April 8, 2013
Last night London and I spent the night in the Natural History Museum of Los Angeles County (LACM), as part of the Camp Dino overnight adventure. So we got lots of time to roam the exhibit halls when they were–very atypically–almost empty. Above are the museum’s mounted Triceratops–or one of them, anyway–and mounted cast of the Mamenchisaurus hochuanensis holotype, presented in glorious not-stygian-darkness (if you went through the old dino hall, pre-renovation, you know what I mean).
We got there early and had time to roam around the museum grounds in Exposition Park. The darned-near-life-size bronze dinos out front are a minor LA landmark.
The rose garden was already closed, but we walked by anyway, and caught this rainbow in the big fountain.
After we checked in we had a little time to roam the museum on our own. I’ve been meaning to blog about how much I love the renovated dinosaur halls. The bases are cleverly designed to prohibit people touching the skeletons without putting railings or more than minimal glass in the way, and you can walk all the way around the mounted skeletons and look down on them from the mezzanine–none of that People’s Gloriously Efficient Cattle Chute of Compulsory Dinosaur Appreciation business. Signage is discreet and informative, and so are the handful of interactive gizmos. London and I spent a few minutes using a big touch-screen with a slider that controlled continental drift from the Triassic to the present–a nice example of using technology to add value to an exhibit without taking away from the real stuff that’s on display. There are even a few places to sit and just take it all in. That’s pretty much everything I want in a dinosaur hall.
Also, check out the jumbotron on the left in the above photo. It was running a (blessedly) narration-free video on how fossils are found, collected, prepared, mounted, and studied, on about a five-minute loop. Lots of pretty pictures. Including this next one.
There are a couple of levels of perspective distortion going on here, both in the original photo and in my photo of that photo projected on the jumbotron.
Still, I feel confident positing that that is one goldurned big ilium. I’m not going to claim it’s the biggest bone I’ve ever seen–that rarely ends well–but sheesh, it’s gotta be pretty freakin’ big. And apparently a brachiosaurid, or close to it. Never mind, it’s almost certainly an upside-down Triceratops skull. Thanks to Adam Yates for the catch. I will now diminish, and go into the West.
Triceratops, Styracosaurus, and Einiosaurus–collect the whole set!
Of course, the centerpiece of the second dinosaur hall–and how great is it that there are two!?–is the T. rex trio: baby, juvenile (out of frame to the right), and subadult. Yes, subadult: the “big” one is not as big as the really big rexes, and from the second floor you can see unfused neural arches in some of the caudal vertebrae (many thanks to Ashley Fragomeni for pointing those out to me on a previous visit).
Awwwww! C’mere, little fella!
Still, this ain’t Vulgar Overstudied Theropod Picture of the Week. Here are some sweet pneumatic diplodocid caudals in the big wall o’ fossils (visible behind Mamenchisaurus in the overhead photo above). The greenish color is legit–in the Dino Lab on the second floor, they’re prepping a bunch of sauropod elements that look like they were carved out of jade.
Sudden violent topic shift, the reason for which will be become clear shortly: London and I have been sculpting weapons of mass predation in our spare time. In some of the photos you may be able to see his necklace, which has a shark tooth he sculpted himself. Here are a couple of allosaur claws I made–more on those another time.
The point is, enthusiasm for DIY fossils is running very high at Casa Wedel, so London’s favorite activity of the evening was molding and casting. Everyone got to make a press mold using a small theropod tooth, a trilobite, or a Velociraptor claw. Most of the kids I overheard opted for the tooth, but London went straight for the claw.
Ready for plaster! Everyone got to pick up their cast at breakfast this morning, with instructions to let them cure until this evening. All went well, so I’ll spare you a photo of this same shape in reverse.
We were split into three tribes of maybe 30-40 people each, and each tribe bedded down in a different hall. The T. rex and Raptor tribes got the North American wildlife halls, but our Triceratops tribe got the African wildlife hall, which as a place to sleep is about 900 times cooler. Someone had already claimed the lions when we got there, so London picked hyenas as our totem animals.
Lights out was at 10:30 PM, and the lights came back on at 7:00 this morning. Breakfast was out from 7:15 to 8:00, and then we had the museum to ourselves until the public came in at 9:30. So I got a lot of uncluttered photos of stuff I don’t usually get to photograph, like this ammonite. Everyone should have one of these.
London’s favorite dino in the museum is Carnotaurus. It’s sufficiently weird that I can respect that choice.
Not that there’s anything wrong with the old standards, especially when they’re presented as cleanly and innovatively as they are here.
Finally, the LACM has a no tripod policy, and if they see you trying to carry one in they will make you take it back to your car. At least during normal business hours. But no one searched my backpack when we went in last night, and I put that sucker to some good use. Including getting my first non-bigfoot picture of the cast Argentinosaurus dorsal. It was a little deja-vu-ey after just spending so much time with the giant Oklahoma Apatosaurus–elements of the two animals really are very comparable in size.
If you’re in the LA area and interested in spending a night at the museum–or at the tar pits!–check out the “Overnight Adventures” page on the museum’s website. Cost is $50 per person for members or $55 for non-members, and worth every penny IMHO. It’s one of those things I wish we’d done years ago.
