Help me! How can I deflesh a tortoise?
March 22, 2016
I’ve been lucky enough to acquire another beautiful specimen. It arrived in a box (though not from Amazon, despite what the box itself might suggest):
What’s inside?
Can it be? It is!
Now I’ve wanted a tortoise for a long time, because they are (Darren will back me up here) the freakiest of all tetrapods. Their scapulae and coracoids have somehow migrated inside their rib-cages (which bear the shell), and their dorsal vertebrae are fused to the shell all along its upper midline. Just ridiculous. Look, this is what I’m talking about. Compare with the much saner approach that armadillos use to having a shell.
Here’s my baby in left anterodorsolateral view:
And in right posteodorsolateral:
Can anyone tell me what species I have here?
Here he is (or she?) upside down, in left posteroventolateral view.
Come to think of it, can anyone tell me the sex of my specimen?
Here he or she is in anterior view, looking very stern.
The problem is — and I can’t quite believe this never occurred to me until I had a tortoise of my own — how on earth do you deflesh such a creature? I have no idea (and obviously no experience). Any hints?
Making science and food out of a pheasant
March 9, 2016
I was relaxing on the Sunday afternoon before last, when there was a knock on the door. A couple of friends of mine had popped round with a plastic sack containing a fox and a pheasant that they’d found. (They rightly pointed out that it sounded like a pub.)
The fox is a treat for another day. Here’s the pheasant:
(Don’t judge me on the state of our kitchen floor — that’s not important right now.)
It was 86 cm long from beak to tip of the tail-feathers, and massed 1393 g. The wingspan was hard to measure, because the wings want to pull back in towards the torso, but my best estimate is 73 cm.
Here’s the right wing extended:
Shamefully, I’ve not really played with a dead bird before, so it was a new experience for me to feel how astonishingly unmuscled the wings are. There’s nothing there but skin, bone and feathers. The wings are of course operated by tendons, which are powered by the massive breast muscles — something that shouldn’t be surprising since (A) it makes mechanical sense to concentrate the muscles near the centre of mass, and (B) everyone knows birds do this with their hindlimbs, hence the ridiculously thin legs of flamingoes.
I had planned to do a Brodkorb (1955) on the pheasant: plucking it and weighing the feathers; then skinning it and weighing the skin; then eviscerating it and weighing the viscera; and so on. turns out that this is a lot harder than it sounds. I physically couldn’t pull the feathers out of the wings, for example. After a not-very-long struggle, I gave up and pulled off the skin and feathers together.
Here’s the nude bird, looking like a dinosaur. (Who’d have guessed?)
Note the very distinctive and knobbly fatty deposits.
At this stage, since my Brodkorb-style teardown was a bust, I thought we might as well eat the parts of the pheasant that I didn’t want for science. So I trimmed off the breasts — you really get a sense of how massive the flight muscles are when you do this for a bird that started out intact — and the legs:
These fried up nicely — though they were hard to photograph through the steam:
The breasts were very tasty, more like pork than chicken in both flavour and texture. The legs were much tougher to deal with — it was hard to get the meat off them. Still a good flavour, though.
I’d removed the head-and-neck assembly, and the feet, for science. With that done, I thought I’d simmer the rest of the carcass for stock, but once that process had been under way for quarter of an hour or so, I had to admit that it was smelling of poo. I assume I’d not removed the guts sufficiently. I admitted defeat and tossed the carcass in the trash.
Then I gently simmered the head/neck and feet for an hour or two. Here’s how they looked (and check out how the yellow fat deposits have congealed into nodules):
What’s that? You want a close-up? Sure!
And one of the feet?
Those spurs are nasty!
Anyway, I picked off what flesh I could from the head/neck, and peeled away the scaly skin from the legs and some of the toes:
I’ve not peeled all the toes, because once that’s done only cartilage keeps the phalanges articulated, and that will come away with more simmering, leaving me with a jigsaw puzzle. The plan now is to keep one of the feet in its relatively intact state and skeletonise the other. Then I can use the whole one as a key to reassemble the bones of the other.
The skull, of course, I will continue to deflesh. More simmering will be needed before I can proceed. After a couple more iterations, I’ll put the skull out under a cage for invertebrates to clean up the remaining shreds of soft-tissue, before rinsing, cleaning, degreasing and drying.
Further bulletins as events warrant.
References
- Brodkorb, Pierce (1955). Number of feathers and weight of various systems in a Bald Eagle. The Wilson Bulletin 67(2):142.
What’s in Mike’s freezer?
