April 10, 2013
This is a caudal vertebra from the middle of the tail of an ostrich, LACM Bj342:
The middle row shows it in anterior, left lateral and posterior views; above and below the anterior view are the dorsal and ventral views. It’s about 5 cm across the transverse processes. (This figure is from a manuscript that Matt and I will submit to a journal probably within 24 hours.)
In compositing the different views, I had a heck of a time recognising what was what. The dorsal view looks so much more like what we’d expect a ventral view to look like — indeed, the two are more similar for this vertebra than for any other I’ve seen.
How about those big pnuematic foramina right at the top of the bone? At first, Matt and I thought we’d never seen anything like that before. But then we realised that we sort of had — in a cervical vertebra of Apatosaurus which appears as part one of Taylor and Wedel (2013: figure 9).
This is Apatosaurus sp. OMNH 01341 in right posterodorsolateral view. “las” marks a ligament attachment site — a big, baseball-sized rugose lump — and right next to it is a pneumatic foramen, marked “pfo”.
Just like this, the ostrich caudal is a saurischian vertebra with a bifid neural spine, and with pneumatic foramina within the intermetapophyseal cleft.
June 12, 2012
More from my flying visit to the Harvard Museum of Natural History. I found this exhibition of bird eggs very striking. In particular, it was shocking how much bigger the elephant-bird egg is than that of the ostrich.
From smallest to largest, the eggs are those of:
- Ruby-throated Hummingbird Archilochus colubris
- Common Redpoll Carduelis flammea
- House Finch Carpodacus mexicanus
- Eastern Screech Own Megascops asio
- Thick-billed Parrot Rhynchopsitta pachyrhyncho
- Red-necked Grebe Podiceps grisegeno
- Magnificent Frigatebird Fregata magnificens
- Red-tailed Hawk Buteo jamaicensis
- Cackling Goose Branta hutchinsii
- Bald Eagle Haliaeetus leucocephalus
- Tundra Swan Cygnus columbianus
- Wandering Albatross Diomedeo exulans
- Ostrich Struthio camelus
- Elephant bird Aepyornis sp.
As always, click through for full resolution.
March 14, 2012
Another picture from the recent ostrich dissection (click for full-size, unlabeled version). Last time we were in the middle of the neck, looking from anterior to posterior. This shot is from closer to the base of the neck, looking from posterior to anterior. A lot of the stuff is the same: the ragged cut from the saw at the meat processing plant where the ostrich was cut up; the spinal cord with the supramedullary airways above it in the neural canal; and the large interspinous ligament with diverticula on either side. We’ll have reason to refer back to some of those things in the not-too-distant future, but right now I want to draw your attention to something else: the tendons of the paired longus colli dorsalis muscles toward the top of the photo.
Here’s a modified version of Wedel and Sander (2002: fig. 2) with the course of the longus colli dorsalis highlighted in red (anterior is to the left). It is a curious aspect of bird necks that the large dorsal muscles do not insert on the neural spines but on the epipophyses (or dorsal tori or dorsal tubercles) above the postzygs. A naive approach based on beam theory would suggest that inserting on the neural spines would give those muscles more leverage, but necks are tricky and often defy such a priori predictions.
Instead of inserting on the neural spines, the longus colli dorsalis muscles originate from them, especially in the posterior part of the neck, and that’s what the photo at the top shows. From the reader’s point of view, the big interspinous ligament runs forward to attach to the posterior side of the neural spine (not visible because it’s buried in gloop, but it’s about a third of the way down from the top). The longus colli dorsalis tendons are running forward from the anterior side of the neural spine.
Here’s the same thing again, also in an ostrich, but in an MRI this time (and with anterior to the right; Wedel et al. 2000: fig. 20). The dark streaks running forward from the neural spines are those longus colli dorsalis tendons. The interspinous ligament also shows up nicely as a series of white bands connecting adjacent neural spines.
- Wedel, M.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, M.J., R.L. Cifelli and R.K. Sanders. 2000. Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon. Acta Palaeontologica Polonica 45(4): 343-388.
March 10, 2012
Those ostrich necks I went to Oro Grande to get last Thursday? Vanessa and I started dissecting them last Friday. The necks came to us pre-cut into segments with two to three vertebrae per segment. The transverse cuts were made without regard for joints so we got a bunch of cross sections at varying points through the vertebrae. This was fortuitous; we got to see a bunch of cool stuff at the cut faces, and those cut faces gave us convenient avenues for picking up structures and dissecting them out further.