My spouse, Vicki, the other Dr. Wedel, is a physical and forensic anthropologist. And she’s one of a very small number of scientists who have (a) learned something new about the human body, and (b) used it to help identify dead people. And since that process involves the sciences of hard-tissue histology and skeletochronology–not to mention lots of dead folks–I reckon it might be of interest here. Hence this post.
This started about a decade ago, when Vicki was working on her PhD under Alison Galloway at UC Santa Cruz. Vicki worked with Alison on a ton of forensic cases, including some you probably heard of–they analyzed the remains of Laci Peterson and her unborn baby, Connor, for Scott Peterson’s murder trial. I had the unusual privilege of assisting a couple of times, on other cases, once to take some pictures in the lab while Vicki fished the skeleton out of the bag of skin that was all that was left of the body, and once to crawl around on my hands and knees picking human finger bones out of a muddy slough near Santa Cruz. All in all, I’m happy that my usual victims have been dead a lot longer.
Incidentally, the only show with forensic content that Vicki will watch voluntarily is Dexter. She cannot stand CSI, NCIS, or the other “behind the scenes” forensic investigation shows. We’ve tried watching them, but the inaccuracies drive her crazy (paleo people: imagine getting the Clockwork Orange therapy and being forced to watch Clash of the Dinosaurs). Real cases are solved by teams of specialists, not two omnicompetent protagonists; it takes weeks or months, not half an hour; and if the forensics people carry guns, it’s because they know waaaay too much about how some very bad, very organized people dispose of bodies (the short answer is, not thoroughly enough*).
* Once a guy who was threatening to testify against a certain criminal organization was shot in the head, his body burned, and his burnt remains scattered along the side of the road. Vicki and Alison picked the bone shards out of the roadside gravel, identified some of them as bits of skull, and found bevelling diagnostic of ballistics trauma on some of those. The way the bone had shattered showed that the gunshot had been inflicted perimortem–around the time of death–and before the body was burned. Bottom line, whatever plan you have to get rid of the body, it is probably not going to be enough to keep someone like Vicki from figuring out how you did it. That much, the TV shows do get right.
Not only is hard to really, truly get rid of a human body, it’s also hard to tell exactly when a person died, especially if all you have is a body in the woods. Insects are good–there’s a whole field of forensic entomology, whose practitioners age cadavers based on what insects are present and what stages of their life cycles they’re in. But what if all that is left is a pile of bones in the woods (which happens more often that you might think, and sometimes for completely innocuous reasons)? I’m preaching to the choir here, but bones can survive for a long time, so general wear-and-tear doesn’t tell you much. Rapetosaurus looks like it died last year.
There’s another side to this, which is figuring out how old someone was at the time of death based on their skeleton. Tooth eruption is good, and fusion of the epiphyseal growth plates, but both of those processes are basically done by the time people are in their mid-20s (teeth) to mid-30s (epiphyseal fusion). After that, there are methods based on the morphology of the auricular surface of the ilium and the public symphyses, but these only narrow things down to intervals of 5 to 15 years, and that’s a lot of missing persons reports to sift through. And none of the regular skeletal methods work past the age of 55 or 60. After that, no matter how healthy you are, the primary skeletal changes are attritional (i.e., you’re wearing out), and that process varies so much among individuals and populations that there are basically no predictive guidelines.
All of this was on Vicki’s mind when she was a grad student, so she was alert to anything that might help forensic anthropologists narrow down the possibilities for identifying dead folks. She was teaching in an osteology course and one of her students, Josh Peabody, brought up dental cementum increment analysis (DCIA), which is used in zooarcheology to determine the age and season at death of animal remains found at archaeological sites. Josh wanted to know if the method worked on humans.
At the time–2004–DCIA was being tested for age at death in some historical human populations from archaeological sites, but no-one had tried using it for season at death. So Vicki and Josh set out to see if it would work.
Our teeth, like those of other mammals, are held in their sockets by periodontal ligaments. The periodontal ligament of each tooth attaches via Sharpey’s fibers to the dental cementum on the tooth root(s). Cementum is laid down in annual bands, so you can count the number of bands on a tooth, add the normal age at which that tooth erupts, and get a pretty tight estimate of when the animal died. So much for age at death, which was already being done on humans in a limited way in the early 2000s, albeit in archaeological rather than forensic contexts.
But wait, there’s more. Actually two bands of cementum are laid down every year–a dark band in the winter (roughly October to March) and a light band in the summer (roughly April to September). ‘Dark’ and ‘light’ describe the appearance of the bands under polarized light microscopy. In the summer months, the collagen fibrils that make up the cementum are aligned parallel to the tooth root, so more light comes through. In the winter, the collagen is aligned perpendicular to the root, so less light is transmitted, and the winter bands appear darker by comparison. So not only does the number of pairs of light-and-dark bands tell you the number of years since the tooth erupted, the color of the outermost band tells you in which six-month period the individual died, and the thickness of the outermost band might help you narrow that down even further.
At least, that’s how it works in other mammals. Would it hold up in humans? After all, we’re pretty good at adjusting our environments to suit us, rather than vice versa. If the winter-summer banding pattern was present in humans, it would be a huge boon to forensic science. Even people in their 40s and beyond with no very reliable skeletal indicators of age could be aged to within a year or two, and their season at death narrowed down to a 2-3 month window.