February 26, 2016
What’s that in Mike’s freezer? Let’s take it out and have a look.
Onto the table out in the garden …
Unwrap another layer …
Hang on! That looks like … It can’t be, can it?
It is! It’s a buzzard!
A buzzard with extremely serious claws!
And a serious beak as well!
Further bulletins down the line, when I get a chance to play with it properly.
(Title stolen shamelessly from John Hutchinson’s blog.)
Things to Make and Do, part 18: jar of wasps
November 3, 2015
Here’s the jar of wasps sitting out on the table in our back garden:
OK, this is not so much an interesting specimen as a handy hint.
We hosted a picnic during the summer and it was absolutely infested with wasps. (One person was stung — everyone else had to look super-carefully at their sandwiches before each bite.) That made me realise we needed to get rid of all the wasps that haunt the garden, and this trap is the solution.
It could hardly be simpler: it’s an old jar with a tablespoon of jam in the bottom, topped up to half way with water. Then a tinfoil lid with a small hole poked through it with a teaspoon handle.
For some reason, wasps just can’t resist it: they crawl in, then drown themselves in the water trying to get to the jam. Then more wasps come. And they just keep coming, as you can see in the photo. We’re going to have to dig the wasps out and throw them away so that the trap has enough space for more.
The great thing about this is that it only seems to catch wasps: not bees, which simply don’t seem to see the appeal in jam-water.
My cat’s neck skeleton (first five cervicals)
October 27, 2015
When I separated my cat’s head from its body, the first five cervical vertebrae came with it. Never one to waste perfectly good cervicals, I prepped them as well as the skull. Here they are, nicely articulated. (Click through for high resolution.) Dorsal view at the top, then right lateral (actually, slightly dorsolateral) and ventral view at the bottom.
Or you may prefer the same image on a black background:
For those of us used to sauropod necks, where the atlas (C1) is a tiny, fragile ring, mammal atlases look bizarre, with their grotesque over-engineering and gigantic wings.
What is my mystery baby bird?
September 23, 2015
Here’s my newest specimen: a tiny baby bird, maybe 5 or 6 cm from wingtip to foot. This one came from my next-door neighbours: apparently it had been sitting on their car for several weeks before they thought to lift it off and give it to me.
As you can see, the specimen is extraordinarily well preserved — more or less mummified, I suppose by wind-drying. Like a Chinese duck, though less appetising.
Here is the slightly flattened left side:
So I have two questions:
- What is this? Beyond the level of “a bird of some kind”.
- How can I prep it down to just a tiny skeleton? The only idea I have, really, is to slightly moisten it, and leave it in a tub with a hole in the top for inverts to get in. Can I do better?
Help me!
Here’s that cat-skull multiview you ordered
September 22, 2015
The process of reassembling my cat skull continues. I now have the sphenoid and both nasals now back in place, and the time has come for the now-traditional multiview. (Previous examples: pig skull, wallaby skull, sheep skull.
Click through for seriously high resolution (9602 × 7642).
And here it is on a black background:
As though you need to be told: the top row shows the dorsal view, the middle row (from left to right) shows posterior, right lateral and anterior views, and the bottom row shows the ventral view.
Enjoy!
The Internet is for cat photos. Here are mine.
September 17, 2015
Regular readers will remember that I recently fished my cat skull out of the tub where invertebrates had been hard at work defleshing it, and put it to soak — first in soapy water, then in clean water, and finally in dilute hydrogen peroxide. It was in a pretty terrible state, having either been smashed by a car, or damaged by my rather unsophisticated process of removing the head from the torso. Here’s a reminder:
After bleaching in H2O2, the skull parts looked much better, but were still very delicate. Here is the main portion of the cranium, missing the braincase and the right upper jaw, upside down, in right posteroventral view.
Putting it back together was difficult. I am using regular water-soluble wood glue, largely so that if I make a mistake I can just soak the wrongly-joined bits apart and try again.
I started by gluing the braincase (at the top of the plate in the first picture) onto the back of the main cranium piece. Unfortunately, as you’ll see below, I wasn’t able to get a very clean join — I can only assume that one or other part was slightly distorted by whatever force broke the skull apart. Still, having done that, I had a better platform to reattach the right upper jaw (lower left of the plate). I was then able to reattach the broken-off part of the right zygomatic arch (at about 4 o’clock on the plate, just to the right of the lower of the two dentaries, and below a vertebra). It didn’t fit quite right, but what can you do? FInally, I was able to reattach another small piece — at 6:30 pm on the plate — which I think is part of the left auditory bulla.
