lay in the path of excavation. The flatness of the bone presented a challenge to “Dinosaur Jim” Jensen, who had to figure out a way to get the bone safely out of the ground. He finally accomplished this by cutting the scapula into three pieces. In 1988, Cliff Miles, Brian Versey and Clark Miles prepared the bone for study. It is still one of the largest dinosaur bones known in the world. Specimen on load from Brigham Young University’s Earth Science Museum. Late Jurassic/Early Cretaceous (about 144 million years ago)

2. Ultrasaurus macintoshi, based on the holotype BYU 9044 (BYU 5000 of his usage), a dorsal vertebra measuring 1.33 m in height. To this, he referred BYU 9462 (BYU 5001 of his usage), a scapulocoracoid measuring 2.7 m in length; BYU 9024 (BYU 5003 of his usage), a huge cervical vertebra; and an anterior caudal vertebra.

Ultrasaurus macintoshi holotype dorsal vertebra BYU 9044, photographed at the North American Museum of Natural Life. (It’s incredibly hard to photograph well because it’s behind reflective glass.)

3. Dystylosaurus edwini, based on the holotype BYU 4503 (BYU 5750 of his usage), a dorsal vertebra. He did not refer any other material to this taxon, and considered it “Family indeterminate” commenting that it “no doubt represents a new sauropod family”. Poor Dystylosaurus has always been the unloved member of this group, and pretty much ignored in the literature aside from the Curtice & Stadtman (2002) synonymisation paper discussed below.

Dystylosaurus edwini holotype BYU 4503, a diplodocoid anterior dorsal vertebra.

In a subsequent paper, Jensen (1987:600–602) removed the big cervical BYU 9024 (BYU 5003 of his usage) from Ultrasauros and reassigned it to Diplodocidae. The text of this paper never refers it to Supersaurus vivianae in particular, but it is illustrated and captioned as belonging to that taxon (Jensen 1987:figures 7A-B, 8C), and this assignment is generally assumed to have been meant.

When Jensen became aware of Kim’s (1983) preoccupation of the name Ultrasaurus, he recognised that his own genus needed a new name. At his suggestion, Olshevsky (1991) erected the replacement name Ultrasauros (with a single-letter spelling difference) for Jensen’s taxon based on the dorsal vertebra BYU 9044. We will use this revised spelling hereon, and the taxon Ultrasaurus Kim 1983 is of no further interest to this story.

The relevant extract from Olshevsky (1991:139).

4. Curtice’s synonymies

This was how things stood, with Jensen’s assignment of the material to his three new genera standing unchallenged, until Brian Curtice came on the scene in the mid 1990s. In a series of three publications (two papers, one abstract), he first synonymised Ultrasauros with Supersaurus, then Dystylosaurus also with Supersaurus, and finally (tentatively) Supersaurus itself with Barosarus. If Curtice’s suggestions were all correct, then there were no new sauropods from Jensen’s work in the the Dry Mesa quarry, just a lot of Barosaurus material.

Was he right? We’ll now consider each of the three publications in turn.

First, Ultrasauros. Jensen had always considered this genus to be a brachiosaurid due to the morphology of the scapulocoracoid BYU 9462 — and indeed this element does seem to be brachiosaurid. Unfortunately, he did not found the taxon on this element, but on the dorsal vertebra BYU 9044. Curtice et al. (1996) re-examined this element, and argued convincingly that it was not an anterior dorsal from a brachiosaurid, as Jensen had thought, but a posterior dorsal from a diplodocid. Since its neural spine morphology matches that of the first preserved sacral spine (S2) of the Supersaurus sacrum, and since it was found between the two Supersaurus scapulocoracoids, Curtice et al. (1996:94) considered BYU 9044 to be a vertebra of Supersaurus (belonging to the holotype individual), and therefore concluded that Ultrasauros was a junior subjective synonym of Supersaurus. They inferred that the referred Ultrasauros scapulocoracoid BYU 9462 therefore did not belong to the same species as the type, since it was brachiosaurid, and referred it to Brachiosaurus sp.

We consider all of Curtice et al.’s (1996) arguments well-founded and convincing, and agree with their conclusions. As a result, both spellings of Jensen’s brachiosaurid genus are now discarded: Ultrasaurus as a nomen dubium, and Ultrasauros as a junior synonym.

Curtice et al. (1996:figure 2). “Uncrushed” Supersaurus vivianae caudal dorsal, BYU 9044, right lateral view.

A few years later, Curtice and Stadtman (2002) took aim at Dystylosaurus. Jensen had argued that it was unique because of the paired centroprezygapophyseal laminae that supported each prezygapophysis from below — and it was from this feature than the genus took its name. But Curtice and Stadtman pointed out that this supposedly unique feature is in fact almost ubiquitous in diplodocids. Because it, too, was found between the two Supersaurus scapulae (close to the Ultrasaurus dorsal), Curtice and Stadtman referred it, too, to Supersaurus, thereby collapsing all three of Jensen’s taxa into one. This argument, too, is well supported and has been generally accepted.

