March 26, 2013
Another raw photo from the road.
The Morrison fossils from the Oklahoma panhandle were dug up and prepped out by WPA workers in the 1930s, and their preparation toolkit consisted of hammers, chisels, pen-knives, and sandpaper. (Feel free to take a minute if you need to get your nausea under control.) And whereas most Morrison fossils are much darker than the surrounding matrix, in the Oklahoma panhandle the bone and matrix are about the same color. Sometimes the prep guys didn’t know they’d gone too deep until they sanded into the trabecular bone. Or in this case, into the air spaces in the condyle of this anterior dorsal of Apatosaurus.
Still, we have lots of anterior dorsals of Apatosaurus, and very few we can see inside, and they’re too darned big to scan, so this gives us useful information that a more perfect specimen would not. So I salute you, underemployed dude from eighty-odd years ago. Thanks for showing me something cool.
March 24, 2013
Here’s an update from the road–get ready for some crappy raw images, because that’s all I have the time or energy to post (with one exception).
Here’s OMNH 1331. It’s just the slightly convex articular end off a big vertebra, collected near Kenton, Oklahoma, in 1930s by one of J. Willis Stovall’s field crews. I measured the preserved width at 45 cm using a tape measure, and at 44.5 in GIMP using the scale bar in the photo, which is up on a piece of styrofoam so it’s about the same distance from the camera as the rim of the vertebra (i.e, about 8 feet–as high as I could get and still shoot straight down). So whether your distrust runs to tape measures or scale bars in photos, I am prepared to argue that this sucker is roughly 45 cm wide.
There’s admittedly not a ton of morphology here, but the size and the fact that the other side is hollow and has a midline bony septum show that it is a pneumatic vertebra from a sauropod, and given that the quarry it’s from was chock-full of Apatosaurus, and liberally salted with gigantic Apatosaurus, I feel pretty good about calling it Apatosaurus.
To figure out how wide the articular face was when it was intact, I duplicated the image and reversed it left-to-right in GIMP, which yields an intact max width of about 49 cm. That is friggin’ immense.
If we make the maximally conservative assumption that this is the largest centrum in the whole skeleton of a big Apatosaurus, then it has to be part of a dorsal vertebra. Here are the max diameters of the largest dorsal centra in some big mounted apatosaurs, taken from Gilmore (1936). The number in parentheses is how many percent bigger OMNH 1331 is.
- A. louisae CM 3018 – 36.5 cm (34%)
- A. parvus UWGM 15556 – 36.5 cm (34%)
- A. sp. FMNH P25112 – 41 cm (20%)
However, this might not be part of a dorsal vertebra. For one thing, it’s pretty convex, and Apatosaurus dorsals sometimes have a little bump but they’re pretty close to amphiplatyan, at least in the posterior half of the series. For another, I think that smooth lower margin on the right in the photo above is part of the rim of a big pneumatic foramen, but it’s waaay up high and pretty medial on the centrum, opening more dorsally than laterally, which I have seen a lot in anterior caudal vertebrae. Finally, Jack McIntosh went through the OMNH collections years ago and his identifications formed the basis for a lot of the catalogue IDs, and this thing is catalogued as the condyle off the back end of a proximal caudal.
Here are the max diameters of the largest caudal centra in those same mounted apatosaurs, again taken from Gilmore (1936). Once again, the number in parentheses is how many percent bigger OMNH 1331 is.
- A. louisae CM 3018 – 30 cm (63%)
- A. parvus UWGM 15556 – 32.5 cm (51%)
- A. sp. FMNH P25112 – 39 cm (26%)
(Aside: check out the skinny rear end on A. louisae. ‘Sup with that?)
