Things to Make and Do, part 3: Butchering a Wallaby

November 3, 2009

This is part 3 of an emerging and occasional SV-POW! series: part 1 was the pig skull, and part 2 was the lizard feet (though not advertised as such because I couldn’t resist the sauropod pun).

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Bennett's wallaby, right lateral view

Today, we’re going to be taking a wallaby apart.  Specifically, a Bennett’s wallaby, the larger of the two subspecies of the red-necked wallaby Macropus rufogriseus.  I was delighted (though of course also saddened) to get a call on Saturday afternoon from the very same mini-zoo that had given me Charlie the monitor — Dick Whittington Farm Park in Longhope, Gloucestershire.  They have a small group of seven wallabies sharing a paddock with goats, and one had died — most likely from being butted by one of the goats, although there were no external signs of injury.

This is going to be the largest animal I’ve prepared the skeleton out of — I measured it at 123 cm from snout to tail and 10.5 kg total weight, which compares with 75 cm and 12 kg for the badger, 100 cm and 5.2 kg for the fox and 111 cm and 3.4 kg for the monitor.  Yes, the badger was heavier, but the awkward shape of the wallaby makes it all-round “bigger” and harder to deal with.  Both the badger and the fox would, just, fit into large plastic toy-boxes which I buried and will exhume after a suitable time has passed, but that wasn’t going to work for the wallaby.  I needed to take that baby apart:

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Bennett's wallaby, right ventrolateral view into guts

I was pleasantly surprised at what good condition the guts were in (compared with the horrible state of Charlie innards) — nice and fresh.  If I’d had time, I’d have attempted to learn something from a proper dissection, but as I was pushed for time (trying to get this done in my lunch break) I had to push on.  I discarded the guts and started to carve up the remainder.

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Bennett's wallaby in posteroventral view. right leg removed; Homo sapiens for scale

The knife is a Norwegian fisherman’s knife — very sharp, and short enough to be easy to wield.  It’s perfect for dismembering a carcass this size, even though previously I’ve only used it for slicing sushi rolls.  It was a Christmas present from my employer, Index Data, a few years ago.

My plan was to carefully divide the animal into seven portions (head, torso, tail and four legs), remove as much skin and muscle as I could without risking damage to the bone, and to process the parts separately.

DSCN7345

Bennett's wallaby, in kit form, mostly dorsal view but with the head and torso in left lateral. WARNING: GRAPHIC CONTENT

After some thought, I decided to prepare the skull and the left fore- and hind-limb by boiling, and to bury the rest in the box.  Here are the relevant divisions:

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Bennet's wallaby not looking at all healthy. Top: torso, tail and right fore- and hindlimbs, awaiting burial. Bottom left: head, left fore- and hindlimbs, awaiting cooking. Bottom right: bag full of discarded soft-tissue

Then I put the pot through an hour’s simmering, peeled the skin off the skull and feet, and removed what meat I could; then I simmered a second time and removed more meat.  By this stage, I was able to remove the three most anterior cervicals, which had been attached to the back of the skull — but they are still so covered with attached flesh that they’re not much use yet.  Here’s how the simmered material is looking:

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Bennett's wallaby: skull, anterior cervical vertebrae and left hind-limb long bones

And here is the skull as it looks now, after a little more flesh-picking (but not nearly enough):

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Bennett's wallaby, partially prepared skull in right lateral view

I think that it (and the other boiled bones pictures above) would benefit from a third simmer-and-pick session before I put them out somewhere for invertebrates to deal with.  While that’s going on, I’ll prep out the foot and the forelimb, which have also been boiled twice but phalanges are a right nasty piece of work.

And then I have to decide what to do with my big yellow box that has the rest of the bits in.  Plan A is still burying, but it is kind of tempting to simmer these parts, too, and get the whole thing completed much more quickly.

On the other hand, now is not a good time for such an effort: I will be away from home all week on a mission of utmost importance, and of great relevance to this blog.  Details to follow!

Finally, I leave you with your weekly sauropod-vertebra goodness!

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Giraffatitan brancai paralectotype HMN SI, cervical vertebrae 2 and 3 in right lateral view, attempting to do DinoMorph

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32 Responses to “Things to Make and Do, part 3: Butchering a Wallaby”

  1. Zach Miller Says:

    Wonderful dissection! I always forget about those tusk-shaped lower incisors on walabies and kangaroos. What are they used for? Seems like they’re at a bad angle for nipping vegetation…

  2. Allen Hazen Says:

    Thank you for that! Makes me embarrassed for not being more enterprising when I find corpses.

    General mammalian osteology question. There seems to be a pointy downward projection from the zygomatic arch, near the front. How common a feature is this in mammals? Is there an obvious reason for it (having to do with some ligament attachment?)? Assuming functions are known in both cases, is this doing the same thing as the huge downward projection from the zygoma in Glyptodon?

    (Apologies for asking mammalian questions on a Sauropod site!)