Finally, in a sole-authored abstract, Curtice (2003) hedged about whether he considered Supersaurus to be Barosaurus. I will quote directly, as the line of reasoning is vague and difficult to summarise:

The question of is Supersaurus truly a distinct genus from Barosaurus is now testable. The former Dystylosaurus dorsal vertebra provides an autapomorphy for Supersaurus, that being a strongly reduced bifid neural spine on dorsal four. This loss of bifidity is important for in all other diplodocids the neural spine is still deeply bifurcated on dorsal four. Only Barosaurus has a reduction in cleft depth that far forward in the dorsal column. Supersaurus has all but lost the cleft, more closely resembling the sixth dorsal vertebra of Barosaurus than the fourth.

It is disappointing that this abstract never became a more rigorously argued paper, because the conclusion here is highly equivocal. Curtice appears to be saying that Supersaurus is distinct from Barosaurus — but only on the basis of bifidity reducing two vertebrae more anteriorly in Supersaurus. In other words, he seems to be suggesting that the two taxa are indisinguishable aside from this rather minor difference.

At any rate, this speculation in a conference abstract has generally been ignored, and Supersaurus considered a valid and distinct genus.

5. Jimbo the WDC Supersaurus

In 2008, Lovelace et al. (2008, duh) described WDC DMJ-021, a new specimen of Supersaurus vivianae at the Wyoming Dinosaur Center that is known informally as “Jimbo”. (Confusingly, they refer to the Supersaurus holotype scapulocoracoid by yet a third specimen number, BYU 12962; but we will continue to use BYU 9025 here. It is possible that BYU 12962 is the revised specimen number of the referred scapulocoracoid, not the holotype.)

Lovelace et al. (2008) did not justify in detail their referral of Jimbo to Supersaurus. The closest the come is this brief passage on page 529–530:

While a scapula is not known for WDC DMJ-021, other elements are identical to axial elements referred to the type individual of Supersaurus. Referral of all material is supported by relative position within their respective quarries (Curtice and Stadtman 2001; Lovelace 2006), size of the skeletal elements, and congruence of phylogenetically significant diplodocid characters between the scapula and referred material.

All of this is kind of weaselly. What it amounts to is this: vertebrae are “identical” to those referred to the BYU Supersaurus (but not really, as we’ll see), and the elements are really big, and the Supersaurus holoype scap comes out in about the same place as Jimbo in a phylogenetic analysis if you code them up separately. This is weak sauce, and I would really have liked to see a much more explicit “Jimbo shares synapomorphies X, Y and Z with BYU Supersaurus” section.

Among the ways in which the justification for this assignment disappoints is that the presacrals that are described as “identical” to the BYU elements are not at all well preserved (Lovelace et al. 2008:figures 3D–E, 4A, 5A): in particular C13, presumably the best preserved cervicals as it is the only one illustrated, is missing the condyle, prezygapophyses and neural spine. It’s not possible to be sure in light of the small monochrome illustrations in the paper, but it does not seem likely that these elements can be reliably assessed as identical to the BYU cervical.

Lovelace et al. (2008:figure 3). Lateral views of cervical vertebrae from A, Diplodocus carnegii (Hatcher 1901); B, Barosaurus lentus (Lull 1919); C, Apatosaurus louisae (Gilmore 1936); D and E, Supersaurus vivianae; demonstrating pneumatic modifications of centra. Supersaurus has the least amount of modification with minimal size for pneumatopores. Internal structure is similar to that seen in other diplodocids (Janensch, 1947). Left lateral view of Cv.13 (D, missing the condyle, prezygapophyses and neural spine; length of incomplete centra 94cm). E, cross section through Cv.11, 5cm posterior of the diapophysis.

The big surprise in the Jimbo paper is that in the phylogenetic analysis (Lovelace et al. 2008:figure 14), the compound BYU+WDC Supersaurus is recovered as an apatosaurine, the sister taxon to Apatosaurus, rather than as a diplodocine as had been assumed in previous studies due to its resemblance to the diplodocine Barosaurus.

The huge specimen-level phylogenetic analysis of diplodocoids by Tschopp et al. (2015) corroborated Lovelace et al’s (2008) referral of the WDC specimen to Supersaurus vivianae, as the two species were sister groups in all most parsimonious trees, with quite strong character support (Tschopp et al. 2015:187). But it placed the Supersaurus clade at the base of Diplodocinae, not within Apatosaurinae as Lovelace et al. (2008) had found.