So whatever vert it’s part of, OMNH 1331 is damn big bone from a damn big Apatosaurus. There are lots of other big Apatosaurus vertebrae in the OMNH collections, like OMNH 1670, but OMNH 1331 is the largest centrum that I know of in this museum. Which is why you’re getting a post about most of one end of a centrum in the wee hours of the morning–it’s most of one end of an awesome centrum. And it pains me when people do comparison figures of big sauropod vertebrae, or lists of the “Top 10 Largest Sauropods”, and put in stuff like Argentinosaurus and Puertasaurus and Supersaurus, but leave out Apatosaurus. It was legitimately huge, and it’s time the world realized that.
For more on the giant Oklahoma Apatosaurus, see:
Gilmore, C.W. 1936. Osteology of Apatosaurus with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175-300.
February 4, 2013
There’s a lot more Sauroposeidon material these days than there used to be, thanks to the referral by D’Emic and Foreman (2012) of Paluxysaurus and Ostrom’s Cloverly material and the new Cloverly material to my favorite sauropod genus. I’ve seen almost all of this material firsthand, but obviously the specimen I’m most familiar with is the holotype, OMNH 53062. It was the primary thing occupying my mind from the summer of 1996 through the spring of 2000, and it has remained a frequent object of wonder ever since.
The specimen was found lying on its right side in the field, so that side is in better shape, by virtue of having been more deeply buried and thus protected from the ravages of freezing and thawing and other erosional processes. When the jackets were taken out of the ground and prepared, the not-so-well-preserved left sides were prepped first. Then permanent support jackets were made on the left sides, the vertebrae were flipped onto their left sides, the field jackets were removed from their right sides, and the vertebrae were prepped on the right. They’ve been lying in their support jackets, left side down and right side up, ever since. (For more on the taphonomy and recovery of the specimen, see this post and Wedel and Cifelli 2005 [free PDF linked below].)
Now, if I had known what I was doing, I would have photographed the crap out of the left sides before the verts were flipped. But it was my first project and I was learning on the job, and that didn’t occur to me until later.
It also didn’t occur to me that, once flipped, the left sides would be effectively out of reach forever. But the vertebrae are extremely fragile. The bigger verts have cracks running through them, and the jackets flexed noticeably when we took them for CT scanning. I am worried that if we tried to flip the bigger verts today, they might just crumble. Even the surface bone is fragile. I remember once trying to get some dust off one of the verts with a vacuum cleaner hose, and watching in horror as some of the millimeter-thin external bone just flaked off and flew away. That was in the late 1990s, when the verts were still stored in the dusty, drafty WWII-era buildings that had housed the museum collections for ages. Now they’re in what I still think of as the “new” building, which opened in 2000, in a really nice modern collection room with climate and dust control, and I’ve never seen them with any noticeable dust.
Anyway, the left sides are now obscured by their supporting jackets and will remain that way for the foreseeable future. And I don’t have a complete set of photos of the left sides of the verts. But I do have one, of the back half of ?C7 and all of ?C8, and a scan of it appears at the top of this post. It’s a scan of a physical photograph because it was taken in late 1996 or early 1997–no-one I knew had a digital camera, and if you wanted a digital version of a photograph, you shot it on a film camera, had a big print made, and scanned that on a flatbed scanner.
Here’s another version with the vertebrae outlined:
When I and everyone else thought that Sauroposeidon was a brachiosaur, I was pretty sure that these were C7 and C8, out of a total of 13 cervicals, just like Giraffatitan. And it still might be so–a future analysis might find that the newly-expanded Sauroposeidon is a brachiosaurid after all, and even if not, Gomani (2005) posited a primitive cervical count of 13 for titanosaurs. If that’s true, then possibly 13 cervicals are primitive for all titanosauriforms, and the increases beyond that–to 17 in Euhelopus and 14-17 in more derived titanosaurs like Futalognkosaurus and Rapetosaurus–were deviations from that primitive pattern.
