For reasons that would be otiose, at this moment, to rehearse, I recently found myself in need of a hemisected turkey cervical. Happily, I own five skeletonised turkey necks, so it was with me the work of a moment to select a candidate. But now what? How to hemisect it? We have  discussed plenty of hemisected things here at SV-POW!, but they tend to have been produced using heavy machinery such as a band saw: something that I singularly lack.

SPOILER: I found a way. Here is a domestic turkey Meleagris gallopavo domesticus, 9th cervical vertebra, hemisected, in right medial view. Read on to discover the extremely high-tech approach that yielded this prize. It’s propped up on some kind of turkey bone to help me get a good medial perspective, I am thinking maybe the pygostyle?

One idea was to use an angle-grinder: not to cut down the midline of the vertebra — it would be much too blunt and powerful for a small, delicate vertebra — but to use as a sanding surface, locking the grinder in place and holding the vertebra up against the spinning plate. That might work well, assuming I could find a way to secure the angle grinder safely, but as it happened my need for a hemisected vertebra came up during a power cut. (Thanks, Storm Eunice!)

So I did it the way the Amish do their vertebral hemisections: by hand, simply by rubbing the vertebra against a sheet of sandpaper:

CT scanning: the Amish method.

This is not as laborious as you might think. I used a single sheet of medium-grade sandpaper, and it took maybe 15–20 minutes. And I just rubbed back and forth while exerting downward pressure. Initially I worked my way only through the prezygapophyseal ramus, which is the part of the turkey cervical that extends the furthest laterally. Once I was satisfied that the plane between eroded prezyg and the intact postzyg was parasagittal, I just kept the vertebra parallel to the sandpaper and kept rubbing. (Sorry I didn’t think to get a photo at this stage.)

One thing that took me by surprise is that there was so very much bone dust. I mean, I am an idiot that this surprised me, since the whole purpose of this exercise was to reduce one half of this vertebra to bone dust. But the lesson to be learned here is to do it on the easily-cleaned bathroom floor — not on the desk next to the computer keyboard and above a carpet. Learn from my mistakes, folks!

Anyway, after some work on the prezyg/postzyg pair, here’s how the vertebra was looking:

You can see straight away that the prezyg ramus, postzyg ramus and parapophyseal ramus are extensively pneumatized, honeycombed with small, irregular air-spaces. In this image it looks like the region of bone between the pre- and postzygs is much more solid, but this is an illusion: what we’re seeing here is a section through the cortical  bone of the neural arch, cut parallel to the surface. Let this be a warning not to over-interpret individual slices of CT-scans!

Once we get a little deeper, we see that the whole wall of the neural arch — and indeed the centrum and the neural spine — is honeycombed, just like the zyg rami:

Now we have another area of what I’m going to call Phantom Apneumaticity: the posterior part of the centrum looks like solid bone, apart from a few pneumatic spaces in the posteroventral extremity. Again, this is an illusion.

Here’s the next place I stopped:

Here, the Phantom Apneumaticity is even more striking: seeing just this as a CT slice could easily mislead someone into thinking that almost the whole of the posteroventral part of the centrum is solid bone. But again, it’s just that we’re very close to the surface of the bone, and seeing a slice parallel to that surface.

This last image also shows an important point of technique: there is a low convex ridge running across the phantom apneumatic area from the top of the cotyle to the base of the centrum. This is where I had changed the angle I was holding the vertebra at, so I accidentally sanded the posteroventral part of the vertebra more than the rest. I found that it was important during this process to keep checking the angles, and to adjust: making sure I wasn’t sanding more from the front than the back, or from the top than the bottom, or leaving a ridge like this.

Also in this last photo you can see that I was just beginning to break through into the neural canal: the anterior part of it is now exposed, between the anterior part of the neural spine and the anterior articular surface. At this stage I sighted along from in front to get a sense of how much further I had to go:

Domestic turkey Meleagris gallopavo domesticus, 9th cervical vertebra, most of right side removed, in anterior view with dorsal to the right. Propped up on the coracoid of a different, larger, turkey.