This, then, was the state of play when Matt and I started to work on Supersaurus during the 2016 Sauropocalypse: Ultrasauros and Dystylosaurus had both been sunk into Supersaurus, and the WDC specimen had been referred to the same species.

Next time, we’ll look what Matt and I found in Utah, and what we think it means for Supersaurus and its friends.

 

References

  • Curtice, Brian D. 2003. Two genera down, one to go? The potential synonomy [sic] of Supersaurus with Barosaurus. Southwest Paleontological Symposium 2003, Guide to Presentations. Mesa Southwest Museum, January 25 2003. Unpaginated.
  • Curtice, Brian D. and Kenneth L. Stadtman. 2001. The demise of Dystylosaurus edwini and a revision of Supersaurus vivianae. Western Association of Vertebrate Paleontologists and Mesa Southwest Museum and Southwest Paleontologists Symposium, Bulletin 8:33-40.
  • Curtice, Brian D., Kenneth L. Stadtman and Linda J. Curtice. 1996. A reassessment of Ultrasauros macintoshi (Jensen, 1985). M. Morales (ed.), “The continental Jurassic”. Museum of Northern Arizona Bulletin 60:87–95.
  • George, Jean. 1973a. Supersaurus, the biggest brute ever. Denver Post, Empire Magazine. May 13, 1973.
  • George, Jean. 1973b. Supersaurus, the biggest brute ever. Reader’s Digest (June 1973):51–56.
  • Glut, Donald F. 1997. Dinosaurs: the Encyclopedia. McFarland & Company Inc., Jefferson. 1076 pp.
  • Jensen, James A. 1985. Three new sauropod dinosaurs from the Upper Jurassic of Colorado. Great Basin Naturalist 45(4):697–709.
  • Jensen, James A. 1987. New brachiosaur material from the Late Jurassic of Utah and Colorado. Great Basin Naturalist 47(4):592–608.
  • Kim, Hang-mook. 1983. Cretaceous dinosaurs from South Korea. Journal of the Geological Society of Korea 19(3):115–126.
  • Lovelace, David M., Scott A. Hartman and William R. Wahl. 2008. Morphology of a specimen of Supersaurus (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny. Arquivos do Museu Nacional, Rio de Janeiro 65(4):527–544.
  • Olshevsky, George. A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2:1–196.
  • 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

 

Okay, so here on the Best Coast it’s not technically my birthday for another 3 hours, but SV-POW! runs on England time, and at the SV-POW! global headquarters bunker it’s already June 3. Oh, and tomorrow Brian and I are driving to New Mexico to look for Cretaceous monsters with Andrew McDonald and crew, and I won’t be advantageously situated for blogging. So here’s my Favorite. Card. EVAR:

Next to Charles Knight, the Czech painter Zdeněk Burian was arguably the most influential and important of the early palaeoartists. His dinosaurs tend to have a stately quality that’s very much at odds with our post-Dinosaur Renaissance sensibilities, but which has its own charm. Here’s arguably his most famous (and incorrect) piece, the snorkelling brachiosaurs:

The reason I mention him now is that I recently stumbled across the Paleo Porch site containing decent-quality images of his artworks. For some reason, Burian’s work always seems to appear in low-quality, small-size scans which do nothing to mitigate his tendency to use muted colours and low contrasts. So it’s nice to see his work looking relatively bold and clear.

Here’s his Brontosaurus, too:

There’s a ton we could criticise about both of these pieces; but we don’t have to do that. Instead, let’s just bask in the sheer dinosaurosity of these classic pieces.

Since the rather surprising apppointment of Mike Eisen as the new Editor-in-Chief of eLife, I’ve found myself thinking about this journal again. At its inception in 2012, it was explicitly intended to be the open-access alternative that would “compete with publishing powerhouses such as Nature, Science and Cell“.

A few years ago, in an article about eLife‘s £25M additional cash injection from its three original funders, Nature News reported a doubling down on its original mission, citing an interview with founding Editor-in-Chief Randy Schekman:

But it won’t, he says, establish other open-access journals that accept more papers and have lower selectivity — a strategy that some organizations, such as the Public Library of Science, or PLoS, has turned to in an attempt to shore up finances. “We have no interest in creating other lesser journals with lower standards,” he says.

This makes no sense to me.

Four years ago, I was already saying “It’s a real shame that the eLife people have fallen into the impact-chasing trap and show no interest in running an eLife megajournals.” Now that eLife’s funding is running out and it’s having to introduce APCs, it makes even less sense to refuse to run a review-for-correctness-only journal alongside its flagship.