  3. very neat process.

    too bad you can’t get access to any flesh eating beetles (i’m a big fan of the TV show bones, and they use them every couple episodes) they would make the later clean up easier i would imagine.

    are you going to be mounting this guy like the monitor lizard? (which i’m excited to see how it turns out!)

    on a sidenote the sauropod gallery of palaeo reconstructions is up on ART Evolved http://blogevolved.blogspot.com/2009/11/sauropod-gallery.html.

    i humbly implore you once again oh great gurus of sauropodom to maybe give it a slight mention on your infamous site.

    also if any of the pictures catch your eye for what ever reason, i’m sure none of our artists would object to, you using them here for a SV-POW review and/or analysis! as most of the contributors are aspiring palaeo-artists i’m sure they’d be very keen to learn what real scientists such as yourself think or their reconstructions (good and bad).

    thank you for your time

  4. Matt Wedel Says:

    My guess is that the downward projection on the zygomatic arch is associated with the attachment of the masseter muscle, one of the primary jaw-closers. I don’t know what’s up with the giant droopy projection in sloths. Hopefully Darren will chime in and sort us out.

    Mike does have access to carrion beetles, the plastic cans of decomposing critters in his woodshed are full of them. If you want dermestids like those used on CSI, etc, all you have to do is visit some roadkill. They’re everywhere.

    And no worries, I already have a plan to cover the sauropod edition of Art Evolved next week, once all the submissions are in. Thanks for the heads up, though.

  5. Mike Taylor Says:

    To be precise, I don’t (as far as I know) have dermestids, the classic carrion beetles. Instead, for my small animals, I’ve been using Darren’s “body in a box” method, which is just like it says — I put the body in a box which has small holes to let insects in and out, and leave it in the woodshed to ensure it can’t get flooded with rain. Some kind of insect gets in, lays eggs, flies away; and the eggs hatch into grubs that clean up my specimens before (in an ideal world) pupating, emerging and flying away, but (more often) drown because rain actually does get in after all. Drowned insect larvae notwithstanding, I did get excellent results from using this method on my baby rabbit (which I guess will be a future T2M&D post), and I have other small animals continuing to cook in this way. But it would be a non-starter for the big guys.

  6. Zach Miller Says:

    There’s a giant ventrally-projecting prong on the zygomatic arches of glyptodonts. I’ve often wondered how the skull musculature on those beasts worked.

  7. martyndarkly Says:

    Very nice work mate. It reminds me of early episodes of Get Stuffed.

    ‘First, we have to wash our hands….’

  8. Matt Wedel Says:

    To be precise, I don’t (as far as I know) have dermestids, the classic carrion beetles.

    Yeah, you do. You’re not keeping a captive colony, but who do you think is getting in through the holes in the tubs and eating your critters?

    Folks, dermestids were not invented by the AMNH or FBI, and they’re not rare or exotic. They’re distributed worldwide and they show up wherever there is dead stuff to eat. Keeping a captive colony allows for faster and more controlled beetle-prepping, but in terms of mechanism it is no different from putting your dead critters in perforated tubs in the woodshed.

  9. Mike Taylor Says:

    To be precise, I don’t (as far as I know) have dermestids, the classic carrion beetles.

    Yeah, you do. You’re not keeping a captive colony, but who do you think is getting in through the holes in the tubs and eating your critters?

    Could be anyone. Surely you’re not saying that dermestids are the only little critters that like a free meal?

  10. 220mya Says:

    And, if for some reason you don’t want to attract wild dermestids, its pretty easy to purchase your own starter colony. For example, here:

    http://wardsci.com/product.asp_Q_pn_E_IG0011612_A_Dermestid+Beetle+Assortment+Living+Specimen

  11. Jaime A. Headden Says:

    The descending zygomatic process of sloths is a portion of the origin in the superficial masseter. This is how it is in living tree sloths (Bradypus) at least. Glean Naples (1985; here) for more. Increase in the origin of the masseteric system is probably related to the presence of a shear bite in both sloths (teeth are occluded directly vertically, and the anterior teeth slide against one another vertically). The same functional bite system has been alluded to some ceratopsians due to similar configuration of the dentition, to bring this into a more familiar paleontological ground. All sloths and glyptodonts are members of Edentata, and share the same form of the zygomatic. Unlike sloths, glyptodonts lack a clear shearing bite, which may preclude the argument suggested above.

  12. Jaime A. Headden Says:

    I seem to have erred on my parsing….

  13. David Marjanović Says:

    trying to get this done in my lunch break

    I’m speechless.

    presence of a shear bite in both sloths (teeth are occluded directly vertically, and the anterior teeth slide against one another vertically)

    Hey cool.

  14. Matt Wedel Says:

    Could be anyone. Surely you’re not saying that dermestids are the only little critters that like a free meal?

    Whatever gave you that idea? Of course dermestids aren’t the only ones that will chew on dead stuff, and I never said that they were. But they are the most common eaters of carcasses, and they are distributed worldwide. They are also definitely present in your tubs in the woodshed. I recognized them when I was there a couple of months ago. At the time, I didn’t jump up and down and yell, “There’s a dermestid, there’s a dermestid!” but if I’d known that the presence or absence of dermestids in your shed would turn into a big federal case, I would have. Remind me to point them out to you next time.

