Monthly Archives: October 2020

James Herrmann’s mammal sculptures for the Cincinnati Museum Center

When last I blogged about James Herrmann’s art, it was about some cool sculptures of dinosaurs that he had done for the Cincinnati Museum Center. I am particularly taken with the sculptures that are skeleton on one side, and fully-fleshed on the other side.

Now he’s doing mammals, specifically Ice Age megafauna. 

And they’re attracting attention–this very cool American Mastodon won the Lanzendorf-National Geographic PaleoArt Prize in the 3D category at SVP this year.

As nice as the mastodon is, I am really taken with this Bison latifrons.

What can I say, I’m a sucker for high-spined vertebrae.

I really dig these, much more than I would either a naked skeleton or a fully-fleshed restoration on both sides. I hope there are more to come in the future, both from James and from other paleoartists.

For more on James’s work, please visit his website: http://www.herrmannstudio.com/.

I support #OpenAccess because …

We’re currently in open access week, and one of the things I’ve noticed has been a rash of tweets of the form “I support #OpenAccess because …”. Here is a random collection.

We support #OpenAccess because #OpenScience needs good infrastructures.
— @ZB_MED

We support #OpenAccess because we believe that research results made possible by public funds should be accessible to everyone.
— @TIBHannover

We support #openaccess because it is a powerful means to opening #knowledge to everyone, no matter the structural support of the recipient.
— @openaccessnet

I support #openaccess because it offers the chance to use published research optimally for the benefit of all – using free licenses. And open access has a really nice community.
— @tullney

We support #openaccess because it makes possible “the world-wide electronic distribution of the peer-reviewed literature and free and unrestricted access to it by all scientists, scholars, teachers, students, and other curious minds.”
— @opensciencebern

I support #openaccess because it is key to academic and scientific dialogue.
— @silkebellanger

I support #openaccess because I really believe that it contributes to a better world and does not cost more money but simply coordination.
— @chgutknecht

I support #openaccess because even as a researcher at a well-equipped university you often do not have (official) access to the required scientific literature (e.g. from another discipline).
— @dhuerlimann

I support #openaccess because it “accelerates research and all the goods that depend on research, such as new medicines, useful technologies, solved problems, informed decisions, improved policies, and beautiful understanding.”
— @petersuber

I support #openaccess because no one can predict who will want to use what piece of research when, and we should make sure there aren’t legacy restrictions in the way. We can do better.
— @researchremix

I support #OpenAccess because it is simply silly to spend years working hard to create new knowledge, then hide it in vaults where only a privileged few can see it.
— @MikeTaylor

I love that there are so many different reasons to support open access, from the most practical to the most fundamentally ethical. I love that the reach of open access is now so increased that even senior Elsevier staff like Head of communications P@ul Abrahams have the open-access-@-sign in their Twitter names. I love that cancelling Big Deals is no longer news — so many universities have done it, often with the help of organizations like Unsub who have a lot of experience in figuring out the financial implications.

It’s ridiculous that open access was ever a fight. But it was; and the thing is, it’s a fight that we’re winning.

The pararecurrent nerve in dogs, and sometimes people too

Altounian et al. (2015: fig 6).

As has been discussed here before, the recurrent laryngeal nerve (RLN) does not only innervate the larynx, but also parts of the esophagus and trachea (see this post, and in particular this comment). You can see that in this cadaver photo, in which the RLN is sending nice big visible branches into both the esophagus and trachea on its way to the larynx. Why is it doing this? Because the embryonic gut tube, which gives rise to both the digestive and respiratory systems, is serially innervated by the nerves of the pharyngeal arches that the gut tube passes through. Parts of the esophagus and trachea pass through the 4th to 6th pharyngeal arches, so they are innervated by the nerve that serves those arches, which is the recurrent laryngeal nerve. As discussed in the post and comment linked above, the recurrent course of the RLN to the esophagus and trachea is just as dumb as its recurrent course to the larynx, and equally strong evidence of a developmental constraint.

Although all tetrapods have an RLN that innervates the larynx, the axons to the esophagus and trachea aren’t always bound up with it. In dogs and many other mammals, those nerve fibers to the esophagus and trachea form a second recurrent nerve, the pararecurrent nerve or recurrent pharyngeal nerve. In this wonderful, complicated figure by Lemere (1932), the recurrent laryngeal nerve is labeled ‘r’, and the pararecurrent nerve is labeled ‘pa’.

Here’s Lemere’s figure with the RLN and pararecurrent nerve highlighted for easier comparison. The pattern of axonal wiring here is the same as in humans–all the axons have the same connections at the brainstem end on one hand, and at the pharynx and larynx end on the other hand–but the bundling of axons into what we recognize as peripheral nerves is different.

Interestingly, Lemere (1932) mentioned that having the recurrent pathways split into two nerves was the most common pattern in dogs, but occasionally he saw a case in which all of the axons had been bundled into a single RLN that served both the larynx and the esophagus and trachea, as in humans.