I do see why some people think it’s desirable to have an OA alternative to Science and Nature. But I can’t understand at all why they won’t add a second, non-selective journal — an eLIFE ONE, if you will — and automatically propagate articles to it that are judged “sound but dull” at eLIFE proper (or eLIFE Gold, as they may want to rename it). Way back in I think 2012 I spoke separately to Randy Schekman and executive director Mark Patterson about this: both of them were completely uninterested then, and it seems that’s still the case.

This is why Mike Eisen’s appointment is such a surprise. In a recent interview regarding this appointment, he commented “Our addiction to high-impact factor journals poisons hiring and funding decisions, and distorts the research process” — which I agree with 100%. But then why has he taken on a role in a journal that perpetuates that addiction?

We can only hope that he plans to change it from within, and that eLife ONE is lurking just beyond the horizon.

 

Appendix

This isn’t a new drum for me to be banging. Way back when eLife launched in 2012, I left a comment on its Reviewer’s Charter. Seven years on, all the comments seem to have vanished (I hate it when that happens), but happily for posterity I saved what I wrote. Here it is:

This charter is an excellent start. But I would like to see a Guideline Zero that lays out what the purposes (plural) of peer-review are. I see three very distinct purposes, and much of the frustration with peer-review comes from reviews that blur these.

1. Assessing whether the paper is sound, i.e. does it express a coherent argument that is backed up by data?

2. Assessing “importance” or “impact”, i.e. is the paper likely to be seen as a significant advance in its field, and to gather many citations?

3. Helping the author improve the paper by constructively suggesting changes that can be made without altering the fundamental nature of the paper.

All of these are important contributions, but they are quite separate and should be kept so. In category 3, for example, if a reviewer suggests that a sentence would be easier to parse if changed around, that should certainly not affect the gatekeeping decisions in categories 1 and 2.

PLoS ONE has shown the importance of separating caterories 1 and 2. In that journal, and those that now emulate it, the “impact” criterion is explicitly ignored, and all good papers are published however important or unimportant they are considered to be. (This means, among other things, that replication studies are welcome.)

This inclusive strategy is not appropriate for all journals — I understand that eLife is actively aiming to reject most submissions on “impact” criteria, in the hope of attaining prestige similar to that of Science and Nature. But even in journals that evaluate for impact, it’s important to separate the two assessment criteria. One important practical implication of this separation is that a subsequent high-volume “eLife ONE” journal could publish all eLife submissions that passed criterion 1 but failed criterion 2 without the need for further review.

I don’t think there was ever a response to that comment back in the day (though I can’t be certain due to the comments’ having vanished.) I hope that’s set to change under the new regime.

 

You know the drill. For ground-level Diplodocus, go here, for Apatosaurus, go here.

Hello, ladies!

March 28, 2019

To my shock, I find that we seem never to have posted Bob Nicholls’ beautiful sketch Hello, ladies! on SV-POW!. His recent tweet reminded me about this piece, so here it is!

Like so many classic sauropod sketches, this was executed during a mammal-tooth talk at SVPCA: this one back in 2013, the year of our first Barosarus talk. (Our second was in 2016.)

Bob’s sketch shows speculative sexual display behaviour. We have no direct evidence for (or against) such behaviour; but while we don’t believe sexual selection was the main reason for sauropods evolving long necks, it seems inevitable that long necks evolved for other purposes would be exapted for sexual display.

I always love Bob’s sketches — in fact, for most palaeoartists, I tend to like their sketches more than their finished pieces. Among the many things about this one that make me jealous is all the females in the background admiring the male: the economy of line where Bob can not only summon up a perfectly cromulent diplodocid head in a few strokes, but imbue it with a sense of being inquisitive about the display. It’s magical.

 


Whatever happened to that 2013 Barosaurus project?, you may ask.

Well, the first thing that happened is that after we submitted the abstract, entitled Barosaurus revisited: the concept of Barosaurus (Dinosauria: Sauropoda) is based on erroneously referred specimens, we realised that there was a tiny, tiny mistake in our work. So by the time I gave the talk at the actual conference, the title slide was this:

Then you will recall we did an efficient job of converting the conference presentation into a manuscript, which we submitted as a preprint less than a month after the conference. The preprint quickly garnered amazingly helpful comments, which we used to extensively revise the manuscript.

For reasons we don’t understand, there was a three-year delay before we got it submitted for peer-review in 2016; but when we did finally submit, we did it in the confident hope that it would sail through peer-review, having already been extensively reviewed and revised.

But it was not to be. When we got the reviews back, they asked for a ton of changes, and that process was just too dispiriting to face having already made a ton of changes based on the first set of comments just prior to the submission. So the tedious process got back-burnered, and the suddenly three more years passed.

The upshot is that I still need to handle the reviews on the 2nd version of the paper, and shove the blasted thing through the peer-review process. I will, to be frank, be glad to get it out of my POOP chute, so I can think about other things — not least, the 2016 Barosaurus project.