Sauropod Vertebra Picture of the Week

Yesterday, I followed up Veronica‘s second simmering by taking more flesh off the bones, and in doing this I stared to take apart the bones that constitute the skull.  I assume you’re all keen to see pictures, so here she is upside down and in right posteroventrolateral view:

The interesting thing here is that I have removed all the cartilaginous hyoid apparatus, as I suspected last time that I’d end up doing, only to find that part of that apparatus was bony after all: the pair of slender anteromedially oriented bones that you see at the top of the photo.  Here they seem to be directly somewhat ventrally from back to front (i.e. upwards in the photo, since the head is upside down), but comparing with the earlier lateral-view photos of the intact and skinned head, I think that this is post-mortem displacement caused by cooking, and that in life they were more or less in the horizontal plane.

When I removed these bones, I found that their proximal ends were not articulated with other bones, but that they were extended by cartilage rods that continued posteriorly and seem to have been anchored only in soft tissue.  Is that weird?  Or should I have expected it?  It frightens me sometimes how little I know about heads.

You’ll also notice from this photo that I’ve now removed the anterior part of the neck that was attached to the head: as a result, I have a nice bonus set of atlas/axis complex, C3 and the front half of C4 (all pictured below).

Anyway, it was easy to tease away the soft tissue enclosing the mandibular joint and then to remove the bony mandible completely.  This they now do.  The mandible itself is amazingly lighlty built — see the photo at the end of this post, and more to the point the ones in the next post which I’ve not written yet.  Here’s the cranium in ventral view once the mandible was gone and I’d removed some of the skin from the roof of the mouth:

I’m not even going to expose myself to ridicule by attempting to identify any of the bones of the palate — that’s an area that I don’t know at all beyond the fact that there are things called “vomers”, which would make a good name for a race of bad guys in Buffy.  Clearly I need to get hold of a general bird-skull osteology.  Can anyone recommend anything?  Better still, can anyone offer a PDF?

Instead, let’s flip Veronica over and take a look at her top.  After the second simmering, the bones of her skull were very easy to disarticulate, so that’s what I’ve started to do here:

Those two main bones forming the crown of the skull are the frontals.  I assume those are elongate nasals in front of them, reaching down to the lateral edges of the snout (with the maxillae not visible in this view), but I don’t know what that tongue of bone on the midline is, between them: surely it’s too far back to be fused premaxillae?  Someone help me out here.

Anyway, the frontals lifted away cleanly and easily (the right frontal bringing its ?nasal with it, being still slightly attached).  This reveals how huge the eyeballs are (the big, black globes) and how relatively feeble the brain is (the pale brownish yellow lump between them):

It was easy enough to remove and discard the eyeballs and brain, and some surrounding gloop.  The parietal bones that form the back of the skull also came away easily.  At this stage I could have continued to tear the skull down but there are some very delicate bones along the midline and I thought it wiser to simmer again before tackling those.  So here is Veronica, as she was just before going into the pot for the third time, in right dorsolateral view:

It’s easy to make out the three cavities where the eyeballs and brain were.  There’s still a big mass of soft tissue in the middle of the skull, ahead of the eyes and behind the beak, but there’s no safe way to get at it until I’ve removed more of the bones — and those of the snout are very, very delicate.

Finally, here are the bones that I’ve removed from the main cranium (i.e. to get it into the state seen in the previous picture):

Top left (and facing left) is the mandible in dorsal view, and inside it the pair of hyoid bones, oriented as in life.  To the right of those are the ?nasals, then the frontals, then the parietals; outside the frontals are the ?lacrimals that I noted in the first post were coming away from their position in front of the orbit.

The bottom row is of course the vertebrae: atlas in posterior view, and axis, C3 and partial C4 in dorsal view, all facing to the left.

That’s all for now.  More to come.