To find out, Vicki and Josh had a dentist in Santa Cruz collect 112 teeth pulled from patients over the course of a year (with full IRB approval and informed consent from the dental patients). For their purposes, a tooth pulled from a live person is just as good as one from a cadaver or skeleton–extraction kills the tooth as surely as death of the body. Better, even, in that it was easier to quickly get lots of teeth with very precise extraction data.
Vicki and Josh cut a few teeth together and they found dark and light bands right away. They presented those preliminary results at the American Academy of Forensic Sciences meeting in 2005. After that, Josh got busy with his own research, but Vicki pressed on (while finishing a dissertation on different project, and being a first-time mom).
If this was a movie, this is the part where there would be a montage of inspirational music to get us quickly past a lot of hard, boring work. Each of the 112 teeth had to be embedded in plastic, a section through the root cut out with a saw, that section mounted on a slide and ground down until it was translucent (this process will be familiar to bone histologists of all stripes, paleo or neo). Then Vicki had to go all the way around the perimeter of the each root to find the place where the cementum bands showed the most clearly, and count them. This part is trickier than it sounds, unless you’ve done some histo and know just how butt-ugly some sections can be under the scope.
The results? In the words of the Bloodhound Gang, which Vicki quotes in her DCIA talks, “You and me baby ain’t nothin’ but mammals”. Here’s the payoff graph:
The one out-of-place measurement was probably caused by the dark band not being thick enough to register clearly on the image.
Now that she knew that DCIA could be used to determine season at death in humans, Vicki started applying it in her forensic cases, of which there have been many. The vast majority of the work of forensic anthropologists is invisible to the public: after analyzing a set of remains, a forensic anthropologist writes a case report for whatever law enforcement office (or, much less frequently, law firm or other entity) brought them in, and that’s that. The case reports are almost always confidential, but they have to be written to exacting standards since they may be used as evidence in court. So forensic anthropologists spend a lot of time toiling over papers that hardly anyone gets to read.
However, sometimes a case is written up for journal publication–if it’s sufficiently novel or unusual, and if permission can be secured from all of the relevant parties. In 2008, Vicki was approached by the Merced County sheriff’s office to help try to identify the remains of a young woman who had been murdered in 1971. That’s the 37-year-old cold case mentioned in the title of this post, and rather than tell you about it, I’ll point you to Vicki’s case report (Wedel et al. 2013), published last month in the Journal of Forensic Identification and freely available here.
I wasn’t sure whether to post about this or not–as cool as they are, murder cases are not our normal stock in trade on this blog. What decided me was talking with Andy Farke. He read Vicki’s paper as soon as it came out, and he said that he really enjoyed getting to see how forensic anthropologists work in the real world. I sometimes take for granted that, since I am married to a forensic anthropologist, I get to see how this works all the time. But that’s a pretty rare experience–if paleontology is a small field, forensic anthropology is positively tiny. So if you want to see an example of the real science that CSI and the like are based on, here’s your window.
What’s next? Vicki has several validation studies on DCIA in progress, for which she and her collaborators have collected a much larger sample size–over 1000 teeth–to try to answer questions like: what tooth is best to use for DCIA? Should the histological sections be made longitudinally or transversely through the tooth root? Does cementum banding vary with latitude? And since banding patterns are reversed in the Southern Hemisphere, following the flip-flopped season, what happens at the equator? Watch this space, and keep an eye out for Vicki’s future publications–including a book due out next year–at her website, Bodies, Bugs, and Bones.
- Wedel, V.L. 2007b. Determination of season at death using dental cementum increment analysis. Journal of Forensic Sciences 52(6): 1334-1337.
- Wedel, V.L., G. Found, and G.L. Nusse. 2013. A 37 year-old cold case identification using novel and collaborative methods. Journal of Forensic Identification 63(1): 5-21.
February 20, 2013
Hi folks, Matt here. This is a ridiculously busy week for me, for reasons that will become clear by the end of the post, so I’m bundling some news items.
First, my dissertation–which has been freely available online since 2007 anyway–is now on arXiv (link). Just in case the meteor takes out both me and WordPress but leaves arXiv unscathed, or possibly some outlet will let you cite arXived works but not “unpublished” ones. It was fast, easy, and free, and you should do the same with your (completed!) thesis or dissertation. Matt Cobley just posted his MS thesis, “The flexibility and musculature of the ostrich neck: Implications for the feeding ecology and reconstruction of the Sauropoda (Dinosauria:Saurischia)“, which is very timely and important work, and which you should go read right now. Mike and I cited both Matt’s thesis and my own diss. in our recent PeerJ paper, and the bibliographic entry for my diss. includes a link to the copy posted on my CV page, but arXiv links would have been simpler, faster, and probably more stable over the long run. Oddly enough, in the first proof the citation of my dissertation was removed, presumably by an automated process, since (a) PeerJ does allow citations of theses and dissertations–we checked, and (b) we suspected that already, because our citation of Matt Cobley’s work survived unscathed. Anyway, we just wrote back and asked them to add it back in, and they did–which has consistently been our experience as PeerJ members, and indeed as human beings: it’s often a pleasant surprise how much you can get just by asking nicely.