Quite a way, I guess. Here it is rotated and cropped, so you can more easily recognise it:

Domestic turkey Meleagris gallopavo domesticus, 9th cervical vertebra, most of right side removed, in anterior view. You can see that the neural canal is still mostly intact.

More sanding was required. I sanded some more.

You’ve already seen the final result up at the top of the page, but here is a cleaned-up version of that image, oriented according to Definition 3 of Taylor and Wedel (2019):

Domestic turkey Meleagris gallopavo domesticus, 9th cervical vertebra, hemisected, in right medial view.

And if that isn’t beautiful, what is?

The exciting thing is, anyone can make one of these. Matt’s already explained how to extract and clean up bird vertebrae and given you some ideas of what to do with them. Prepare out some turkey vertebrae and get going with the sandpaper!

I leave you with one more image: the hemisected vertebra in anterior view, oriented with dorsal to the top, and mirrored so it make up a complete vertebra once more. Enjoy!

References

 

Turkey skeleton audit

February 16, 2022

Back in at least 2008 — maybe earlier — I kept all the bones from our good-sized Christmas turkey. Of course, it’s missing the head, neck and feet, but otherwise it’s pretty much all there. (I may also have the neck, but if so then it was supplied as a separate item, and prepared separately.) Here is the box of postcervical bones:

Postcervical skeleton of a mature domestic turkey Meleagris gallopavo domesticus, complete except for feet.

As I was transferring them to a better box today, it occurred to me to lay them  out and see how much sense I could make of them. Here’s what I did with the bones I was happy about:

Postcervical skeleton of a mature domestic turkey Meleagris gallopavo domesticus, complete except for feet. Some small bones omitted (see below). Laid out roughly as in life, in dorsal view.

I should  have put something in the photo to act as a scale-bar, because it’s not apparent from this photo that a turkey is a pretty big thing. From top to bottom of the skeleton as I laid it out here is about 90 cm.

Here are my (in some cases tentative) identifications of the bones:

Postcervical skeleton of a mature domestic turkey Meleagris gallopavo domesticus, complete except for feet. Some small bones omitted (see below). Laid out roughly as in life, in dorsal view. Bones are tentatively labelled. DO NOT USE FOR TUTORIAL PURPOSES.

Are there any obvious mistakes in there? And have I got any of the bones left-right reversed?

Now, here are all the other bones that I was less confident about the positions of:

Postcervical skeleton of a mature domestic turkey Meleagris gallopavo domesticus, complete except for feet. Small bones only.

On the left of course we have the dorsal ribs, but I’ve not been able to arrange them all into near pairs, nor figure out what order I should impose on the pairs that I do have. I’m not even sure how many pairs I should have. On the right are other paired bones whose identity I can’t figure out. I am guessing that the longer ones are probably sternal ribs and that the irregularly shaped ones might be parts of the wrist, but I would welcome corrections and clarifications. Finally, the middle column contains the bones whose idea I have little or no idea about, and which don’t appear to be paired. Any ideas?


By the way, I found this image useful in figuring out the identities of the appendicular bones:

Skeletal reconstruction of a domestic turkey, published in 1808. Source unknown (leave a comment if you can identify it).

And this one useful for the bones of the wing and especially the hand:

Human and bird arm skeletons compared. Source unknown.

More from this skeleton another time!

Last week, while Fiona and I were out walking, we noticed a decaying roadkill badger a bit over half a mile from our house. Yesterday we were out walking again, and we saw that it had decayed to the point where there was not much to the flesh at all. I prodded it with my foot and found that the skull was about ready to come away.

So when we got home, I popped straight back out in the car with some plastic bags which I used as improvised gloves, found the badger, managed to pull its head away from the remaining connective tissue (not a pleasant process) and bring it home. I simmered it gently for a couple of hours — outdoors on a portable hob, I’m not a barbarian — then cleaned it with a toothbrush and left it to cool. Today I soaked it in a soapy water for a couple of hours, then rinsed it off and soaked it in very diluted bleach for a couple more, taking care to harvest all the loose teeth that came out during each stage. Finally I rinsed it off, and here it!

European badger Meles meles, skull in left lateral view, with teeth. Pound coin for scale.