    Better yet, post us some pictures of the little critters that are still cooking in their tubs, and I’ll mark ‘em up.

  15. Nathan Myers Says:

    What is this, Stinkin’ Bugs Newsletter?

    Let us forthhence accept dermestids, like geese, like pterosaurs, like giraffes, as honorary sauropods.

  16. Graham King Says:

    Aw, poor lil’ wallaby; but fascinating info, Mike!

    Did you see anything to confirm goat-butt, I mean butting by a goat, as cause-of-death (busted ribs, internal bleeding)? I’m surprised a wallaby wouldn’t get out of the way of a butt-happy goat; though maybe the butt was sudden and without warning.

    Those lower-jaw-tips (teeth) are extraordinary to see; I’d never realized they were that way before.

    I also have a song of my own about wallabies; but I won’t sing it here and now. I can tell you, though, that ‘wallaby’ is the most-used word in the song..
    (I love that word, don’t you?)
    ..followed closely by ‘boing’.

  17. Jonathan Cramb Says:

    It looks like your wallaby is a sub-adult; the fourth molar hasn’t erupted.

    In response to Zach Miller’s initial question:

    The larger lower first incisor is indeed used for nipping vegetation, although other diprotodont marsupials use it for digging into wood (petaurids), stabbing prey (petaurids again, thylacoleonids) and possibly intraspecific combat (some diprotodontids).

  18. Nathan Myers Says:

    I’m sitting here admiring the grease spots on the butcher-paper backing around the femur.

  19. Mike Taylor Says:

    Nathan, that is common-or-garden A4 printer paper!

    Jonathan, thanks for the hint on the age. Apparently (I got this from Darren) male Bennett’s wallabies are mature at 20-24 months. Since mine died at 18 months, sub-adult makes sense.

    Graham, no, I’ve seen no signs of cause of death; but then I wasn’t looking closely, just trying to get the skeleton out quickly and cleanly.

    I admit I have found myself humming Tie Me Kangaroo Down, Sport rather too much as I’ve been cleaning this specimen!


  20. [...] 6, 2009 I’m following up immediately on my last post because I am having so much fun with my wallaby carcass.  As you’ll recall, I was lucky [...]

  21. Allen Hazen Says:

    Thanks, Zach and Jaime! (Glyptodon skulls are among the weirder pieces of mammalian anatomy…)
    –Mike Taylor-
    Leigh Van Valen (in an article with a footnote thanking his cat for providing experimental mouse and small bird carcasses) suggested that, at least for small animals, Woodlice (=Pillbugs, =Slaters: I remember him mentioning the genus Armadillidium in particular) were better for skeletonizing than dermestids. My guess is, that with a garden in a temperate climate, you’ve got some of them, too.

  22. Mike Taylor Says:

    Hi, Allen. Yes, we have woodlice and plenty of them. I think they were the prime movers in getting the pig skull cleaned up.

  23. Graham King Says:

    Oh neat! I didn’t realize woodlice would do that.
    There are probably some living in or on a wall nearby..

  24. William Miller Says:

    Interesting, I always thought woodlice were herbivores. Guess you learn something every day…

    (That kind of woodlice does eat plants, too, right? Or is this a different kind of woodlouse than the ordinary ‘pillbug’?)


  25. [...] 2, 2010 It’s been a while since we last caught up with my wallaby, which I am suddenly going to decide to call Logan.  When we saw him last, I was concentrating on [...]

  26. John Park Says:

    wow absolutely amazing process, thanks for sharing.

  27. Nick Gardner Says:

    A bit of advice. The prices on most biological supply companies for dermestids are way overpriced. Browse around on taxidermy forums or eBay. They’re priced slightly better (e.g. more beetles per $$$) there usually, especially if you buy from people in taxidermy forums and the like (eBay’s usually not so great, but it’s a more fair deal than Ward’s). But starting off with a colony of 50 beetles (the smallish amounts offered in the Ward’s kit) will take forever to get you anywhere.

    I’m colony sitting for a friend and there’s virtually no smell at all (they’re in my bathroom)…


  28. [...] referred to our old buddy HMN SII as the paralectotype specimen of Giraffatitan brancai.  (Butchering a wallaby, photographing big bones, How fat was Camarasaurus, and baby giraffe neck, in case you were [...]

  29. Treefrog Says:

    You should have eaten at least the haunches: delicious sweet meat. We used to shoot and eat Bennet’s wallabies when I lived in Tasmania: they are rabbit-common down there.
    Isn’t Bennett’s the race which got loose in the Loch Lomond area years back and still live up there? The UK’s only marsupial.

  30. Mike Taylor Says:

    Yes, I believe there are multiple feral populations of Bennet’s wallaby in the UK. I’ve never seen them, though.


  31. [...] These exist in most reptiles, but have been lost in most mammals. (They do exist in wallabies, but they are a very different shape.) Developmentally the chevrons mirror the neural arch, and [...]


  32. [...] is indeed Logan the wallaby from waaay back in late 2009. Here’s how I butchered him, and some detail on his feet, and how his skull  turned out. Back then I prepped out a forelimb [...]


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