Speaking of PeerJ, the second batch of articles arrived today, 10 this time, including one on the evolution of whale teeth (see image at top). And, as I threatened to do last week, I used PeerJ in the classroom today, in talking with the MS students about how peer review works. Not only did it feel fantastic to be able to point the students to a whole bunch of published examples of peer review “in the wild”, but I got some good questions and comments after class. I don’t pretend to be nonpartisan about PeerJ. I think it’s the greatest thing since sliced bread. But frankly it didn’t take much selling. The interface is so intuitive and puts so much info at your fingertips that it feels very un-journal-like. What it feels like, in fact, is the first outlet (I almost said “journal”–how 2012 of me!) designed from the ground up to take full advantage of the web (feel free to quibble, PLOS fans, but I’m standing by that), and the students get that right away.
Finally, I’m giving a couple of talks here on campus later this week, and if you’re in the area and not already bored to tears by my yammering on about inflated dinosaurs, you should come by. First up, Thursday at 5:30 at WesternU’s Pumerantz Library is my family-friendly, “Flip-top heads, air-filled bones, and teenage pregnancy: how the largest dinosaurs got so big”. Then on Friday in Compatriots’ Hall in the Health Sciences Center (HSC–southwest corner of Palomares and 2nd St. in Pomona) is my more-technical-but-hopefully-not-forbiddingly-so college seminar talk, “Pneumatic bones and giant dinosaurs: an update on 5 more years of research”, or as I call it, “Thanks for giving me a job in 2008, here’s how I’ve been earning my keep”.
That’s all for now–gotta go polish those talks!
UPDATE a few hours later:
How to get to my talks, if you’re not familiar with the WU campus. Red arrows show you on what sides of these giant square buildings to find the entrances. For the library talk, walk through the front doors and BAM! you’re there. For Friday’s talk, go left around the staircase and into the nice conference room just past the atrium. Be warned, almost all the lots you can see in the satellite view require university permits during business hours, and street parking may be hard to scare up on Friday.
Big news yesterday. Identical bills were introduced into the US House of Representatives and Senate that, if passed, will make federally-funded research freely available within six months of publication. Here’s the exact wording, from the press release on Mike Doyle’s (D-PA) website:
The Fair Access to Science and Technology Research Act (FASTR) would require federal agencies with annual extramural research budgets of $100 million or more to provide the public with online access to research manuscripts stemming from funded research no later than six months after publication in a peer-reviewed journal.
As Peter Suber explains here and here, FASTR is a stronger version of FRPAA, the Federal Research Public Access Act, which has been introduced in Congress three times before (2006, 2009, and 2012) but never come up for a vote. However, momentum for open access is gathering, both on the supply side with progressive new outlets like eLife and PeerJ, and on the demand side of, well, citizens demanding access to the research they’ve already paid for, and legislators increasingly agreeing with them. So FASTR has a real shot at getting to a vote, and if voted on, could well pass. Which would be awesome, because we all need access.
I am especially happy that FASTR has bipartisan sponsorship in both houses of Congress. The sponsoring representatives in the House are Mike Doyle (D-PA), Kevin Yoder (R-KS), and Zoe Lofgren (D-CA). The identical Senate bill was introduced by John Cornyn (R-TX) and Ron Wyden (D-OR). So we’ve got Democrats from deeply blue states and Republicans from deeply red states, which is awesome and totally appropriate, because this issue really does cut across party lines. And, hell, last year Elsevier managed to hire bipartisan sponsorship for their toxic–in more ways than one–and rapidly-killed Research Works Act, so it’s nicely symmetrical that politicians from both sides of the aisle have come together to sponsor that bill’s near-opposite.
What can you do? If you live in the US, contact your legislators and tell them to support FASTR! It takes almost no time at all and it makes a big difference. This afternoon I called all five of the sponsoring legislators to thank them, and I called my representative and both California senators to encourage them to support the bill, and all told it took just a little over half an hour. If you skipped the thank yous and just got in touch with the legislators who represent you, it could be done in 15 minutes, and you’ve probably wasted more time than that today daydreaming about dinosaurs. Here’s what you’ll need.
Encourage your legislators:
Thank the bills’ sponsors:
- Senator John Cornyn (R-TX): (202) 224-2934
- Senator Ron Wyden (D-OR): (202) 224-5244
- Representative Mike Doyle (D-PA): (202) 225-2135
- Representative Zoe Lofgren (D-CA): (202) 225-3072
- Representative Kevin Yoder (R-KS): (202) 225-2865
This is big. This matters. Send an email, pick up the phone, make a difference.
I didn’t have any really motivational “contact your legislators!” artwork so the photos in this post are of papier mache dinosaurs–all stinkin’ theropods, I’m afraid–that I’m building with my son. More to come on that soon, but in the meantime, check this out and give it a whirl–after you contact your legislators!
February 6, 2013
Continuing the recent theme. We’re not giving this a “Things to Make and Do” header because the spirit of that category is to showcase anatomical preparations that average people could do in the comfort of their own homes and gardens (provided they can get hold of dead wallabies, bear skulls, etc.), and freezing and band-sawing a horse is probably outside that envelope for almost everyone (I hadn’t though of that when I posted the gator!).
In the spirit of MYDHHH:
This ain’t mine, it’s a teaching specimen from our vet school, which has a no-kill policy. All of the animal cadavers used in the anatomy labs are donated by the owners at the ends of the animals’ natural lives. So no animals were harmed in the making of this science.