If Sauroposeidon was a basal somphospondyl, as posited by D’Emic and Foreman (2012) and as found in the phylogenetic analysis of D’Emic (2012), then maybe it was more like Euhelopus than Giraffatitan, and maybe it had more than 13 cervicals. (Note that D’Emic  found Sauroposeidon to be a basal somphospondyl but outside the Euhelopodidae, so even in his analysis, Euhelopus could have gotten its extra cervicals independently of Sauroposeidon.) That’s an interesting prospect, since the 11.5-meter neck estimate for Sauroposeidon I made back in 2000 was based on the conservative assumption of 13 cervicals. If Sauroposeidon had more cervicals, they were probably mid-cervicals (nobody adds more dinky C3s, or stubby cervico-dorsals*–that would be silly), and therefore between 1 and 1.25 meters long. So if the individual represented by OMNH 53062 had 15 cervicals, as Mike hypothetically illustrated in this post, its neck might was probably more like 14 meters long, and if it had 17 cervicals, like Euhelopus and Rapetosaurus, its neck might have topped 16 meters–as long or longer than that of Supersaurus.
Now, I’m not saying that Sauroposeidon had a 16-meter neck. The conservative estimate is still 13 cervicals adding up to 11.5 meters. But the possibility of a longer neck is tantalizing, and can’t be ruled out based on current evidence. As usual, we need more fossils.
Happily, now that Sauroposeidon is known from Oklahoma, Texas, and Wyoming, and is one of the best-represented EKNApods instead of one of the scrappiest, the chances that we’ll find more of it–and recognize it–are looking good. I will keep my fingers firmly crossed–as they have been for the last 17 years.
* Radical pedantry note: of course we have very good evidence of sauropods getting more cervical vertebrae by recruiting dorsals into the cervical series. So, for example, 13 cervicals and 12 dorsals are supposed to be primitive for neosauropods, but diplodocids have 15 and 10, respectively–the obvious inference being that the first two dorsals got cervicalized. So in this narrow meristic sense, sauropods definitely did add cervicodorsals. But my point above is about the morphology of the verts themselves–once diplodocids had those two extra cervicals at the end, the former cervicodorsals were free to become more “cervicalized” in form. So effectively–in terms of the shapes of their necks–diplodocids added mid-cervicals.
- D’Emic, M.D. 2012. The early evolution of titanosauriform sauropod dinosaurs. Zoological Journal of the Linnean Society 166: 624–671.
- D’Emic, M.D., and B.Z. Foreman. 2012. The beginning of the sauropod dinosaur hiatus in North America: insights from the Lower Cretaceous Cloverly Formation of Wyoming. Journal of Vertebrate Paleontology 32(4): 883-902.
- Gomani, Elizabeth M. 2005. Sauropod dinosaurs from the Early Cretaceous of Malawi, Africa. Palaeontologia Electronica 8(1):27A (37 pp.)
- Wedel, M.J., and Cifelli, R.L. 2005. Sauroposeidon: Oklahoma’s native giant. Oklahoma Geology Notes 65 (2):40-57.
January 16, 2013
This photograph is of what I consider the closest thing to the Platonic Ideal sauropod vertebra: it’s the eighth cervical of our old friend the Giraffatitan brancai paralectotype MB.R.2181. (previously known as “Brachiosaurus” brancai HM S II — yes, it’s changed genus and specimen number, both recently, but independently.)
And if you look very carefully, down at the bottom, you can see the same vertebra, C8, of the prosauropod Plateosaurus. Pfft.
This photo was taken down in the basement of the Museum für Naturkunde Berlin, on the same 2008 trip where Matt took the “Mike in Love” photo from two days ago. For anyone who didn’t recognise the specific vertebra I was in love with in that picture, shame on you! It is of course our old friend the ?8th dorsal vertebra of the same specimen, which we’ve discussed in detail here on account of its unique spinoparapophyseal laminae, its unexpectedly missing infradiapophyseal lamina and its bizarre perforate anterior centroparapophyseal laminae.
January 14, 2013
Matt took this photo in the basement of the Museum für Naturkunde Berlin, back in 2008 when we were there as part of the field-trip associated with the Bonn sauropod conference.
Hopefully all you long-time SV-POW! readers will recognise the specific vertebra that I’m in love with.
