Here are some blank diagrams I whipped up for drawing in spinal cord pathways.

This one shows the whole cord, brainstem, thalamus, and cerebral cortex in coronal section, in cartoon form.

It’s for drawing in ascending sensory and descending motor pathways, as shown in this office hours sketch. DC-ML is dorsal column/medial lemniscus, which carries discriminative touch and conscious proprioception. ALS is anterolateral system, which carries pain, temperature, pressure, and itch. The lateral corticospinal tract carries fibers for voluntary control of major muscle groups. Each pathway differs in terms of where it decussates (crosses the midline, left-to-right and vice versa) and synapses (relays from one neuron to the next). The sensory pathways involve primary, secondary, and tertiary sensory neurons, and the motor pathways involve upper motor neurons (UMNs) and lower motor neurons (LMNs).

This one shows cross-sections of the cord at cervical, thoracic, lumbar, and sacral levels, for drawing ascending and descending pathways and thinking about how patterns of somatotopy come to exist.

Somatotopy is the physical representation of the body in the central nervous system. A common abbreviation scheme is A-T-L for arm-trunk-leg, as shown here for ascending sensory and descending motor pathways.

Finally, this one shows the spinal cord and spinal nerve roots at four adjacent spinal levels, for tracking the specific fates of sensory and motor neurons at each spinal level.

This is particularly useful when working out the consequences of an injury, like the spinal cord hemisection (Brown-Sequard syndrome) shown here in pink. The little human figure only shows the zone in which pain and temperature sensation are lost. There would also be losses of discriminative touch, conscious proprioception, and voluntary motor control on the same side as the injury.

Finally, since we’ve had a bit of a sauropod drought lately, here are a couple of photos of the mounted cast skeleton of Patagotitan in Stanley Field Hall at the Field Museum of Natural History in Chicago.

I gotta say, this mount beats the one at the AMNH in every way, because it’s well lit and you can move all the way around it and even look down on it from above. In fact, in terms of getting to move all the way around it, get well back from it to see the whole thing at once, and even walk directly underneath it (without having to ask permission to hop the fence), it might be the best-mounted sauropod skeleton in the world. The Brachiosaurus outside is also pretty great (evidence), but it loses points because you can’t walk around it on an upstairs balcony. Every other mounted sauropod I know of is either in more cramped surroundings, or you can’t get underneath it, or is less well-lit, or some combination of the above. Am I forgetting any worthy contenders? Feel free to make your case in the comments.

Incidentally, the spinal cord of Patagotitan was something like 120 feet long, and the longest DC-ML primary sensory neurons ran all the way from tail-tip to brainstem before they synapsed, making them among the longest cells in the history of life.

A belated thank-you to Josh Matthews and the rest of the Burpee PaleoFest crew for a fun day at the FMNH back in March. I got home from that trip about 3 days before the pandemic quarantine started, so it’s waaaaay past time for me to blog about how awesome that trip was. Watch this space.

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/.

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.

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

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.

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 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.

Accidental anaglyphs

October 16, 2020

Everyone knows that the very first thing you should do to improve your specimen photography is to use a tripod: it eliminates hand-shake and gives you much crisper photos. In most respects, my photographs have got much, much better since I’ve been habitually using a tripod.

But it has meant I’ve not been able to benefit from happy accidents like the one that gave me this 3D anaglyph of the Archbishop‘s Cervical S in dorsal view:

(Do you have red-cyan glasses? Yes? Good! You will be able to appreciate all the delicious morphological information in this photo. No? Go and order some right now — they cost literally a dollar.)

The reason I was able to make this very useful image is because back in the old pre-tripod days I would sometimes accidentally move a little bit between taking two more-or-less identical photographs. Here are the two images that I was able to composite into the anaglyph above:

Each of them is pretty uninformative alone: who can tell one nondescript area of brown bone from another? But when combined, they are extraordinarily more informative. If you don’t have 3D glasses then (A) get some! and (B) you can get some idea of how helpful the 3D information is from the crude wigglegram below, which simply switches back and forth between the two images.

And I can’t overstate how enormously helpful I have found these accidentally sourced anaglyphs as I write the descriptive part of the Archbishop manuscript. Even at this level of crudity, they have shown me several important points of morphology that I would certainly have missed if I’d been working only from my orthogonal-view photos, and saved me from more than one misinterpretation.

The moral is twofold:

  1. When taking specimen photographs, use a tripod — but deliberately get some pairs of shots where the camera is moved to the side by about 7 cm (the distance between the pupils in an average human).
  2. If you don’t have any red-cyan glasses, get some!

Well, one reason is the utterly rancid “block editor” that WordPress has started imposing with increasing insistence on its poor users. If there is one thing that world really doesn’t need, it’s a completely new way of writing text. Seriously, WordPress, that was a solved problem in 1984. As Henry Spencer very nearly said back in the eighties, “thy creativity is better used in solving problems than in creating beautiful new impediments to productivity“.

But enough pointless whining: instead, check out this bad boy:

Taylor (in prep. for 2020: Figure V). NHMUK PV R5937, “The Archbishop”, cervical vertebra V (most anterior preserved cervical vertebra, probably C6), left side still encased in plaster. A. Reconstruction of right lateral view with neural spine, prezygapophysis, diapophysis, condyle, cotyle and cervical rib restored. The prezygapophysis from the succeeding vertebra that has adhered to this element is shown in red. B. Dorsal view with anterior to the right. C. Posterior view. D. Right lateral view. E. Anterior view. F. Ventral view with anterior to the right. Scale bar 20 cm.