But I wish it was mine. And as long as I’m dreaming, I’d like a pony. Anyone want to go halvesies?
January 22, 2013
Our friends Tim and Michelle Williams moved into a local house a few months ago. In the garage, they found a jam jar containing the bones of a squirrel and the remains of its rotting flesh, dated 1985: presumably a zoologist lived in that house 28 years ago, began preparing a specimen, and moved out before finishing.
Tim was inexplicably lacking in excitement over this discovery, and passed the jar to me. I cleaned the bones (holding my nose) and am now the proud owner of a plastic tub full of tiny, tiny bones. Among the most interesting are the mandibles, and here’s why. First, I’ll show you the right mandible in medial view, with its incisor sitting in its socket as it would have done in life:
The bones were clean enough that the teeth all came out of their sockets, so here is the same mandible in the same aspect to the same scale, but with the tooth removed:
I know! It’s ridiculous! You wouldn’t think it would ever fit inside the bone of the jaw! But it does — just. Here are the tooth and the jaw juxtaposed:
So there is it: the tooth literally could not be any bigger.
Rodents: they’re not quite as dull as you think.
November 1, 2012
One of our anatomy students this year, Tess MacFife, was inspired by the other Dr. Wedel’s skull lecture and produced this excellent anatomy-inspired jack-o-lantern:
Random passers-by probably thought this was some kind of bat/demon/Lovecraftian horror, but those in the know would recognize it as the human sphenoid bone in anterior view. Tess writes, “Full disclosure, I did print out a template and used toothpicks for the outline.” Here’s her template image, borrowed from here.
Any other anatomy- or paleontology-inspired Halloween geekery this year? Feel free to alert us in the comments. And well done, Tess!
June 17, 2012
Check this baby out:
I know, I know what you’re thinking. “Enough with the vulgar overexposed skull of this beast, Taylor”, you cry: “Show us its zygapophyses!”
But of course.
This is from the anterior part of the tail, in right lateral view: the vertebrae that you see here are the third to seventh of those that carry chevrons.
The hot news here is of course that sperm whales go to all the bother of developing zygapophyses, right up at the top of their neural arches, down in a region of the body where they don’t come close to articulating and are of no conceivable use.
Anyone know why? Care to hazard a guess?
November 21, 2011
- Part 1: intro
- Part 2: the head
- Part 3: the neck
- Part 5: posture
- Part 6: texture and color
- Part 7: verdict
A long-running theme here at SV-POW! is that the torsos of most sauropods were not just deep and slab-sided, they were unusually deep and slab-sided, more so than in most other tetrapods (see this and this, and for a more pessimistic take, this). This is something that is easy to get wrong; we are used to seeing round mammalian torsos and a lot of toy sauropods have nearly circular cross-sections. A lot of sculptors of collectible dinos do get the torso cross-section right, though, and the folks who made this Apatosaurus are no exception.
Next item: there’s an upward kink at the base of the tail, as there should be. Gilmore was the first to point this out, in his 1932 paper on the mounting of the Smithsonian Diplodocus (that’s plate 6 from that paper above; the skeleton on the bottom is the more correct one). This came up in the comment thread of the first post in this series, and since I haven’t had any deeper thoughts on the issue in the past week, I’m just going to copy and paste what I wrote then:
The upkink at the base of the tail is unavoidable; the sacrum is shaped like an inverted keystone and there’s no way to get the proximal caudals to do anything but angle upward without disarticulating them…. The reverse keystoning of sauropod sacra is weird. And it’s in every sauropod sacrum I can remember seeing with my own eyes, including Brachiosaurus altithorax. And yet the only authors I can think of off the top of my head who have discussed it seriously are Gilmore (1932), Greg Paul (2010, maybe a magazine article or two I haven’t seen), maybe Jim Jensen (1988), and IIRC Salgado et al. (1997). If there are more, please let me know–this is something I’m very curious about.
The back is gently arched, with the highest point about midway between the shoulder and hip joints. Where the highest point in the back falls depends on a host of factors, including the relative lengths of the forelimb and hindlimb bones, the amount of cartilage on the ends of those bones, the position and angle of the scapula on the ribcage, and the intrinsic curvature, if any, of the articulated series of dorsal vertebrae, which were themselves separated by an unknown amount of cartilage. Opinions are all over the map on most of these issues, particularly scapular orientation. As a scientist, I am agnostic on most of these points; I don’t think that they’re beyond being sorted out, but there’s a lot of work in progress right now and I haven’t seen evidence that would definitely convince me one way or another. So in lieu of saying that Apatosaurus must have had this scapular orientation and that dorsal curvature and so on, I’ll just note that the maquette has been a dominant feature in my office for a few weeks now and nothing about the body profile, shoulder position, or limb length has ever struck me as odd or worthy of comment. It looks like Apatosaurus to me. Moving on…
In the last post I talked about the visible bulges in the neck that allow one to count the cervical vertebrae. The maquette also has low bumps along the back that mark the neural spines of the dorsal vertebrae. This doesn’t strike me as unreasonable. Attachment scars for interspinous ligaments run all the way up to the tips of the neural spines in most sauropods, so the entire height of one neural spine was often webbed to the next by a continuous ligamentous sheet, as Janensch (1929: plate 4) drew for Dicraeosaurus in the illustration above (isp.L). I don’t think those ligaments would have prevented the bony tips of the vertebrae from being visible, necessarily, and the epaxial muscles should have been on either side of the interspinous ligaments and in the triangular spaces between the spine tips and the transverse processes.
