Skull audit: Wedel responds
February 9, 2022
Left to right: alligator, beaver, black bear, armadillo, cat, ostrich. I know, the archosaurs aren’t mammals, and the alligator isn’t even a skull. But if you can’t have a lounge lizard crash your mammal skull party, what are you even doing with your life? Not pictured: about four rabbit skulls I forgot I had boxed up, plus a couple of turtles (yeah, yeah) sitting on a friend’s desk, in their locked office.
It warmed my crooked little heart to see Mike Taylor, noted sauropodologist and disdainer-of-mammal-heads, return mammal skulls to the blog’s front page yesterday. Naturally I had to support my friend and colleague in this difficult time, when he may be experiencing confusing feelings regarding nasal turbinates, multi-cusped teeth, and the dentary-squamosal jaw joint.
My skull collection is split across home and office, but I had to go in to campus this afternoon for a video recording thing, so I got most of the office set, shown above, on that jaunt.
After the workday ended, I had just enough time before the light faded to assemble and photograph the home collection:
Back row: peccary, pig, deer, sheep, dog. Middle row: opossum, rabbit. Front row: opossum, marten (both hemisected). Not pictured: emergency backup sheep, moar rabbits
I’ve blogged about the bear, the pig, and the hemisected skulls, but I think that’s it. I should do more skull blogging, most of these have a story:
- I prepped the armadillo, cat, rabbit, and sheep skulls myself (besides the bear and pig). The first two I found in the woods, the mostly-decomposed rabbit was a gift from my father-in-law, and the sheep head I obtained from the market down the street ($10, and I ate the meat).
- The alligator head and deer skull were gifts, from Vicki and from my brother Ryan, respectively.
- The rest I purchased here and there over the years, usually when they were on deep discount. The peccary is a memento of a trip to Big Bend back in 2007 (I bought it at a taxidermy shop a long way outside the national park), and the dog came from the seconds bin at the Museum of Osteology — I plan to saw off the top of the braincase to see the cranial nerve exits, just as in the preparation by Peter Dodson shown in this post.
I have more heads awaiting skull-ization in various freezers, too. Couple more pig heads at work, and at the house a strategic reserve sheep head, plus skunk, squirrel, and rat. Plus a partially-mummified but mostly defleshed armadillo whose saga deserves a detailed recounting:
NB: the stray bits toward the bottom of the image are from a cat. Mr. Armadillo’s limb bones and vertebrae are still in the armadillo kit.
In the first comment on Mike’s post yesterday, I expressed envy that he had the better skull collection. After pulling together all my critters, I think I just have a worse memory. In my defense, it’s been almost two years since I was in the office regularly, and about half the skulls in the home collection are recent-ish acquistions (~last three years), so a lot of stuff had either fallen out of memory or not gotten properly established yet. But Mike has definitely prepped more — and more exotic — skeletons, and it was his enthusiastic collecting and blogging of dead animal bits that inspired me to start my recent-ish spate of skull preparations. More to come on that front as time and opportunity allow, probably starting with this:
Partial audit of mammal skulls
February 8, 2022
These are out as I consider how to reorganise my office.
The pig skull came from a hog-roast, and was very crumbly by the time I had prepped it out. It’s subsequently had an accident when it fell off a loudspeaker in my youngest son’s room, so it’s not the pig it once was. (I have a plate of pig-skull shards that I know full well I will never reassemble, but can’t quite bring myself to toss out). The sheep is of course a ram, the horns being the giveaway: shame the right horn is broken off at mid-length. The deer awaits reassembly.
I think all the carnivorans have featured here previously, with the possible exception of the emergency backup badger which I opportunistically harvested from a rotting roadkill about a year ago.
We’ve seen the wallaby and squirrel here, too. I think the rabbit has yet to put in an appearance, but we have more than enough rabbit stuff on this here sauropod blog so I’m not going to lose sleep over that.
Other mammals available to me: I have a rat, a hamster and a gerbil in various states of decay in plastic tubs in the woodshed. Come summer (since this is definitely an outdoor sport) I might see what can be done to get the skulls out of those. You will excuse me if I don’t go out of my way to extract a gerbil postcranium.
Bone cancer in a Triassic stem turtle
February 7, 2019
Cool new paper out today by Yara Haridy and colleagues, describing the oldest known osteosarcoma in the vertebrate fossil record. The growth in question is on the proximal femur of the Triassic stem turtle Pappochelys.
Brian Engh did his usual amazing job illustrating this pervert turtle with no shell and a weird growth on its butt.
I don’t have a ton more to say about the paper, it’s short and sweet. I got to meet Yara in person at SVP last fall and learn about her research, and there is going to a LOT more weird stuff coming down the pike. She is after some really fundamental questions about where bone comes from, how it develops in the first place, and how it remodels and heals. Get ready to see some crazy jacked-up bones from other basal amniotes in the next few years, including some vertebrae that are so horked that Yara and I spent some time discussing which end was which.
On a probably inevitable and purely selfish personal note, I don’t blog nearly enough about turtles. I like turtles. Which, if you’re going to say, you gotta say like this kid:
In fact, I love turtles, and if there were no sauropods, I’d probably be working on turtles. Other people show you pictures of their cats, I’m going to show you pictures of my turtle, Easty. She’s a female three-toed box turtle, Terrapene carolina triunguis.
Here she is closing in on an unlucky roly-poly (or pill bug, if you prefer).
Having a close encounter with our cat Berkeley last summer. I think Easty kinda blew Berkeley’s mind. She’s been around our other cat, Moe, for years, so she’s completely unfazed by cats. But Berkeley is a SoCal kitty who showed up on our doorstep starving and yowling when he was about eight weeks old, so this was his first encounter with a turtle.
Berkeley batted at Easty’s shell a couple of times and then spent about half an hour having a visible existential crisis. Here was a small creature that he couldn’t frighten and couldn’t move, which was not the least bit afraid of him and either ignored him or treated him like an obstacle. Watching them interact — or rather, watching Easty act and Berkeley react — was solid entertainment for most of the afternoon.
Why have I hijacked this post to yap about my turtle? Primarily because up until now I’ve had a hard time visualizing a stem turtle. Turtles are so much their own thing, and I’ve been so interested in them for virtually my entire life, that imagining an animal that was only partly a turtle was very difficult for me. The thing I like most about Brian’s art of the tumorous Pappochelys is that it reads convincingly turtle-ish to me, especially the neck and head:
So congratulations to Yara and her coauthors for a nice writeup of a very cool find, and to Brian for another vibrant piece of paleoart. Triassic turtles sometimes had cancer on their butts. Tell the world!
Since I’ve already blown the weekly schedule here in the new year, maybe my SV-POW! resolution for 2019 will be to blog more about turtles. I’m gonna do it anyway, might as well make it a resolution so I can feel like I’m keeping up with something. Watch this space.
Reference
Badgers are better than cats
April 2, 2016
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):
(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:
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.
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.
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.
Sauropod Vertebra Picture of the Week 