Sauropod Vertebra Picture of the Week

Here’s how my pig skull turned out (prep post is here).

Verdict? I’m reasonably happy with it. As Mike wrote in the post that kicked off the “Things to Make and Do” series, “a pig skull is a serious piece of kit”. It’s big and substantial and it looks awesome sitting on the shelf. I learned a lot prepping it, and in particular I learned a couple of things that I will do differently next time:

1. From now on I will cut the meat off first and grill only that, and not put the skull through the thermal stress of getting dry-cooked. Even with indirect heat, I think smoking the whole head did adversely affect the quality of the bone. The forehead and the rami of the mandibles in particular lost a little integrity. I painted the whole skull with a mix of 50% PVA (white glue, like Elmer’s) and 50% water, so it’s solid, but the surface bone is just slightly rough, I think because of degradation of the cortical bone.
2. Before this I had only prepped small bones–small mammal and reptile skulls, vertebrae and long bones of domestic fowl, cannon bones and hooves of cattle. Stuff like that takes maybe an hour or two max to simmer, and to whiten, and that’s how I approached the pig skull. And it took forever, because I was doing short cycles, which meant doing a lot of them. I did a sheep skull this past holiday break, which I will post about soon, and I learned that the trick with bigger bones is just time. Simmer for 12 hours, not 2 hours, whiten for 2 or 3 nights, not just one. The sheep skull probably took more time from start to finish, but it was a lot less effort, because for much of that time it was just simmering, or soaking in dilute hydrogen peroxide.

With their deep lower jaws, pig skulls look rather lumpen in lateral view. But they look awesome in anterodorsal view, like dragon skulls. Here you can see that the prenasal bone is a little darker and less crisp than the other bones of the face. That’s because it was still ossifying from a big block of cartilage. I scraped off most of the cartilage, but not all, and what remained dried and hardened into an incredibly tough, translucent, slightly yellowish shell. 

I still have two pig heads on ice. I probably won’t do anything with either of them until I get some more time off, but I am looking forward to prepping another pig skull, in part to see how much better I can do the next time. But I’m still happy to have this one. To paraphrase another line from Mike’s old post, this is something that everyone ought to do.

Edit: here are some links about cooking pig heads and prepping skulls.

• Will it Sous Vide?: The Head of a Pig (Lifehacker)
• How to Clean Animal Bones So You May Proudly Display Them in Your Home (Lifehacker)
• Why Pig’s Head Should Headline Your Next Cookout (Thrillist)
• Porchetta di Testa – Pig’s Head Roulade (West Coast Prime Meats)

This is something I did over Thanksgiving break in 2019. I meant to blog about it sooner, but you know, 2020 and all. So here I am finally getting around to it. (Yes, I know the ruler in the above photo is the worst scale bar ever. I was, uh, making a point. Which you got. So go you!)

For reasons unknown to me, the strip of skin between the mid-snout and the ear on the right side of the head was already off when I took possession from the local butcher. But it did show the ear muscles to good advantage, as well as the parotid gland–the knobbly white thing between the eye and ear that looks like grits, or eggs, or white beans. You have a parotid gland in front of each of your ears, too (par-otid = “next to ear”), each with a duct that crosses the cheek to bring saliva into your mouth. If you push your tongue into the upper-lateral “corners” of your cheeks, you can feel the little papilla where the duct opens, and if you push against the papilla with your tongue you may feel a little saliva leak out. You also have paired submandibular and sublingual salivary glands, but those will have to wait for another day.

Here’s the head from the back, after I’d gotten the right ear off. The bluish-white hyaline cartilage over the occipital condyles is clearly visible about 2/3 of the way up from the bottom, with the faintly yellowish stump of the medulla oblongata in between, going up into the braincase. Tons of neck muscles are visible here, and maybe someday I or someone else will get around to labeling them in this photo–but it is not this day.

What was I doing here? Getting off the ears, and as much skin and subcutaneous fat as possible, in preparation for brining and smoking. I like this photo, the little piggy looks positively happy about having its skull prepped.

Right, into the bag with you then. I did the same brining and smoking routine that I did for my first smoked turkey back when–see this post for details.

And here we are about 15 hours later. Note how much the color of the meat has changed from the brining.

Time to extract the brain. I already showed a version of this photo in my post on the $1 brain-extractor (a.k.a. drain rooter, see this post), but it bears repeating: the brain is mostly lipids and if you cook the head with the brain still in it, the brain will turn into liquid fat and seep into the bones and you’ll spend the rest of your days trying to degrease the skull before you die, unloved and weeping, on a pile of rags. So no matter how you’re planning to cook the head, yoink the brain first.

