December 10, 2014
Today sees the description of Aquilops americanus (“American eagle face”), a new basal neoceratopsian from the Cloverly Formation of Montana, by Andy Farke, Rich Cifelli, Des Maxwell, and myself, with life restorations by Brian Engh. The paper, which has just been published in PLOS ONE, is open access, so you can download it, read it, share it, repost it, remix it, and in general do any of the vast scope of activities allowed under a CC-BY license, as long as we’re credited. Here’s the link – have fun.
Obviously ceratopsians are much more Andy’s bailiwick than mine, and you should go read his intro post here. In fact, you may well be wondering what the heck a guy who normally works on huge sauropod vertebrae is doing on a paper about a tiny ceratopsian skull. The short, short version is that I’m here because I know people.
The slightly longer version is that OMNH 34557, the holotype partial skull of Aquilops, was discovered by Scott Madsen back in 1999, on one of the joint Cloverly expeditions that Rich and Des had going on at the time (update: read Scott’s account of the discovery here). That the OMNH had gotten a good ceratopsian skull out of Cloverly has been one of the worst-kept secrets in paleo. But for various complicated reasons, it was still unpublished when I got to Claremont in 2008. Meanwhile, Andy Farke was starting to really rock out on ceratopsians at around that time.
For the record, the light bulb did not immediately go off over my head. In fact, it took a little over a year for me to realize, “Hey, I know two people with a ceratopsian that needs describing, and I also know someone who would really like to head that up. I should put these folks together.” So I proposed it to Rich, Des, and Andy in the spring of 2010, and here we are. My role on the paper was basically social glue and go-fer. And I drew the skull reconstruction – more on that in the next post.
Anyway, it’s not my meager contribution that you should care about. I am fairly certain that, just as Brontomerus coasted to global fame on the strength of Paco Gasco’s dynamite life restoration, whatever attention Aquilops gets will be due in large part to Brian Engh’s detailed and thoughtful work in bringing it to life – Brian has a nice post about that here. I am very happy to report that the three pieces Brian did for us – the fleshed-out head that appears at the top of this post and as Figure 6C in the paper, the Cloverly environment scene with the marauding Gobiconodon, and the sketch of the woman holding an Aquilops – are also available to world under the CC-BY license. So have fun with those, too.
Finally, I need to thank a couple of people. Steve Henriksen, our Vice President for Research here at Western University of Health Sciences, provided funds to commission the art from Brian. And Gary Wisser in our scientific visualization center used his sweet optical scanner to generate the hi-res 3D model of the skull. That model is also freely available online, as supplementary information with the paper. So if you have access to a 3D printer, you can print your own Aquilops – for research, for teaching, or just for fun.
Next time: Aquilöps gets röck döts.
Farke, A.A., Maxwell, W.D., Cifelli, R.L., and Wedel, M.J. 2014. A ceratopsian dinosaur from the Lower Cretaceous of Western North America, and the biogeography of Neoceratopsia. PLoS ONE 9(12): e112055. doi:10.1371/journal.pone.0112055
November 14, 2014
So how did the YPM come to make such a monstrosity? What was it based on? Tune in next time for the surprising details!
I told him at the time that I’d soon get around to writing a post. But before I did, he wrote a post on this himself: Bully for Camarasaurus. And it’s excellent. Go and read it!
I don’t have a lot to add to what Ben has written, except regarding this:
What Marsh had instead [when restoring the skull for his 1891 “Brontosaurus” reconstruction] were a few fragmentary bits of Camarasaurus cranial material, plus a snout and jaw (USNM 5730) now considered to be Brachiosaurus.
Here’s what Marsh came up with:
But what of the supposed Brachiosaurus skull that he used as a reference? It was finally described 107 years later by Carpenter and Tidwell (1998), in a paper that helpfully also lays out the history behind it. Here’s how it looks:
The skull was found by a crew under the supervision of M. P. Felch in the western part of his Quarry 1, Garden Park, Colorado. Felch reported it to O. C. Marsh in a letter of 8 September 1883. It was found by a meter-long cervical vertebra that probably belonged to Brachiosaurus “which was destroyed during attempts to collect it” (McIntosh and Berman 1975:196). [Of course, Felch and Marsh could hardly have been expected to identify this vertebra correctly, as Brachiosaurus would not be discovered and named for another twenty years (Riggs 1903), and the nature of its neck would not become apparent until Janensch (1914) described the related brachiosaurid Giraffatitan (= “Brachiosaurus“) brancai.]