In particular, the pneumatic diverticula in the neck of this ostrich were really prominent and not hard at all to see and to follow. The photo above shows most of the external diverticula; click through for the full-resolution, unlabeled version. The only ones that aren’t shown or labeled are the diverticula around the esophagus and trachea (which had already been stripped off the neck segments, so those diverticula were simply gone), those around carotid arteries, which are probably buried in the gloop toward the bottom of the photo, and the intermuscular diverticula, of which we found a few in parting out the dorsal and lateral neck muscles.
There is one final group of diverticula that are shown in the photo but not labeled: the interosseous diverticula that fill the air spaces inside the bone.
We have tons of cool photos from this dissection, so expect more posts on this stuff in the future.
For previous posts showing diverticula in bird neck dissections, see:
Things to Make and Do, part 7b: more fun with rhea necks (admittedly, not the most creative title ever)
March 8, 2012
March 2, 2012
Today was one of the most interesting days of my life.
Vanessa and I needed ostrich parts for dissection, so I had gotten in touch with Doug Osborne of OK Corral Ostrich Farms in Oro Grande. That was on the recommendation of Andy Farke, who got a bag of ostrich heads from Doug a couple of years ago (those heads are in the other Dr. Wedel’s research freezer, waiting for an ostrich head boiling party). I made plans with Doug to meet him at the farm at 9:00 this morning (Thursday). He warned me that it would have to be a quick visit because he was having a big load of hay delivered at 9:30 and he’d have to go supervise the unloading.
Oro Grande is 60 miles from Claremont and Pomona, in the high desert on the north side of the San Gabriels. I left here at 8:00 and rolled up to the marked parking area right at 9:00.
And immediately I could tell that things had not gone as planned. There were two hay trucks in the big ostrich paddock (post-Jurassic Park, any large outdoor enclosure for theropods must be referred to as a paddock), so the hay had clearly come early.
More worryingly, the gate at the corner of the paddock was open and the ostriches were starting to get out.
I should stop here and mention a couple things. First, when I heard about OK Corral Ostrich Farms I assumed it was like almost every other ostrich farm in the United States: a side-business on a small farm involving a few dozen birds at most. It is emphatically not. Doug has 2500 ostriches, 2000 at Oro Grande and another 500 at a ranch in Elsinore; his operation is the largest ostrich ranch outside of Africa. The ostriches at Oro Grande are not all in the main paddock, but several hundred of them are, and these were starting to trickle out of the open gate when I rolled up.
Second, the open gate wasn’t the fault of the guys in the hay trucks. Doug later determined that the padlock had clicked but failed to engage when one of the ranch hands shut the gate behind the trucks. Stuff happens. He told me it was his first break-out in seven years.
Anyway, when I hopped out of the car there was one ostrich out, but more were moving that way. Fortunately Doug and I had been corresponding by phone so I had his number in my cell. I called him and told him what was up, and he told me to get back in my car (for reasons that will become apparent later on). A few minutes later he rolled up in his pickup, and by that time about a dozen birds were out, including a couple of males.
I jumped out to say hi. I hadn’t been real wild about waiting in the car in the first place. It was clear that getting the ostriches back in the paddock was going to be at least a two-person job, because one person would have to keep each batch of returning birds from running off while the other opened and shut the gate. I told Doug that I had grown up in the country and had to herd cattle before so he’d know I wasn’t as useless as I probably looked. (I hadn’t checked the weather, the temperature was in the 40s F, with a west wind gusting around 40 mph, and I was wearing my ODP t-shirt and no jacket.) He sized me up for about two seconds and said, “Okay, I’m going to start giving you orders.”
And for the next 30 or 40 minutes, that’s what he did. Singly and in groups of two and three, we got all the stray ostriches rounded up and back in the paddock. I’m sure for Doug it was a pain in the arse, having a dozen large, fast, expensive birds on the wrong side of the fence.
For me, it was 100% awesome. I love ostriches. I’ve dissected them, CTed them, measured their bones and sawed them open, looked at their intervertebral joints, eaten their meat, and watched them for ages in zoos, but this was my first experience on the ground with no fence between me and them.