What next? I’ll give it couple of days to dry properly, then figure out which teeth go in which sockets and glue them in place. Then, bam, I have a second badger skull to go with my first, and I’ll be in a position to directly compare two skulls of the same animal.

This is a really nice, quick process compared with most of my preparations. The trick is to find a carcass that has already gone through the nastier stages of decomposition.

Note that the jaw is articulated, by the way. Unlike most animals, the skull of the badger locks the jaw in place with unusual joints in which the mandibular fossa of the cranium wraps around the cylindrical articular condyles of the jaw. I’ll try to include photos next time.

I leave you with a cheap-and-cheerful 3D anaglyph of the skull. Did I ever mention that you should get some cheap 3D glasses? You should get some cheap 3D glasses.

For reasons that I will explain in a later post, I am parting with one of my most treasured possessions: the badger skull that I extracted from my roadkill specimen four years ago.

As a farewell, I finally photographed it properly from all the cardinal directions, and prepared this multiview:

Don’t forget to click though for the full resolution version!

Otters are a “near-threatened” species in the UK, so it’s a tragedy when one is killed by a car. That said, when a roadkill otter is spotted by a friend and delivered to me five days after Christmas, that goes some way to redeeming the tragedy.

So far as I can determine, while otters are protected by law in the UK, there’s nothing saying that a roadkill otter can’t be kept for scientific purposes. So here is Eleanor the dead otter:

It shouldn’t come as a surprise to me, but it does, to find that an otter is a pretty substantial animal. Mine measured at 111 cm from snout to tail, and 69 cm from snout to the base of the tail. Here’s where I considered the base of the tail to be:

Maximum girth is difficult to measure. I ended up taking three measurements: when the tape is left relaxed around the torso, it yielded 50 cm; when I tightened it as one does with a belt, it came down to 44 cm; and I judged that 48 cm was the best true value.

The animal masses about 7.6 kg — including the neglilgible weight of two Lidl carrier-bags that I wedged it into. That compares with 5.2 kg and 100 cm total length for a fox that I buried ten years ago, and a very impressive 12 kg and 75 cm for a badger of the same vintage. (These are not the same fox and badger that I decapitated a while ago, but from memory they were about the same size.)

Like the badger — though not to the same extent — the otter is a serious piece of animal. It has short, heavily muscled forearms that I would not want to be on the wrong end of:

Its head is not obviously damaged, but with its eyes closed and its mouth clamped shut in rigor mortis, there’s not much to see at this stage:

That will obviously change when I get its skull out — but that is a project for the spring. It’s too cold and nasty outside for this kind of work. For now, Eleanor will rest in peace in our woodshed.

An otter is a rare find, and I have no expectation of ever acquiring another one — unlike foxes and badgers, which crop up maybe once a year or so on average. So I hope I can make the time to treat this with the reverence it deserves, and extract the whole skeleton (as I did with my monitor lizard) rather than just the charismatic skull.

Answers to frequently asked questions

No, I did not kill this otter.

No, I do not endorse the killing of otters.

No, I did not find it myself. It was found by a friend whose identity I will not disclose just in case I am mistaken about the legality of collecting roadkilled otters in the UK.

Yes, I respect the dignity of wild animals.

No, I don’t consider it more dignified for a carcass to rot by the side of a road than to be used for scientific purposes.

Yes, I am completely cool with my own body being used for science after I die.

 

Long-term readers will remember that way back in the pre-history of this blog, I wrote about my experience de-fleshing a pig head, which because the very first part in our ongoing series Things to Make and Do. In a subsequent post with a sheep-skull multiview, I included the multiview of that pig skull, too. Here it is:

Mike’s first pig skull, cranium only. Top row: dorsal view, anterior to right; middle row, from left to right: posterior, right lateral and anterior views; bottom row: ventral view, anterior to right.

As I noted in that sheep-skull post, I no longer own that skull: I donated it to be the first prize for the quiz in the very first TetZooCon, and it was won by Kelvin Britton.