Onto the grill, with a drip pan underneath, foil heat shields in place to keep the heat indirect, and foil-wrapped mesquite smoke bombs visible under the grill, right on top of the coals. This is about all I do with my grill anymore; smoking is really no more work than anything else and the results are pretty much to die for. YMMV.

Same shot an hour later and the smoking is coming along nicely. I ended up smoking this head for three hours, an hour and a half on each side. 

And into the roasting pan for a few minutes’ rest at the end of the cooking. And it was cooking, not just specimen prep–we ate this pig head in lieu of a turkey for Thanksgiving, and it was amazingly delicious. One thing to note in this photo is how the temporalis fascia has pulled away from the skull at the upper left, exposing some bare bone. This would be a problem later on.

Defleshing, both to get the edible meat off, and to get as much of the rest of the soft tissue off in preparation for simmering. In this anterior view, you can see that the right side of the animal’s forehead (viewer’s upper left) got exposed during the smoking process and the bone is stained brown. 

Even with the meat cooked all the way through, disarticulating the jaw took some doing, and then some follow-up meat removal. Check out the very round, almost hemispherical mandibular condyles, which fit up into the sockets of the temporomandibular joints. Birds and other reptiles mostly do it the opposite way, with rounded quadrates on the cranium that fit into articular sockets on the lower jaw.

Ready for simmering. Pro tip: if you need a really big metal pot in which to simmer skulls or other large osteological specimens, but you don’t want to go bankrupt, look for a tamale-steaming pot. They’re comparatively thin-walled and lightweight, but still plenty sturdy for just about any application you are likely to think of. 

Our kitty, Moe, helped with the clean-up of the roasting pan.

The first simmer. At this remove, I don’t remember how many rounds of simmering I did, but it was at least two, maybe three.

Post-simmer, I put the skull into a sink-full of warm, soapy water for a defleshing. Notable bits you can see on the right side of the photo are the ridged surface of the palate (about 7:00 on the plate), the long straight cartilage of the nasal septum (going vertically up the right side of the plate), and the incisors at the extreme upper right, sitting on the edge of the sink. Most of the incisors fell out during the wash, which was fine, because most of them were horribly stained from the smoking process and would require a lot of scrubbing and bleaching to get back to a nice and natural-looking white.

The condition after the first simmer. You can see that the supraorbital foramina, on the forehead between the eyes, still have goop in them. This was true of pretty much all of the nerve and blood vessel passages. It took a lot of time, some ingenuity, bamboo barbeque skewers, and running water this way and that to flush out all of that crud. And the bones are still weird colors at this stage, pre-whitening, especially the groady dark patches on the forehead. It wasn’t the areas of bone that were directly exposed to smoke that were the problem, it was the areas just adjacent where the periosteum cooked against the bone.

Same stage, left lateral view. Note the empty sockets for the incisors, and the infraorbital foramen (above the upper teeth and about a third of the way between eye socket and the nose), which on this side is divided in two by a strut of bone. There’s another gross dark patch on the back of the zygomatic arch. All of those took pretty aggressive scrubbing to remove.

Back into the pot for another simmer. The perforated plate at the bottom sits on a lip of metal about three inches above the bottom of the pot so you can steam tamales with this thing. I used it to keep the bones off the bottom of the pot so they’d have no chance of getting scorched.

Here’s a significant jump forward in time. By this point I’d degreased and whitened the skull by soaking it in dilute hydrogen peroxide (I use the cheap stuff from the dollar store down the street, and it works fine), applied glue to several of the skull sutures that were threatening to come apart, and epoxied the prenasal bone back into position between the nasal bones above and the premaxillary bones below. The prenasal bone is a pretty cool structure, you can see it in other views (including a cross-section!) in this post. I also glued the incisors back in at this stage.

Believe it or not, this was the largest skull I had ever prepped myself–the largest osteological preparation of any kind, in fact–and it was a lot more work than I anticipated. But the effort was worth it, and now I have a really cool pig skull on my bookcase. I’ll show the finished skull in a follow-up post (no, really, I will!). EDIT: And I did! 

For other posts on pig skulls, see:

• Things to Make and Do, part 1: Pig Skull (off-topic)
• What half a pig head looks like
• Here’s that pig-skull multiview you ordered
• Why do some domestic pigs have foreheads?