June 27, 2012
From the collections of the American Museum of Natural History, I give you the sacrum and fused ilia of “Apatosaurus” minimus AMNH 675, as correctly identified by Steve P in a comment to the previous post:
As Steve P rightly pointed out, AMNH 675 was designated as Brontosaurus sp. by Osborn (1904), and made the type of Apatosaurus minimus by Mook (1917).
It’s been known for some time that whatever this is, it’s not Apatosaurus — see for example McIntosh (1990a:398), McIntosh (1990b:59) and Upchurch et al. (2004:298). But what actually is it? Well, at the moment, no-one knows. Matt and I now have a manuscript in prep that we hope will somewhat elucidate this question. More to come on this specimen, most likely.
McIntosh, John S. 1990a. Sauropoda. In The Dinosauria, pp. 345–401. Berkeley and Los Angeles: University of California Press.
McIntosh, John S. 1990b. Species Determination in Sauropod Dinosaurs with Tentative Suggestions for the Their Classification. In Dinosaur Systematics: Approaches and Perspectives, pp. 53–69. Cambridge: Cambridge University Press.
Mook, Charles C. 1917. Criteria for the determination of species in the Sauropoda, with description of a new species of Apatosaurus. Bulletin of the American Museum of Natural History 38:355-360.
Osborn, Henry F. 1904. Manus, sacrum, and caudals of Sauropoda. Bulletin of the American Museum of Natural History 20:181-190.
June 25, 2012
A couple of posts back, when Matt was talking about turtle laminae, he included a photo of me in front of the skeleton of the giant turtle Archelon. Also in that photo is the tripod I was using — if you want to call it that — a tripod of altogether startling inadequacy. Here it is again, this time in the collections of the AMNH:
(Bonus SV-POW! points for anyone who can tell me what taxon or specimen I am working on. Sorry, Heinrich, you’re disqualified, since you already know.)
Why did we use such a poor tripod? Matt was planning to bring a proper one, but at the last minute decided to downsize his luggage by taking one small enough to fit into a smaller bag — in fact, it’s the tripod that came free with a telescope he recently bought. Not a good move: it was too short for many of the shots we wanted to take, too flimsy to properly stabilise the camera in many situations, and didn’t have enough degrees of freedom to let us get every shot we wanted from the best position.
Still, it was better than nothing, and we did contrive to get all the specimen photos we needed.
At the end of the week, when we finished up in collections and went to catch our taxi to the airport, Matt left the tripod behind. I emailed our AMNH host Carl Mehling to explain:
Matt deliberately left behind his tripod — it’s on the desk where we had the pelvic elements. He has much better tripods at home, and regrets the false economy of bringing that lighter and less stable one. But we figured it would be better than nothing for the use of anyone who turns up in collections with no tripod at all, so please feel free to make it available to visitors. Matt asks only that it be known as “The Mathew J. Wedel Memorial Tripod”.
Thanks so much for the tripod – I KNOW it will come in handy!
Ah, sorry about this but my client insists that it must be known by its full title The Mathew J. Wedel Memorial Tripod at all times. If necessary, you may abbreviate it to TMJWMT on second and subsequent mentions.
I can engrave it in the Lab and apply a B72/India Ink/B72 sandwich acronym/monogram on it. I will also construct an archival museum mount for it and put a security chip in its brain.
That’s when Matt himself weighed in:
Oh, and be sure that when the tripod is not in use it is stored in an airtight positive pressure chamber full of an inert gas. It should also be polished twice daily with the down of a hatchling bald eagle (fresh down each time, naturally). Finally, the tripod itself should be listed as an author on any publications that include photos taken with it. Please send a runner to my office in California to confirm that these instructions will be carried out to the letter.
The runner hasn’t arrived yet (to my knowledge) but I think we can take it as read that Carl will comply with these very reasonable conditions.
So, folks! If ever you’re working in the AMNH big-bone room, and you find you’ve forgotten your tripod … you might just be lucky enough to be allowed use of the Mathew J. Wedel Memorial Tripod!