But around the same time, our church hosted a barbecue even in which an entire pig was slow-roasted, and at the end of it I took the head home and prepped the skull out of it. The bone was much more fragile for having been roasted instead of simmered, and was in some danger of crumbling apart, but I stablised it with diluted PVA and it holds together OK.

Here it is:

Mike’s second pig skull, cranium and mandible in articulation. Top row: dorsal view, anterior to right; middle row, from left to right: posterior, left lateral (reversed) and anterior views; bottom row: ventral view, anterior to right.

Even allowing that the new skull was photographed with the mandible in place, the difference between the two is shocking. In particular, check out the dorsal views: the zygomatic arches of the first pig protrude way further laterally, and are much more robust than those of the second pig, and the whole shape of the skull roof is different.

I’m not sure what to make of this. I assume what we’re seeing here is variation of different breeds within the single domesticated species Sus domesticus, analogous to the way bulldog and greyhound skulls differer dramatically despite both being breeds of Canis familiaris. There are a lot of pig breeds out there, so perhaps it’s not too surprising. On the other hand, while the different dogs were bred for different purposes, I’d have thought all the pig were bred for the same purpose: to put on weight and provide meat. So I don’t know why such different skulls would have been selected for.

I wanted to do a three-way comparison between my carnivoran skulls, but I’m too impatient to wait till I’ve got the fox’s skull out of its head. So here are the two I have now: the badger (left) and the cat (right):

2016-04-01 14.34.39

(Both skulls appear with their first three cervicals.)

As you can see, the badger is more impressive in every way. It’s physically bigger of course, but also much more robust, as most easily seen in the zygomatic arches and the fully fused skull. Also relevant is the huge sagittal crest, which you will recall anchored hugely oversized jaw-muscles. In comparison, the cat’s jaw muscles were like those of pussy-cats.

It’s like the difference between a tyrannosaur and an allosaur.

You can see the crest more clearly — and general robustitude — in anterodorsolateral view:

2016-04-01 14.59.39

We really do underestimate what awesome animals badgers are. One of the many reasons I would never participate in a badger cull is simple, straightforward fear.

Do not meddle in the affairs of badgers, for they are unsubtle and quick to bite your arm off.

There’s no sense in decapitating a badger if you’re not going to make good use of the severed head. So here’s what I did with mine. First, a reminder of the state it was in after yesterday’s adventures:

2016-03-27 17.37.31

Ideally, I would have liked to skin the head — it would have made subsequent stages easier and less messy. But as I noted last time, badgers have very tough skin, and it was hard to do anything with it. I feared that the force necessary would at best damage the underlying bone, and at worst give me a nasty cut.

So I satisfied myself with trimming away the flesh collar, leaving the head-and-anterior-neck segment a little shorter, and of a suitable size to go into the saucepan:

2016-03-27 17.45.19

See?

2016-03-27 17.48.11

Then it was a simple matter of filling with hot water …

2016-03-27 17.48.57

… then bringing it all up to a simmer, and giving it a couple of hours while I played some Skyrim and watched an episode of Elementary. Once I’d drained the water off, here’s the result of the first simmer:

2016-03-27 20.22.53

As you can see (you may need to click through to make it out properly), that tough skin has contracted so hard that it’s pulled away from the skull at the top, exposing part of the distinctive midline crest.

Anyway, with the skin now softened it was relatively easy (though disgusting) to peel it off. Once all the rest of the superficial soft-tissue was gone, the massive massive muscles that attached to the midline crest were apparent.

2016-03-27 21.43.40

I broke these off:

2016-03-27 21.46.36

You can see one of them in the last photo. It really is a substantial piece of equipment: and you can see as well that the muscle mass going through the zygomatic arches is substantial.

You may also notice that at this stage, I’ve left the nose intact. That’s because I didn’t want to risk damaging the delicate nasal turbinates by pulling the soft-tissue away too roughly. Instead, I left it on for the second simmer:

2016-03-27 21.47.59

As you can see, it came out from that with the meat much more cooked, and so easier to remove:

2016-03-28 14.00.25

In my previous adventures preparing mammal skulls, I’ve found that one of the most satisfying moments is when the mandible (lower jaw) comes away from the cranium. You really feel that you’re making progress then, and it becomes much easier to reach some of the tricker areas of soft-tissue. That doesn’t happen with badgers: their jaws are permanently articulated, with cylindrical articular condyles wrapped in incomplete bone-tunnels. (I hope I can show you this properly once preparation is complete.)