What might have smoothed out the dorsal body profile are supraspinous ligaments (ssp.L in the plate above). These are present in crocs (Frey 1988: figs. 14, 16, 17) but apparently absent in most birds; at least, I haven’t seen any myself, and the Nomina Anatomica Avium does not mention any (Baumel et al. 1993: 156-157). So on phylogenetic grounds their presence in sauropods is equivocal. That said, the tips of the neural spines in most sauropods are fairly rugose. Does that mean that they were webbed one to the next by interspinous ligaments only, or that they were embedded in supraspinous ligaments as well? I don’t know the answer, and I don’t know if anyone else does, either. The whole issue of intervertebral ligaments in sauropods has received too little attention to date. In the absence of better data, I’ll just say that although I wouldn’t put any money on the proposition that the spines made externally visible bumps in life, neither does it offend me.
There is one fairly nit-picky point that I am honor-bound to mention. Because the dorsal neural spines make bumps, it is possible to count the dorsals, just like the cervicals last time. And this count doesn’t work out quite as well. Apatosaurus should have 10 dorsal vertebrae, but try as I might I can’t see more than 8 bumps along the back, and that’s generously assuming that c14′s spine is pretty well ahead of its rib. Is this pathologically anal to complain about? Quite possibly. On the other hand, by sculpting in those details the artists were basically begging geeks like me to come along and count vertebrae just because we could.
The tail is pretty cool. It is appropriately massive where it leaves the body, and has a visible bulge for the caudofemoralis muscle, which originated in the tail and inserted on the fourth trochanter of the femur. The caudofemoralis is the major femur retractor in lizards and crocs and in most non-avian dinosaurs, and rather than go on about it I’ll just point you to Heinrich Mallison’s awesome post about dinosaur butts. The tail of the maquette also has an awesome whiplash. I could say a ton more about the hypothesized uses of whiplash tails in diplodocids and other sauropods, but I don’t feel like climbing that hill just now. Suffice it to say that the maquette’s whiplash is pretty sweet, and avoids the “scale is too small so I just stuck in a piece of wire” mode of making whiplashes that I’ve seen in other, smaller diplodocid sculpts.
The tail has a row of little spines running down the dorsal midline, which have been de rigeur for life restorations of diplodocids and many other sauropods (ahem) since they were first reported by Czerkas (1993). AFAIK, such spines have only been found preserved in the tail region of diplodocids. That’s not to say that they weren’t present in the neck or the back of diplodocids, or in other sauropod taxa, just that the only good fossil traces of them to date have been from the tails of diplodocids, and maybe just one or two tails. So the presence of little spines in the tail of the maquette and not the back or the neck is perfectly–one might even say slavishly–consistent with the fossil evidence. I’ll discuss the flamboyancy or lack thereof in the maquette in another post, so I’ll say no more about this design choice for now.
The limbs are mostly good. The muscles under the skin look plausible, with one exception. As noted before in this series, Apatosaurus was a freakishly robust critter, and the limbs look appropriately sturdy and well-muscled, except where the thigh meets the hip. There is a visible bulge for the ilium, and the anterior margin of the thigh should converge with the most forward point on the ilium. That’s what the preacetabular blade of the ilium is for: to anchor thigh muscles (discussed here, and also nicely illustrated here). Unless the animal had some kind of wasting disease, there was no bone sticking out beyond the muscle, and so the anterior-most point of the ilium has to be the start of the anterior margin of the thigh.
On the positive side, there’s a little ridge running down from the anterior arm onto the forearm for the biceps tendon, which is a nice touch. The manus shows the short, solid arc of metacarpals typical for diplodocids, and an inward-curving thumb claw. The hind feet have the big laterally-curving claws on the first three digits that one expects.
In a way that is difficult to describe in words, the feet really look they are bearing a lot of weight, and this impression of solidity helps to ground the whole maquette. It doesn’t look like a sauropod-shaped balloon that just happens to be poling itself along with limbs that barely touch the ground–an impression that I have gotten occasionally from some other sculptures with overly skinny limbs and too-small feet. This critter looks big, heavy, and powerful, and those are exactly the adjectives one wants to come to mind when looking at Apatosaurus. (I do wonder if doing a Diplodocus in the same scale would be more difficult. How do you convey ‘multi-ton animal’ and ‘gracile’ at the same time?)
To sum up, in the trunk, tail, and limbs I find much to like and little to criticize. The only noteworthy problems are the insufficient dorsal count and the mismatch between the ilium and anterior thigh profile. On one hand these are puzzling goofs, given the overall attention to detail and the numerous points at which the sculpt is not just good but surprisingly good. On the other hand, I didn’t notice the dorsal thing until I bothered to count, and I didn’t notice the thigh thing until the other day when I was writing the first draft of this post, so both problems went unnoticed for weeks and are probably below the threshold of perception for the vast majority of people. The accuracy of the sculpt is so high that my approach to its problems has not been, “Where do I begin?” but rather, “What is keeping this thing from being perfect?” And the answer is, not very much.