Ostriches are freakin’ huge. I had only dissected babies, or adults piecemeal. It’s one thing to read about how big they are or watch one in a zoo, and quite another to have an 8-foot-tall, 350-lb male ostrich standing 4 feet away, clearly thinking about how freedom is on the other side of this slow, puny, annoying mammal. Doug coached me through flapping my arms and shouting “Ho! Ho! Ho!” and sometimes just getting up in their space and slapping them on the ass. He was keeping a weather eye on them for any aggressive behavior, and I was vacillating between bio-geek squee and healthy fear.
After the ostriches were all back in the paddock, the hay trucks were safely out, and the ranch hands had gotten a stern word about double- and triple-checking the padlock, Doug invited me in for a cup of coffee and we had a nice long chat.
Doug’s an interesting guy. He used to be a Wall Street millionaire, in the executive stratosphere of Merrill Lynch. One year he bought his mother four ostriches as a present. Those ostriches started breeding, his mom started selling them, and Doug realized that there was a living to be made farming ostriches and decided that was more appealing than working on Wall Street. He’s been doing this for 20 years.
As a farmer he has a refreshingly unromantic view of his birds. He loves ostriches, obviously, otherwise he wouldn’t have made a career out of them, but his love for them is grounded in practical matters like cutting the strings off the hay bales so the birds can’t accidentally strangle themselves. To him the birds are interesting but not exotic, and for me it was fascinating to talk with someone who raises them from the egg and works with them every day.
Speaking of eggs, after coffee it was time to go gather them from the paddock. It’s still too early in the season for the females to be laying many, but there were a few. By this time Doug was treating me like one of the team. He gave me an OK Corral trucker hat as a thank-you for my help with the ostrich-wrangling, and I got to ride along on the egg-collecting expedition. There was one small and probably communal nest of half a dozen eggs, and as we drove around the paddock we spotted a couple of isolated “rogue” eggs. The ranch hands gathered most of the eggs, but after they’d gone off to secure the hay I got to get out and pick up the last rogue egg. It was surprisingly heavy, like a shot put, and Doug gave me the same directions I give to students carrying human skulls: “Hold it securely in two hands, all the way to the box.”
I got to see some interesting behavior. The big males would come right up to the pickup, make dominance displays, and snap at us. The truck was dented from having been kicked by ostriches who didn’t want to share their considerable space (the paddock is probably between an eighth and a quarter of a mile on its long axis). Last year Doug was moving birds around and a big male kicked him hard enough to puncture his abdomen and lacerate his liver; he spent two weeks in the hospital. That’s why he wanted me to stay in the car when I first rolled up, and why he didn’t ask for help herding birds until he knew that I had some prior experience moving big animals around.
Oh, way back at OU I had read about ostriches having sizable penises, and I can now attest to that as an eyewitness. One of the males flopped his out in front of the truck and it was about the same dimensions as my arm below the elbow. Elsewhere in the paddock I saw a male and a female working together to make zygotes*.
*That’s biologist-talk for “gettin’ their gangly theropod freak on”.
Back at the ranch house the eggs went into the incubator, Doug went into the walk-in freezer to get the ostrich necks I was there to buy, and I got a few minutes to just wander around and gawk. In addition to the ostriches Doug has about 50 emus in a separate pen, and roaming loose in the big fenced and gated area around the ranch buildings are turkeys, chickens, peacocks, and geese. Three tom turkeys–Los Hermanos Mariachis, Doug calls them–followed me around, puffing up and showing off. I could see some signs of interspecific socialization: the geese hung out with the turkeys by the ranch house, while the peacocks and chickens claimed the area around the little red building where the empty, blown-out eggs are stored. Doug talked about how the “Goose-waffe” would fly down the driveway in formation and use the open truck-shed as a hangar.
My last encounter of the day was also my favorite. Abigail is a tame female ostrich who wanders around the yard with the smaller birds. She broke her ankle when she was a baby, and rather than put her down Doug nursed her back to health (I told you he loves ostriches). She’s quite even-tempered and he said she would tolerate being hugged and petted. So while Doug finished up a last bit of farm business before he could escort me out to the gate, I hugged and petted Abigail. She is my height and my weight, but because her neck and legs are so long and skinny almost all of that weight is concentrated in her torso, which is very bulky and solid. Abigail pecked at my watch a few times and then ignored me; with all the petting and hugging she probably assumed I was an oversized and somewhat slow-witted child. That’s her on the right in this pathetically undersized photo.