Anyway, I was able to do a much better job of removing the meat this time: only scraps are left, and I was also at this point able to remove and begin cleaning the first few cervical vertebrae. I have the atlas, axis and damaged third. (I discarded the last of these, since it’s not complete.) Here’s the state of it at this point:

2016-03-28 14.09.34

And that skull in right lateral view, hopefully dispelling any remaining misconceptions you may have had about badgers being cute:

2016-03-28 14.09.49

As you can see, there were still plenty of scraps of hard-to-remove flesh clinging on, especially around the jaws and the base of the cranium. So it was time for simmer number three. I will spare you yet more photos of my saucepan, and instead skip straight to the skull as it appeared after this phase, and after I’d removed more of the flesh. Much nicer:

2016-03-28 16.11.01

You may be wondering, what is the best way to clean the teeth of a dead and partially prepared badger skull? Sometimes the obvious answer is the right one, and this is one of those occasions. A toothbrush is the tool of choice, and it works wonders with the base of the cranium, too. (Warning: do not allow the toothbrush to re-enter civilian society after this experience.)

Here we have the skull with the mandible open:

2016-03-28 16.11.10

Do not get bitten by a badger.

Skull in dorsal view:

2016-03-28 16.10.49

(I will prepare nicer, scientific-quality photographs in orthogonal views once preparation is complete — as I have done for other skulls.)

One of the many things that’s impressed me about this badger is how very much meat there was on its skull. I kept it, or most of it, and now you have the privilege of seeing the skull and its soft-tissue together:

2016-03-28 16.13.19

This is dramatically different from how we think of heads, or at least of how I do. I think this is because when we hear “skull”, we’ve been conditioned by years of Scooby Doo and Indiana Jones to think “human skull”. And I think that human heads much more closely match the profile of their skulls than those of badgers do theirs.

Of course this is just another way of saying that there is a lot more muscle on a badger skull, which is another way of saying that this is a seriously powerful animal. I know I keep making this point, but I think it’s a point well worth making. The world has had quite enough of this kind of thing (from here):

dg_OB10338_D06756_Lg

And its time that we all started to give badgers the credit they deserve. They are basically small bears with misleadingly endearing facial coloration.

(BTW., when I say that I kept the meat, I mean that I kept it until I’d taken that photo. Then I threw it away. I’ve not kept it permanently, I’m not a sicko. No, I’m not.)

I leave you with one of the less successful old music-hall jokes:

  • First man: I say, I say I say! What’s the best way to remove the brain from a dead and partially cooked badger skull?
  • Second man: Actually, there is no good way. The best I’ve found is to shove a chopstick through the foramen magnum, swirl it around to break up the tissue, then shake the bits out and repeatedly rinse.
  • First man: That’s disgusting.
  • Second man: I never said it wasn’t.

Here is the residue, in our sink:

2016-03-28 16.10.35

Fiona, if you’re reading this: I promise I will have this all nicely cleaned up before you return from your parents’ house with the boys.

(Did I mention that Fiona had taken the boys to her parents’ house? It’s not because of the dead badger. It’s just coincidence. I think.)

 

Over the last couple of weeks, I’ve been fortunate enough to acquire two medium-sized native mammals, both roadkill specimens in good conditions: a fox and a badger:

2016-03-27 15.09.09

But I’ve found from bitter experience that prepping out the entire skeleton of good-sized animals like these is a lot of dirty smelly work. So I decided to make things easier on myself by only prepping the skulls of these two.

Step one: remove the heads.

What follows is not pretty. Parental advisory: you should avoid this post if you feel a misguided sentimentality about the already-dead corpses of deceased animals.

I considered several approaches, as recommended by commenters on this blog and people on Twitter, but ended up taking the butcher’s approach — mostly because I have a good, sharp knife, but lack some of the tools needed for other approaches.