The base is nice. It’s not just a generic slab of earth, it’s a muddy surface marked with the tracks of other dinosaurs, including a couple of theropods. The base sits nice and flat, and the Apatosaurus sits nice and flat on it, with no rocking at either point of contact. Not only do the feet of the Apatosaurus fit neatly into the sculpted footprints, one of the hindfeet has a little metal rod that slots into a socket in one of the hindfoot prints, to keep the maquette firmly on the base. That means that if you want to display the maquette off the base, you’ll have to either cut off the rod or make sure that your alternative surface will accommodate it.
The skull is…less satisfying. It’s a nice enough rendition of an Apatosaurus skull, and if it had come by itself I would have been very happy with it. The trouble is that the maquette is considerably more detailed, so when the skull sits next to the maquette it suffers by comparison. But what else are you going to do with it? Make a separate shrine to Apatosaurus somewhere else?
The difference in sculpt quality between the maquette and base on one hand and the skull on the other is apparent even on casual inspection. My copies are sitting on a bookcase adjacent to my office door. Sometimes people walking down the hall pop their heads in, and so far the most common comments are that the maquette is “awesome” and that the base is “cool”. People have been genuinely impressed that the base is a realistically detailed chunk of the environment and not just a flat slab. The only people who have commented on the skull have said that it seems “lame” compared to the maquette.
The base is included in the basic package with the maquette, in a limited edition of 500, which as of this writing goes for $289.99 (here). The package with the skull accessory is in an edition of 100, and goes for $299.99 (here). So the skull is only $10 more, and although it is not quite as nice as the maquette, I think it’s a steal at the price. Mine is certainly not going anywhere.
So much for the gross anatomy. You probably noticed that I haven’t said anything about how the maquette is posed or textured or colored. Those will all be topics for next time.
- Baumel, J.J., King, A.S., Breazile, J.E., Evans, H.E., and Vanden Berge, J.C. (eds.) 1993. Handbook of Avian Anatomy: Nomina Anatomica Avium, 2nd ed. Publications of the Nuttall Ornithological Club, No. 23. Cambridge, Massachusetts, 779 pp.
- Czerkas, S.A. 1993. Discovery of dermal spines reveals a new look for sauropod dinosaurs. Geology 20:1068–1070.
- Frey, E. 1988. Anatomie des Körperstammes von Alligator mississippiensis Daudin.
- Gilmore, C. W. 1932. On a newly mounted skeleton of Diplodocus in the United States National Museum. Proceedings of the United States National Museum 81:1-21.
- Janensch, W. 1929. Die Wirbelsäule der Gattung Dicraeosaurus. Palaeontographica Suppl. 7(1), 3(2), 37-133.
- Jensen, J.A. 1988. A fourth new sauropod dinosaur from the Upper Jurassic of the Colorado Plateau and sauropod bipedalism. Great Basin Naturalist 48(2):121-145.
- Paul, G.S. 2010. The Princeton Field Guide to Dinosaurs. Princeton University Press, 320 pp.
- Salgado, L., R.A. Coria, and J.O. Calvo. 1997. Evolution of titanosaurid sauropods. I: Phylogenetic analysis based on the postcranial evidence. Ameghiniana 34:3-32.
November 16, 2011
This is the second in a series of posts in which I review the Sideshow Collectibles Apatosaurus maquette. The rest of the series:
- Part 1: introduction
- Part 3: the neck
- Part 4: body, tail, limbs, base, and skull
- Part 5: posture
- Part 6: texture and color
- Part 7: verdict
First, a note on the photos. There a few minute white flecks on the head in the pictures. These are near-microscopic pieces of styrofoam packing material, which I only discovered after I’d shot the photos–they are, seriously, too small to be noticed otherwise. Just be aware that they are not flaws in the paint. The whole head, from external ear to snout tip, is 35 mm long, which gives you some idea of the quality of the sculpting and painting. The entire maquette is detailed to the same degree.
The general form and proportions are a good match for the skull of Apatosaurus. In particular, the head is roughly rectangular in dorsal view, with a very squared-off snout. Among extant animals, square snouts are typically found among grazers, and grazing on low-growing vegetation has been suggested for diplodocids as well (Stevens and Parrish 1999, Whitlock 2011). It is worth keeping mind, however, that anatomy is not destiny (Smith and Redford 1990); the behavior of living animals is often more varied than their skeletal form might suggest, and in some cases morphological specialization can lead to ecological generalization.
In a paper with direct relevance to grazing and browsing, Feranec (2003: 230) analyzed the diet of the Pleistocene camel Hemiauchenia. He found that “hypsodonty is not strictly associated with obligate grazing; instead it may, in this case, represent an adaptation to widen niche breadth that allowed grazing as well as browsing.” In other words, the tall, long-wearing (hypsodont) teeth necessary for eating tough grass do not prevent hypsodont herbivores from browsing on softer vegetation as well, whereas committed browsers with lower tooth crowns would have a harder time dealing with tough, abrasive grasses.