Modified from Altounian et al. (2015: fig. 4).

That door of variation swings both ways: a few years ago in our lab, we had a cadaver in which the left RLN only went to the larynx, and the vagus fibers to the esophagus and trachea were carried in a second, variant nerve. I didn’t know what that nerve was for a long time, until I stumbled onto the work of Lemere. So it seems that two nerves is the usual pattern for dogs, with one nerve as a rare variant, and the opposite is true in humans. 

Incidentally, I didn’t find the variant nerve in our lab, my students did. We got as far as putting together a manuscript, which we posted as a preprint (here), but we haven’t gotten it formally published yet. One of my goals for this year is to get some of these old, stalled projects dusted off and properly published. Watch this space.

I also discussed the pararecurrent nerve in my “How to make new discoveries in (human) anatomy” talk from SVPCA 2019, which is also a PeerJ preprint (here).

Other posts on the recurrent laryngeal nerve, and on the peripheral nervous system in general:

References

Three skulls in three dimensions

Get your red-cyan glasses — you do have some, right? — and check out this glorious image. Best full-screen it, it’s worth seeing!

And here is the lame 2D version for those of you who have still not spent 99 lousy cents on a pair of 3D glasses:

What are we looking at here?

Well, the smaller skull at bottom left is my new badger, which we saw a couple of days ago. Since then it has dried out, and I was easily able to figure out which teeth belong where, and glue them in with a drop of wood glue. I’ll photograph it in more detail at some point, but for those of you who can’t wait, there’s always the TNF of my first badger skull.

On the right is, if I’m not mistaken, a sheep — specifically a ram, given the horns. I don’t actually remember this one’s origin story, but it’s been sitting on a box next to our oil tank for a couple of years, with the flesh bits slowly decaying off and the bone cleaning itself up the way nature intended. A couple of days ago I cleaned it up a bit with my trusty toothbrush to remove some bits of moss and lichen, then soaked it for a few hours in very dilute bleach. It’s dried out beautifully, and is very robust. It’s big, too.

Everything else you see belongs to a deer — I assume, based on the horn bases. This is another one recovered from the depths of time. Some years ago, I put it a big water-filled pan and left it outside and forgot about it. In that time, not only had all the meat rotted off the bones, but the water had clarified and everything in it had died, so it didn’t even smell particularly. When I took the bones out, they were a nasty brown colour and little soft, and I thought I was going to have to discard them all. But once they had dried out they seemed a little more robust — though still brown. Then I left them overnight in dilute bleach, and when they had dried from that, they were their present much more appealing whitish colour, so I think they’re going to be OK.

Most of the cranium is intact in a single piece, though some of the sutures are wobbly and will need stabilising with wood glue. The mandible is in two parts, but both seem in decent condition. Right at the bottom left of the photo is a shard of bone by the tip of the mandible: this is the left nasal, which flaked off, but should be repairable. Everything else is vertebrae: atlas right behind the skull, axis by the snout, C3 just above it, and damaged C4 just below the atlas.

When it’s been put together a bit more, I will post some better photos, and I’ll see if anyone can identify the species.

My new badger skull (work in progress)

Last week, while Fiona and I were out walking, we noticed a decaying roadkill badger a bit over half a mile from our house. Yesterday we were out walking again, and we saw that it had decayed to the point where there was not much to the flesh at all. I prodded it with my foot and found that the skull was about ready to come away.

So when we got home, I popped straight back out in the car with some plastic bags which I used as improvised gloves, found the badger, managed to pull its head away from the remaining connective tissue (not a pleasant process) and bring it home. I simmered it gently for a couple of hours — outdoors on a portable hob, I’m not a barbarian — then cleaned it with a toothbrush and left it to cool. Today I soaked it in a soapy water for a couple of hours, then rinsed it off and soaked it in very diluted bleach for a couple more, taking care to harvest all the loose teeth that came out during each stage. Finally I rinsed it off, and here it!

European badger Meles meles, skull in left lateral view, with teeth. Pound coin for scale.

What next? I’ll give it couple of days to dry properly, then figure out which teeth go in which sockets and glue them in place. Then, bam, I have a second badger skull to go with my first, and I’ll be in a position to directly compare two skulls of the same animal.

This is a really nice, quick process compared with most of my preparations. The trick is to find a carcass that has already gone through the nastier stages of decomposition.

Note that the jaw is articulated, by the way. Unlike most animals, the skull of the badger locks the jaw in place with unusual joints in which the mandibular fossa of the cranium wraps around the cylindrical articular condyles of the jaw. I’ll try to include photos next time.

I leave you with a cheap-and-cheerful 3D anaglyph of the skull. Did I ever mention that you should get some cheap 3D glasses? You should get some cheap 3D glasses.