I have two regrets from the day. First, the only camera I had along is the crappy one in my POS (positively old school) cell phone, which is why these pictures are few and mostly sucky. More sucky still is that Vanessa missed the ostrich wrangling. She had master’s program responsibilities today and I thought (and Doug thought) this would be a quick stop of just a few minutes to get some necks, not a three-hour ostravaganza. Doug invited us back for a proper tour sometime, and we will definitely go, but unless something goes terribly wrong there won’t be any more ostrich-herding opportunities. I feel like I got in on all the fun.
Previous SV-POW! posts on ratites, from our Things to Make and Do series:
- Part 6: fun with ostrich heads
- Part 6b: Veronica the ostrich head starts to come to pieces
- Part 6c: fragments of ostrich skull
- Part 6d: Veronica the ostrich skull, laid bare
- Part 6e: gloat your eyes, feast your soul, on my ostrich ethmoid ossification
- Part 6f: my dumb observation of the day is that in dorsal view, a partly-assembled ostrich skull looks kind of like a chasmosaurine
- Part 7: fun with rhea necks
- Part 7b: more fun with rhea necks
Elsewhere on the web, Darren has blogged extensively about ratites at Tet Zoo. Dissecting Ozbert the ostrich is a good place to start, and that post has links to several others.
Finally, all of my pre-SV-POW! ratite stuff is linked from the ratite clearing house post on my old blog.
Things to Make and Do, part 6f: my dumb observation of the day is that in dorsal view, a partly-assembled ostrich skull looks kind of like a chasmosaurine
July 24, 2010
What’s that? You want proof, you say? Well, I find your lack of faith disturbing; but since you asked, you got it!
What we have here is the part-way assembled skull of our old friend Veronica, in dorsal view, with anterior to the left. The long pointed bones down there are the nasals: you don’t see their anterior ends in complete skulls because they’re covered by the fused premaxillae. Posterolateral to those are the lacrimals, forming those posterolaterally directed spurs. Between the nasals towards their posterior end is the top of the mesethmoid. Behind the nasals and mesethmoid are the frontals, the largest bones on view here; and behind those are the parietals. Ventral to those superficial bones are the palatines (sticking forward and showing on either side of the nasals), plus the pterygoids, the squamosals, and of course the braincase including the parasphenoid rostrum and fused vomers, but those are all hidden in this dorsal view.
Here’s the whole hill of beans in ventral view: this time you can see the parasphenoid rostrum going down the midline, with the vomers fused onto its anterior end; and the pterygoids attached near the base of this process, and the palatines extending anteriorly from them. In this view, the squamosals are the lateralmost projecting bones. Zoom through to the full-sized images to see the cool pneumatic openings up inside the squamosals and the parts of the braincase that they articulate with.
Still waiting to be attached to the cranium: the quadrates (which go on the lateralmost points of the skull); then the quadratojugal, jugals and maxillae, forming a straight line directed anteromedially from the point of the quadrate; and finally the fused premaxillae which go on the end of the snout and join the nasals medially and the maxillae laterally. Those bones will of course obscure some of what we can see at the current stage of assembly, so I thought it would be useful to show you this intermediate stage.
Since I’m here, I may as well show you how the partially reassembled cranium looks in left lateral view, too:
From here, you can really appreciate the weird shape of the lacrimals, with their ventrally directed processes that I think are going to contact the maxillae once I’ve got them attached.
Finally, those of you who have been wise enough to get hold of some red-cyan anaglyph glasses will be able to appreciate this spectacular 3D view of the skull in ventral view. The rest of you: come on, sort it out: they cost maybe a couple of bucks, and they’ll revolutionise your perception of, well, anaglyphs.
Things to Make and Do, part 6e: gloat your eyes, feast your soul, on my ostrich ethmoid ossification
July 19, 2010
Work continues apace with Veronica, my tame ostrich. (See previous parts one, two, three and four). I’ve been photographing the individual bones of the skull — a skill that’s taken me some time to get good at, and one that I might do a tutorial on some time, to follow up the one on photographing big bones.
