Things to Make and Do, Part 16: cat skull

September 11, 2015

Just under a year ago, the children across the road, who know I’m interested in comparative anatomy, told me that they’d found a dead cat by the side of the road, and asked whether I wanted it. Silly question, of course I did!

I’ve learned from bitter experience that prepping the whole skeleton out of an animal is a very time-consuming process — so time-consuming that I usually just don’t get around to it. This time, I thought I’d just do the skull. So I removed the head (not a pleasant process) and discarded the body.

I did the usual sequence of simmerings with the head, peeling off the skin and fur, then removing muscle, till I was down to just bone, gristle, and the hard-to-remove bits of soft tissue that always adhere in one place or another. At that point, I left the bones in a plastic tub in the woodshed, with a couple of holes in the lid so that invertebrates could get in and deal with the remaining gloop.

Yesterday I had a look (and a smell), and it seems all the soft-tissue is gone, thanks to the hard work of the tiny collaborators who never make it into the acknowledgements. So I soaked the skull pieces in soapy water for a day. Then today, I rinsed them off and left them to soak in pure water for a few hours. Finally, I changed the water, and added some H2O2 to degrease the bones. They are now foaming away merrily. Tomorrow I’ll take them out, rinse them off one more time, dry them, and see what state they’re in.

Here’s how they look today, after rinsing:

IMG_1977

And here is a closeup of a mandible (slightly foreshortened):

IMG_1977-closeup

“But Mike”, you ask, “Why is it in so many pieces?”

I actually don’t know. As I was taking the head apart, it seemed to be whole, but as it got down to the raw bone, it was apparent that the skull was very badly damaged. In the picture above, the main part of the cranium is upside down, half way down the left hand side. Below it is the rest of the cranium, the left side of the upper jaw. Above that is the back of the cranium, most of the braincase. The whole thing just came apart into three pieces — and not along sutures. This is breakage.

I’m not sure how it happened. At first, I thought it must be how the cat died — maybe struck a glancing blow by a car. But I increasingly wonder whether I stupidly did this myself in the process of removing the head from the torso. (I did not use a scalpel.)

Anyway, we’ll see how well the pieces can be reassembled once they have dried out. I’m optimised that I can still wind up with a pretty good cat skull.

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8 Responses to “Things to Make and Do, Part 16: cat skull”

  1. Frosted Flake Says:

    Interesting to compare fresh bone to a fossil.

    By coincidence, I have a small scar at the middle joint of both of my thumbs. Cat bites. A great time to demand antibiotics. A cat bite often becomes infected.

    Bit of advice. When breaking up a cat fight, have in mind where you are going to toss the cat before you grab him. Grabbing the scruff of the neck will not prevent him turning and getting you.

    Grab, chuck. One fluid motion. Don’t give him time to bite you. Or he will.

  2. Newt Says:

    Looking good! I imagine your first thought, of automobile damage, is the correct one. Mammal skulls, especially in situ are pretty sturdy; you’d have known if you broke it.

    My first attempt at preparing a skeleton – a road-killed fox squirrel – ended after I’d laboriously skinned the thing only to find the skull was cracked to bits. (I was greedy and wanted to save skin and bones; it’s much easier to just go with one or the other).

  3. derek Says:

    Now it all comes out. We hear how skulls and teeth are so much more common that the whole rest of the body is lumped together as “post cranial”.

    Paleontologists say “Millions of years, you know, it’s so rare the skeleton survives”. Now we know the truth: they just can’t be bothered.

  4. Mike Taylor Says:

    … the irony, of course, being that here at SV-POW! we don’t really like heads much, and greatly prefer vertebrae. In fact, I have been known to refer to the skull as the pre-postcranium, relegating it to the unimportant position it deserves.

  5. Mike Taylor Says:

    I imagine your first thought, of automobile damage, is the correct one. Mammal skulls, especially in situ are pretty sturdy; you’d have known if you broke it.

    I hope you’re right (and this it’s therefore not my fault) — but I’d have expected to see some visible external damage if it was hit hard enough to do this to the skull.


  6. The head of that squirrel I mentioned looked fine externally, but was a mess of cranial shards inside; I see now I didn’t explain that properly. The soft tissue maintained the shape despite the skull damage.

  7. John Scanlon Says:

    Adult cat skulls are very tough and compact, I really don’t think it would be possible to break a fresh one by hand without hurting yourself (probably on the teeth). Vehicle impact much more likely.


  8. […] readers will remember that I recently fished my cat skull out of the tub where invertebrates had been hard at work defleshing i…, and put it to soak — first in soapy water, then in clean water, and finally in dilute […]


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