The Felch skull, along with other material from the quarry, was shipped to Marsh at Yale in October of that year, and was initially assigned the specimen number YPM 1986. At that time it was only partially prepared, hence the rather poor resemblance between the restored version above and Marsh’s hypothetical “Brontosaurus” [= Apatosaurus] skull that was based on it.
It’s notable that Holland (1915) was quite certain that this was not a skull of Brontosaurus, and that a Diplodocus-like skull found with the A. louisae holotype belonged to it. It’s worth reading the skull section of his paper to see just how solid his reasoning was. And it’s extraordinary to think that Osborn’s power, all the way over in New York, was so great that he was able to successfully bully Holland, 370 miles away in Pittsburgh, into not putting the evidently correct skull on the Carnegie Museum’s Apatosaurus mount. That mount remained sadly headless until after Holland’s death.
Aaanyway, YPM 1986 was pretty much ignored after Marsh’s abuse of it as a reference for the Brontosaurus reconstruction’s skull. After Marsh’s death in 1899, much of the material collected by Felch was transferred to the Smithsonian (US National Museum of Natural History). The skull was among these specimens, and so was re-catalogued as USNM 5730.
As so often, it was Jack McIntosh who rediscovered this skull and recognised its true affinities. Some time after his tentative identification of the skull as pertaining to Brachiosaurus (presumably on the basis of its resemblance to that of Giraffatitan), Carpenter borrowed the skull, had it more fully prepared, wrote the description, and had a restored model constructed from casts of the preserved elements and models of the missing ones.
Carpenter and Tidwell (1998:fig. 2) also handily showed the restored Felch quarry skull alongside those of other sauropods:
By re-ordering the top row, we can see what a neat intermediate it is between the skulls of Camarasaurus (left) and Giraffatitan (= “Brachiosaurus” of their usage):
I provisionally accepted USNM 5730 as belonging to Brachiosaurus in my re-evaluation of 2009, and included it in my reconstruction (Taylor 2009:fig. 7):
But as noted by Carpenter and Tidwell (1998:82), the lack of comparable parts between the Felch skull and the Brachiosaurus holotype (which remains the only definitive Brachiosaurus material) means that the assignment has to remain tentative.
What we really need is a more complete Brachiosaurus specimen: one with both a skull and good postcervical elements that let us refer it definitively to Brachiosaurus altithorax by comparison with the holotype. And heck, while we’re at it, let’s have a specimen with a good neck, too!
The real question remains: how did Marsh, using a brachiosaur skull as his basis, come up with this?
And stranger still, how someone at the Yale Peabody Museum — we don’t know who — used it, or more likely Marsh’s reconstruction, as a basis for this sculpture:
The Yale mount didn’t go up until 1931 — the last of the Big Four Apatosaurus mounts after the AMNH, Carnegie and Field Museum, which is surprising as it was the first of those specimens to be found. So by the time the skull was sculpted, sauropod skulls were actually reasonably well known. It’s not clear quite how anyone working from a decent reconstruction of, say, a Camarasaurus skull — the one in Osborn and Mook (1921:figure 30), say — could come up with this monster.
The last thing to say is this: it does credit to the YPM that they display this historically important sculpture rather than hiding it away and pretending it never happened. For me, part of the fascination of palaeontology is seeing not just how organisms evolved through prehistory but how ideas evolved through history. It’s great that we can still see important mistakes, alongside their corrections (i.e. the new and lovely skull on the YPM Apatosaurus mount.)
- Carpenter, Kenneth, and Virginia Tidwell. 1998. Preliminary description of a Brachiosaurus skull from Felch Quarry 1, Garden Park, Colorado. Modern Geology 23:69-84.
- Holland, William J. 1915. Heads and tails: a few notes relating to the structure of the sauropod dinosaurs. Annals of the Carnegie Museum 9:273-278.
- Janensch, Werner. 1914. Ubersicht uber der Wirbeltierfauna der Tendaguru-Schichten nebst einer kurzen Charakterisierung der neu aufgefuhrten Arten von Sauropoden. Archiv fur Biontologie, Berlin III, 1(1):81-110.