I took on the fox first. I cut through the skin surrounding its neck, and peeled it back far enough to reveal the neck musculature:

2016-03-27 15.10.55

From there, it was pretty easy to slice away the muscles down towards the vertebrae — but impossible to get right to the vertebrae themselves, because they’re surrounded by gloop including not only muscles, but ligaments, fascia and tendons:

2016-03-27 15.12.03

I’d hoped to be able to feel my way to an intervertebral joint, and ease it apart with the knife. But that turned out to be difficult. It was also going to need a lot of force, and I was worried that down in among all that gloop, I might slip and cut myself.

So I used our the axe we use for chopping firewood. It would have been terrible for dealing with the flesh, but it was fine for the bones:

2016-03-27 15.14.12

Then it was the same procedure for the badger. I started by cutting a ring around the skin of the neck and peeling back.

Straight away, it was obvious that the badger is a much more serious piece of kit than the fox. It’s not as long, but it’s heavier, and much more muscular, and it has way tougher skin. I don’t know if foxes and badgers ever fight, but if they do, my money is on the badger every time. It would bite much harder and its claws are epic, too. The only thing the fox would be better at is running away.

2016-03-27 15.16.27

Then, as with the fox, I sliced away the meat till I reached the bony core of the neck:

2016-03-27 15.17.43

And again, the axe finished the job. I was left with a pair of decapitated corpses:

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And, more importantly, a pair of heads:

2016-03-27 15.18.48

Also, some evidence of my activities in the bloodstained chopping block. I hope the neighbours don’t see this and leap to the wrong conclusion:

2016-03-27 15.22.33

What to do with the sadly unloved postcrania? I have no further use for them, so I decided to bury the bodies. I went down to the bottom of our garden, only to find all the sheep in the adjacent field coming over to see what I was doing:

2016-03-27 15.23.42

Best stay back, sheep! Or you could be next!

I dug a hole, which is a lot more work than it looks. Predictably, given that I am England during what passes for springtime, it suddenly stared hailing while I was digging. But eventually, I was done:

2016-03-27 17.27.03

In went the postcranial pair:

2016-03-27 17.27.38

And pretty soon, you’d never have known anything had happened here.

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Next time: exciting adventures with the badger head!

The pheasant comes apart

March 26, 2016

A couple of weeks ago, I was given a pheasant, which I reduced to science and food. When we last saw it, it was down to a skinned and partially defleshed head/neck and feet. It’s been through a couple of defleshing rounds since then, and today I was able to take it fully apart:

2016-03-26 12.31.09

At the moment, the bits are laid out on this plate, drying. Small amounts of soft-tissue remain (and more on the second foot), which may need the attentions of invertebrates to fully clean.

It pains me to admit, but even though I have kept the cervical vertebrae, for most people the skull will be the interesting part. Here it is in a little more detail, disarticulated into about ten units. The mandible is to the right of this image; the rostrum to the left of it, and the main cranial section to the left again:

2016-03-26 12.31.47

To the sides are the bones that laterally connect the rostrum to the braincase: zygomatics, quadrates and what have you. They are laid out roughly in the right positions, though the two quadrates may have been switched. Once everything is clean and dry, I’ll glue it back together, using my ostrich skull to help guide me.

The feet are trickier. Here’s the one I took apart:

 

2016-03-26 12.31.35

At the top of the photo, you see a mass of ossified tendons, which operated the toes from more proximal areas. This is how all bird feet work, and it’s such a great scheme that it seems weird everything doesn’t do it.

Below these, we have the tarsometatarsus to the right, and the four digits to the left. Each digit has its phalanges in the right order, but I don’t know what order the digits themselves should be in. To help me get that right, I pulled out of prepping the other foot down, hence its current semi-zombified state:

2016-03-26 12.31.23

I’m hoping it’s still intact enough to guide me as a reassemble the bones of the other foot. (Once that’s done, I may also take this one to completion, or I may decide that one pheasant foot is enough.)

Anyway, it’s nice to be progressing this specimen. Next, I need to figure out the best way to decapitate a medium-sized mammal (like a fox or badger) without damaging the skull, and using no special equipment.