That gave me a workable cranium (though I have some bits left over — see below.) It was time to repair the right dentary. Its articular cylinder (not really a condyle, despite its name) had somehow got blasted off, as had its retroarticular process: it was quite satisfying to figure out how those Shards Of Mediocrity fitted onto the main part of the dentary.
With that done, I had to glue together the two dentaries. That’s hard to do: it’s awkward to brace them in position for the glue to set, and difficult to get the angle between the two bones correct so that the two articular cylinders both sit neatly in their receptacles in the cranium. Here’s the solution I came up with:
I rested the cranium upside down, covered the jaw with some thin, pliant plastic (actually a sandwich bag) and used the cranium itself as a perfectly proportioned brace to hold the dentaries in place. Then I was able to glue them more or less correctly, and to reinforce the joint with more glue once the first lot had set.
I’ve still not got it quite right — the mandibular symphysis is wonky — but I think it will do. And if I change my mind, I can always soak the mandible apart and try again.
(As a matter of fact, I’d already done that once, having initially glued the dentaries together at the wrong angle, so that the assembled mandible was too narrow, and wouldn’t articulate properly with the cranium.)
So now I have a pretty good mandible and cranium, as well as the first five cervical vertebrae (all but one of the postzygs of C5, which was lost in the head-removal process.) Here is the whole thing, put together, in dorsal view:
(You can see where the left zygomatic arch is damaged: the bones are not articulating correctly, as they do on the right.)
And here is the same assembly in left dorsolateral view:
And finally, the skull in anterodorsal view:
Note that the left canine is truncated. I am completely certain that this, at least, is not my doing, and must be damage that was done in life. Note, too, how the mandible is visibly wonky from this angle. Hmm. Maybe I will reset it again.
At the end of this process, I have a pretty nice cat skull. Unfortunately, I have seven shards left over, none of them more than about fifteen millimeters long. Here they are:
I’d welcome any help in figuring out what these bits are, and where on the skull they should be reattached. I don’t want to just throw them away. Click through for much higher resolution to get a better idea of what’s what. The top right piece is such a weird shape that someone must know what it is. The two peices at bottom right seem to be pairs, but I don’t know what they are a pair of. The rest? No idea.
I leave you with the dorsal view again, but this time in glorious 3D for those of you who have been wise enough to get some red-cyan 3D glasses. (Seriously folks, they’re like fifty cents a pair. Just get some. You won’t regret it.)
Some time soon: those first five cervicals in more detail.
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:
And here is a closeup of a mandible (slightly foreshortened):
“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 optimistic that I can still wind up with a pretty good cat skull.
My early Christmas present: a dead corn snake
December 18, 2014
A friend’s daughter owned a pet corn snake, and a hamster. About a month ago, the former got into the latter’s cage — and in a reversal of the usual course of such events, sustained some nasty injuries. As snakes often do, it struggled to recover, and the wound seems to have necrotised.
This morning I got an email from the friend saying that the snake had died, and asking whether I would like it. I managed to restrain my enthusiasm for long enough to express condolences to the daughter; and an hour later, the snake was delivered!
Here it is — as with all these images, click through for the full resolution. I’ve learned that it’s difficult to measure the length of a snake — they don’t lay out straight in the way that you’d like, even when they’re dead — but as best I can make out, it’s 120 cm long. It weighs 225 g, but don’t tell Fiona I used the kitchen scales.
The hamster wound is very apparent, just behind the neck, on the left hand side. Here’s the head and neck in close-up:
Ouch — very nasty. It can’t have been pleasant watching a pet linger on with a wound like that.
He (or she? How do you sex a snake?) was a handsome beast, too. Here’s the head. You can easily make out the individual large scales covering it, and make out some of the shape of the skull.
The skulls of snakes are beyond weird. Here is one from an unspecified non-venomous snake at Skulls Unlimited (i.e. probably not a corn snake):
Hopefully at some point I’ll be able to show you my own snake’s skull. In the mean time, this guy says he has a corn-snake skull, but the photography’s not very good.
Finally, here is my snake, mouth open, showing the pterygoid teeth on the roof of the mouth:
What next? It seems clear that bugging is the only realistic way to free up the skeleton, and this may be the specimen that persuades me to invest in a proper colony of dermestids rather than just relying on whatever inverts happen to wander past.
It might be worth trying to skin and gut the snake first. Gutting will be easy; skinning might be very difficult. I think that removing the skin from the skull without damaging the very delicate bones might be impossible. Can dermestids cope with snake skin?
I’m taking advice!
Sauropod Vertebra Picture of the Week 
