Here’s an image that struck me as cool and possibly perplexing. And so we have another Mystery Anatomy post! Brought to you by some free time on my current trip to Gondwanaland.
Stomach-Churning Rating: 1/10; simple CT scan slice… of something.
Mystery Anatomy 2014: same rules as before; remember that the scoreboard has been reset.
Identify the animal in the CT slice shown above, as specifically as you can. No special rules.
Difficulty: Plenty.
Begin!
What's In John's Freezer? 
Hmm, must be a fossil then. The left hand side looks like some sort of spine or vertebra and the round bit could be a ribcage…. I’m a little puzzled by the two ends that connect the ‘ribcage’ to the ‘vertebra’ though, as a physiotherapist I’m much more familiar with human anatomy. A wild guess: some sort of labyrinthodont?
The overall shape makes think of a human cranium, but I can’t figure out the structures on the left of the image. I’m wondering if is a slice viewed from an unusual angle of about 45 degree to what we normally see through the occipital condyle and up through the frontal.
Looks like a really weird vertebra, so it must be from a pterosaur 😉
that looks like calcified gray mater over there. very Hamlet. a vertebra within a vertebra. beats me. I’m punting and going with cross section through an amphisbaenian.
It looks to me like a calcified eyeball, with a little floating lens at the front. I’m also going to guess that falls in the category of CT-pareidolia.
Round and looks kind of thin for how wide it is – maybe something small, not heavily loaded, or aquatic? Wild guesses: hydrocephalic infant just above the orbits or a small primate skull; tubey part of anteater, echidna or something like; or a baculum, with the strange bit being the groovy part?
I agree on the calcified eyeball, lens, ciliary body, vacuous space…
I’m leaning closer to Casey’s speculation in that this is a body cross-section. The problem is that there is even segmentation of the “round” structure with an indent at what I assume is the venter (right side of image) neatly bisecting the image.
The ring appears to be evenly and neatly segmented, implying, based on detail in closeup, they are osteoderms. The large Y-shaped ends of the ring around the midline structure are also segmented so one’s intial impression of “ribs” can be directly contradicted. And where does one get two-headed ribs that don’t attach to a clearly vertebra-shaped midline object? I’d think skull, but the high-segmentation seems to refute that, too. In the end, I am forced — compelled — to suggest that this is a tail cross-section in a highly ossified, bony tubular body, which is why Casey’s suggestion of an amphisbaenian seems so logical.
On the other hand, I’m also not familiar with some other particulars of anatomy, which has me thinking of the very few animals that completely surround an appendage with a bony ring, such as glyptodonts and some armadillos, all terrestrial turtles and in the cases of the tail or limbs some meiolaniid turtles, highly ossified crocodilians, some lizards such as helodermatids, etc. I’m actually pretty stumped.
A (possibly) pathological cranium of something? It’s definitely bone and probably not a fossil.
it could be either fossil or recent, but the fine trabeculae inside the bones make me think it’s likely recent. i thought of vertebra too, but a turtle came to my mind. although it’s too round for that. amphibaena? had to check digimorph, but i’m still not sure, those scales seem to bony..
what if that tiny thing is a vertebra? surrounded by something else? the ilium? then that would be the sacral region.. but an entirely closed one? and without fused sacral vertebra? plus a rounded ischium? or pubis? that doesn’t look like human vertebra right? some other primate? some other mammal? if it’s a fossil, then a marine reptile like, say, thalattosaurian? or placodontian? if it’s a fish after all, i’m doomed.. i know nothing about fishes. and you’re in OZ, gogo formation…
and what if that’s a hoof? of a horse for instance… or a camel.
if i keep guessing and eventually get it right, will i still get the points? :p
Answer time! Did anyone get it right?
NOOOOOOO! Boo hoo.
It is a cross-section of the carapace (body armour) of Tolypeutes matacus, the Southern three-banded armadillo!
Those are osteoderms and on the left side of the image, the xenarthran vertebra– reminiscent of this old mystery CT:
https://whatsinjohnsfreezer.com/2012/07/05/mystery-ct-slice-3-double-trouble/
Very tricky John, very tricky!
Scoreboard being updated now. You all get 2 pts for suffering through this tough mystery!
I quote mine ownself to be true:
“has me thinking of the very few animals that completely surround an appendage with a bony ring, such as glyptodonts and some armadillos,” [emphasis added]
And yea, though I verily recommend it, at least one point additional for the remarking of the possibiliy of the almost-ing the right answer!
*Beethoven’s 9th plays*
Shotgun approach is going to hit some of the time but I enjoyed your reasoning so kudos to you! (but no bonus pts) 😉
well, it was somehow related to the pelvis. i think that, since me and jaime were the closest, we deserve half a point more :p
Nuh uh! It’s ice cold in my heart as it is in my freezer.
Bony struts . . . bird or pterosaur.
I’ll plumb for a bird, the back of the skull with the occipital region to the left of the picture.
Oh blow. I’ve just realised how late I was as the answer has been posted> I didn’t read any of the other comments so I couldn’t be influenced. I was way out anyway.
+1 sympathy point for Stuart– LOL 😉
Curses! Can you show more of the vertebra? some 3Dviz? why is the spinal canal so tiny? Is that little black dot the spinal canal? Is that the sacrum then? please rename site to WTFsinjohnsfreezer.
Haha, yeah it’s wacky stuff! Spinal cord and sacrum yes! 3D viz we’re doing (Steve LeComber and me and student) soon! Meanwhile, check this out:
I’m a sucker for fun requests for more images!
Ohhh! its the transition into the tail.. how cool. very tricky!
[…] sheath/club of Meiolania! Reminiscent of this…fromOwen, R. (1888). On parts of the skeleton of Meiolania platyceps (Ow.). Philosophical […]