Yes, it’s your friend and mine, The Archbishop! It’s a big titanosauriform sauropod excavated by F. W. H. Migeod for the British Museum (Natural History) back in 1930, from the same Tendaguru Formation that yielded the awesome Giraffatitan specimens in the Museum für Naturkunde Berlin.

Yes, I admit I have been working on the Archbishop for more than sixteen years, and that I gave a talk about it at SVPCA 2005, and that I failed utterly to get it done as part of the Paleo Project Challenge 2010, and that as early as 2011 I was in despair about ever finishing it, and that I promised to do it by SVPCA 2016 but didn’t.

But in 2018 I did something significant, which was to actually start writing the paper in public. Now anyone can follow the progress of the project — and it’s progressing. The manuscript currently runs to about fifty printed pages, although that length is inflated by twenty-odd beautiful illustrations — of which the “Cervical V” image above is just one. (Do click through to see it in all its glory.)

So, yeah. That’s the main reason I am not blogging much. Because I am writing the paper. Finally.

Henry and Cheeto

This past summer, I got into a Facebook conversation with Steve Kary about turtles and tortoises. He was posting photos of Henry, his Russian tortoise (Agrionemys horsfieldii, formerly Testudo horsfieldii), and I was struck by how not-big Henry is. I am not a tortoise expert and what little direct experience I have is with desert tortoises and the big-to-giant species like Sulcatas and the Galapagos and Aldabra giant tortoises. I know the popular pet species like Greek and Russian tortoises and the small African species much less well. Offhand, Henry looked about as big as our three-toed box turtle, Easty (Terrapene carolina triunguis), so I asked Steve if he’d mind posting a photo with a scale bar. This is what Steve sent:

Clockwise from the top we have an ink pen, a 75-million-year-old caudal centrum of a crocodile, a bottle cap, a Nebulon-B frigate from Star Wars Armada, a screwdriver, a nail clipper, a small bottle of Tylenol, and a coin. Oh, and a DVD of an awesome movie.

Naturally, I felt compelled to respond in kind:

Here we have Easty with a similarly eclectic selection of small objects. Again from the top: a rat skull in a plastic bottle, a bottle cap, a d20, a small Altoids tin, an ink pen, a nail clipper, a small metal toy from China, and a nickel. Oh, and a DVD of an awesome movie. Yes, Easty is investigating the d20 as a possible food item. She tried to bite it, but since it’s bigger in diameter than her head, all she achieved was to send it shooting across the floor when her beak slammed shut on one of the vertices.

Here I’ve scaled the two photos to the same size. Henry is definitely wider than Easty, and he has a bigger head and chunkier-looking limbs. In fact, having spent most of my life around box turtles, that’s always my thought when I see a small tortoise: “How do they get so much critter into such a small shell?” It may have to do with space packing. Box turtles have to be able to pull everything in all the way so they can raise the drawbridge, as it were, and use their hinged plastron to close everything up tight (hence the name). Most tortoises lack hinged shells and use the tough scales on their legs and feet to complete the defensive perimeter between carapace and plastron. The limbs don’t have to pull all the way in, so they can be a little bigger.

Anyway, if you’d like to join in this pursuit–photographing turtles with collections of random objects–let me know in the comments. You can post your photos there, or I can add them to the body of the post.

Other turtle posts:

Here’s an odd thing. Over and over again, when a researcher is mistreated by a journal or publisher, we see them telling their story but redacting the name of the journal or publisher involved. Here are a couple of recent examples.

First, Daniel A. González-Padilla’s experience with a journal engaging in flagrant citation-pumping, but which he declines to name:

Interesting highlight after rejecting a paper I submitted.
Is this even legal/ethical?
EDITOR-IN-CHIEF’S COMMENT REGARDING THE INCLUSION OF REFERENCES TO ARTICLES IN [REDACTED]
Please note that if you wish to submit a manuscript to [REDACTED] in future, we would prefer that you cite at least TWO articles published in our journal WITHIN THE LAST TWO YEARS. This is a polict adopted by several journals in the urology field. Your current article contains only ONE reference to recent articles in [REDACTED].

We know from a subsequent tweet that the journal is published by Springer Nature, but we don’t know the name of the journal itself.

And here is Waheed Imran’s experience of editorial dereliction:

I submitted my manuscript to a journal back in September 2017, and it is rejected by the journal on September 6, 2020. The reason of rejection is “reviewers declined to review”, they just told me this after 3 years, this is how we live with rejections. @AcademicChatter
@PhDForum

My, my question is, why in such situations do we protect the journals in question? In this case, I wrote to Waheed urging him to name the journal, and he replied saying that he will do so once an investigation is complete. But I find myself wondering why we have this tendency to protect guilty journals in the first place?

Thing is, I’ve done this myself. For example, back in 2012, I wrote about having a paper rejected from “a mid-to-low ranked palaeo journal” for what I considered (and still consider) spurious reasons. Why didn’t I name the journal? I’m not really sure. (It was Palaeontologia Electronica, BTW.)

In cases like my unhelpful peer-review, it’s not really a big deal either way. In cases like those mentioned in the tweets above, it’s a much bigger issue, because those (unlike PE) are journals to avoid. Whichever journal sat on a submission for three years before rejecting it because it couldn’t find reviewers is not one that other researchers should waste their time on in the future — but how can they avoid it if they don’t know what journal it is?

So what’s going on? Why do we have this widespread tendency to protect the guilty?