- Marsh, O. C. 1891. Restoration of Triceratops (with plates XV and XVI). American Journal of Science, 3rd series 41(244):339-342.
- McIntosh, John S., and David, S. Berman. 1975. Description of the palate and lower jaw of the sauropod dinosaur Diplodocus (Reptilia: Saurischia) with remarks on the nature of the skull of Apatosaurus. Journal of Paleontology 49(1):187-199.
- Osborn, Henry Fairfield, and Charles C. Mook. 1921. Camarasaurus, Amphicoelias and other sauropods of Cope. Memoirs of the American Museum of Natural History, n.s. 3:247-387, and plates LX-LXXXV.
- Riggs, Elmer S. 1903. Brachiosaurus altithorax, the largest known dinosaur. American Journal of Science 15(4):299-306.
- Taylor, Michael P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806.
October 15, 2014
October 5, 2014
Remember I picked up those three sheep skulls (and some other bones, including a complete neck) from a shallow pit in a field near where we live? Here is first of the skulls, cleaned up and photographed in orthogonal views.
It’s interesting to compare it to the pig skull from way back:
Sheep and pigs are both perfectly well-behaved artiodactyls, but their skulls are dramatically different. The pig is extraordinarily more robust, and has absolutely massive jaw-muscle fossae.
The sheep would have been difficult to prepare by the usual simmer-and-slice method — too easy to damage, especially inside the nasal cavity, where the respiratory turbinates are very fragile. The pig is a much easier proposition. I was able to clean out its nasal cavity just by running water through it at fairly high pressure, without doing any damage.
For anyone who wants to get into skull preparation, I definitely recommend starting with a pig.
September 30, 2014
Just a quick photo-post today. A couple of months ago, walking around the fields near our house, I found a broad shallow pit with a lot of a sheep skeletal elements in it. I took my youngest son out on an expedition, and we rescued the good material. I’ve cleaned up the first two (of three) skulls. Here is the smaller of the two — which is also more complete, and the big one has lost its nasals.
Click through for glorious high-resolution (4000 x 3000, and not a pixel wasted).
I took a nice set of orthogonal-view photos of this skull. When I have time, I will clean them up and composite them as I did with my pig-skull, which I’m sure you all remember:
(Well … I call it my pig skull, but it’s not mine any longer. I donated it as the prize for winning the TetZooCon quiz, and it is now the proud possession of Kelvin Britton. But I have another one, so that’s all right.)
Horrible sauropod skulls of the Yale Peabody Museum, part 2: Brontosaurus; and no, I do not mean Apatosaurus
April 15, 2014
How can it be?
All credit to the Yale Peabody Museum for having the courage to display this historically important object in their public gallery instead of hiding it in a basement. It’s the skull from the original mount of the Brontosaurus (= Apatosaurus) excelsus holotype YPM 1980.
Needless to say, it bears no resemblance at all to the actual skull of Apatosaurus, and the one they now have on the mount is much, much better:
But how did the YPM people ever arrive at this double-plus-ugly skull above? We see a similar skull in Marsh’s (1891) second attempt at restoring the skeleton of Brontosaurus:
But even this is not as ugly and Just Plain Wrong as the physical model they made. (Marsh’s first restoration of the Brontosaurus skeleton, in 1893, had a much less clear skull.)
So how did the YPM come to make such a monstrosity? What was it based on? Tune in next time for the surprising details!
Bizarrely, we’ve never really featured the YPM 1980 mount here on SV-POW! — we’ve often shown individual bones, but the mounted skeleton appears only in the background of the much less impressive Morosaurus (= Camarasaurus) lentus mount. We’ll fix that real soon.
March 24, 2014
Here’s a working version of that link.
- Falkingham (2012) on photogrammetry for free
- Mallison photogrammetry tutorial 1
- Mallison photogrammetry tutorial 2
- Mallison photogrammetry tutorial 3
- Mallison photogrammetry tutorial 4
- Powell, Jaime E. 2003. Revision of South American Titanosaurid dinosaurs: palaeobiological, palaeobiogeographical and phylogenetic aspects. Records of the Queen Victoria Museum 111: 1-94.