Sauropods didn’t chew their food, so tall grinding molars are beside the point, but snout shape is not. It is possible that a broad snout widened the niche breadth of diplodocids to allow both grazing and browsing, whereas a narrow-snouted sauropod like Camarasaurus would probably have made a poor grazer. I’m not discounting the hypothesis that diplodocids were partially or even predominantly grazing animals–in particular, it would help make sense of Nigersaurus, which seems to have taken the grazing adaptations seen in other diplodocoids to an extreme. Just pointing out that certain kinds of morphological specializations broaden, rather than narrow, the ecological opportunities of the animals that bear them. I should also point out that Whitlock’s (2011) analysis did not rely on muzzle shape alone but also on some interesting tooth microwear data. That paper is well worth reading, and happily it’s free, so go read it if you haven’t.
Back to the maquette. Several issues of the soft tissues of the head deserve comment.
The nostrils are down near the end of the snout, as predicted by Witmer’s (2001) work on nostril position in extant vertebrates. I know that some people are skeptical about the nostril position in dinosaurs hypothesized by Witmer, but it makes good sense to me. First, in formulating the hypothesis, Witmer did something that none of his critics have done, which is actually establish the nostril position in a wide range of extant animals. By itself, this doesn’t show what the nostril position in dinosaurs must have been, but it establishes a null hypothesis, which should only be discarded if there is compelling evidence to the contrary. And the scarcity of counterexamples among extant vertebrates constitutes a second, normative argument: if the default nostril position was an easy constraint to break, we’d expect to see more taxa that have broken it. (Both of these arguments also apply to the alert neck posture of tetrapods, by the way.)
Second, Witmer’s hypothesis has explanatory power: it makes sense of the troughs and tracks in front of the nostrils in sauropods with retracted nares. These tracks are most clearly expressed in the skull of Giraffatitan (see, e.g., the images at the top of this post), but they are present in other sauropods as well, like the Denver museum Brachiosaurus sp. skull shown above. Witmer’s hypothesis of nostril position made good sense to me because of my experience working on postcranial pneumaticity in sauropods. External pneumatic traces on sauropod vertebrae often consist of pneumatic foramina set inside larger pneumatic fossae (see, for example, this, from here). Similarly, the bony nares of sauropods can be thought of as pneumatic foramina set at the posterior end of the pneumatic fossae formed by the troughs and tracks on the snouts.
One last thing on nostril position in dinosaurs. I’ve seen people argue that terminal nostrils would have been bad for dinosaurs (especially carnivores) because they would have gotten poked by vegetation or fouled with food. To which I can only say, good people, stop trying to figure out dinosaurs from first principles and just look at live animals.
Next item: the teeth are covered by fleshy lips. The hypothesis that some dinosaurs had lips is not new, but it hadn’t received much technical attention until recently. Enter Ashley Morhardt (research page, blog). For her MS work under Matt Bonnan (research page, blog) at Western Illinois University, she did something that no one had done before: she counted nutrient foramina (blood vessel holes) in the jawbones of extant vertebrates and related foramina counts to the kinds of soft tissues the jaws supported: marginal scales, muscular lips, beaks, and so on. Then she looked at dinosaurs and applied what she’d learned. That work is still on the road to publication, so I won’t give away the game. But I did ask Ashley specifically about the plausibility of the lips in the Apatosaurus maquette, and she was kind enough to share her thoughts. She writes (with permission to cite):
The foramina present at the margin of Apatosaurus‘ mouth are more similar in relative size, shape, and distribution to those of crocodylians than those of mammals. … A conservative EPB approach would shy away from reconstruction that might include any type of fleshy seal at the oral margin. This would leave the teeth bare and the posterior margin of the mouth covered in skin without any overhanging scales. … The current maquette is gorgeous, but potentially incorrect.
Ashley is now working on her PhD with Larry Witmer (research page, blog) at the University of Ohio, and we can surely expect more cool science from her in the future. Please also note that the question of dinosaur lips was recently the subject of a long, thoughtful post by Jaime Headden.
Since this post involves soft tissues of sauropod heads, I’m contractually obligated to point out that, like the maquette, real sauropods didn’t have trunks.
Finally, I’m happy to say that the head avoids shrink-wrapped dinosaur syndrome. There’s enough underlying anatomy to show that It’s built up from the skull of Apatosaurus, but you can’t see every little ridge and divot in the skull (nor should you). And the soft tissues are plausible and detailed, so the head doesn’t just look like a smooth bullet of meat. And the sculpting itself is detailed enough to support close examination. All of these are big pluses, even if the lips are a (small) step beyond what our current understanding will support.
- Feranec, R.S. 2003. Stable isotopes, hypsodonty, and the paleodiet of Hemiauchenia (Mammalia: Camelidae): a morphological specialization creating ecological generalization. Paleobiology 29(2):230-242.
- Smith, K.K., and Redford, K.H. 1990. The anatomy and function of the feeding apparatus in two armadillos (Dasypoda): anatomy is not destiny. Journal of Zoology 222:27-47.
- Stevens, K.A. and Parrish, J.M. 1999. Neck posture and feeding habits of two Jurassic sauropod dinosaurs. Science 284: 798-800.
- Whitlock, J.A. 2011. Inferences of diplodocoid (Sauropoda: Dinosauria) feeding behavior from snout shape and microwear analyses. PLoS ONE 6(4):e18304. doi:10.1371/journal.pone.0018304
- Witmer, L.M. 2001. Nostril position in dinosaurs and other vertebrates and its significance for nasal function. Science 293:850-853.