Here is a preview of the result of this photography-fest: a multi-view figure of the ethmoid ossification.
The top row shows it in dorsal view; the middle row in left lateral, posterior, right lateral and anterior views; the bottom row in ventral view.
This is a midline bone, or rather complex of bones, that lives between and slightly ahead of the eyeballs, as shown in the photographs of part 6c. The top part is the mesethmoid, which contributes to the roof of the skull between the nasals and ahead of the frontals. Below that is — well, I’m not sure what it’s called. Jaime said in a comment that it’s “a portion of the ossified interorbital septum”, but it’s not like a septum: it’s a hollow capsule with very, very thin walls. Anyone know its proper name?
By the way, I strongly encourage you to click through the image above and see it in its full high-resolution (5943 x 3384) glory. As a taster, here’s a small segment — the rear portion of the dorsal view — in half resolution:
As you can see, that’s some very well textured bone — much more so than is apparent to the naked eye.
Cleaning and bleaching is complete! Here are all the bones of Veronica’s skull [see earlier part one, part two and part three], laid out as they were in life (though of course much more widely separated), all in dorsal view:
On the left, we have the bones of the lower jaw, palate and braincase, with the first three and a half vertebrae at the bottom. At the top is the mandible, which is intact on the left side but has separate articular, angular and surangular on the right; between the mandibles are the hyoid bones, of which one of the cartilaginous extensions has survived. Behind those on the midline are the fused vomers, parasphenoid rostrum and braincase, all fused together. Alongside this element are the palatines and pterygoids, and to the right of those are the midline supporting cartilage and mesethesmoid ossification. Behind the braincase are the first three and half vertebrae of the neck.
On the right, we have the superficial bones. Reading down from top to bottom of the midline, we have the premaxilla, nasals, lacrimals, frontals, parietals, and (out towards the sides) squamosals; from top to bottom down the sides we have the premaxilla (again), maxillae (the left one broken in two), the jugals and quadratojugals (which are still fused together on the right) and finally the quadrates.
That’s everything! My next tasks are:
- Repair the three broken bones: left maxilla, left posterolateral process of the premaxilla, and left lacrymal.
- Photograph every individual bone from all six cardinal directions and maybe some interesting oblique angles.
- Put the skull back together.
- Photograph the entire skull, including 3d anaglyphs.
Then I think I’ll be done.
Special bonus encouragement
A few articles back, Zach Miller commented:
You lucky bastard! First a monitor lizard, now this? I’ve really GOT to get some kind of deal going with my local zoo. :-)
Lucky? Nothing to do with it! One of the points I keep meaning to make in the Things To Make And Do series is how very much this is something anyone can do. Well, OK, I admit I was super-lucky to score the monitor lizard; but I got the pig’s head by walking into a butcher’s shop and saying “One of your finest pig’s heads, please, my stout yeoman!”. I got Veronica by googling for “ostrich farm” and emailing the ones in the UK asking whether any of them had any heads to spare. I urge you, and anyone else who loves anatomy, to do the same.
Anyone can do this! You don’t need qualifications, or even experience; this is how you get experience. Seriously, I’ve learned ten times more about dinosaur skulls in the last week from playing with Veronica than I did in the last five years of feeling guilty that I never read any head-related papers.
June 28, 2010
For reasons that seemed good to me at the time, I took my best shot at photographing the right cervical rib from cervical vertebra 3 of my ostrich, Veronica [see earlier Part A, Part B and Part C for context]. I thought you might like to see the result, so here it is:
For some reason, cervical ribs don’t seem to get a lot of love in the literature: the only paper I know that figures them in half-decent detail is Osborn and Mook’s classic (1921) monograph on Camarasaurus, and even there, the job is done in rather a half-hearted fashion. I’m planning to buck this trend by properly figuring the cervical ribs of the Archbishop when I finally get around to finishing that paper, and I included a sneak preview of the rib that I’ve arbitrarily designated X1 a while back. It’s instructive to compare that illustration with this one. In fact, here it is again:
Update (the next day)
It occurs to me that I should have composed the ostrich-cervical-rib illustration in the same orientation and order as the Archbishop one, for easier comparison. So that’s what I’ve done below. Since the Archbishop rib X1 is from the left side, I’ve also flipped the right-sided ostrich rib to match. Here it is: