Shoebills lie tell the truth (and it’s disgusting)
January 27, 2020
Heinrich Mallison sent me this amazing photo, which he found unattributed on Facebook:
Infuriatingly, I’ve not been able to track down an original source for this: searching for the text just finds a bunch of reposts on meme sites, and Google’s reverse image search just reports a bunch of hits on Reddit:
The line-drawing shows some scientific understanding of bird skeletons, so I imagine someone put real thought into this and is unhappy that the image is propagating uncredited. If that person reads this, please leave a comment: I’d love to credit it properly.
Anyway … what’s going on here?
Birds (like all vertebrates) have two tubes running down the ventral aspect of the neck (i.e. below the vertebrae): the trachea, for breathing, and the oesophagus, for swallowing. But these both open into the back of the mouth and are not piped up past it. I’ve not dissected enough bird heads to show this clearly, but when I was taking Veronica apart the trachea was pretty visibly ending in the mouth cavity, not plumbed up past the mouth into the nasal space:
So yes, I think it’s true: shoebills can bulge their spines out of their mouths.
Why? My best guess that there’s just nowhere else for the spine to go when the neck is retracted. There’s a big empty space in the mouth, why let it go to waste?
Turkeys lie
December 18, 2018
We all know what turkeys look like, right?
Turns out that two thirds of that bird is a lie. Here’s a diagram produced for hunters on which part of the turkey to shoot. (It’s all over the Internet, and I can’t trace the original source, but I got it from here):
Bascially, if you fire an arrow at a visible turkey, there’s a 2/3 chance that it’ll pass straight through feathers and completely miss the actual bird.
Now, then: what do we think a theropod looked like in life? Probably not much like what skeleton reconstructions show as the flesh envlope, as for example in Scott Hartman’s Guanlong:
Instead, it might have looked like this:
(Note: this is not in any way a criticism of Scott’s fine work, which is a scientific restoration of the soft tissue, and does not address integument at all.)
And now that pterosaurs have feathers, too(*), we have to assume that they, too, probably had body outlines bearing little resemblance to the flesh-on-bone shapes we’ve been used to seeing.
(*) As Matt pointed out: “I can’t be bothered to write “integumentary structures” when I mean “feathers”. I realize they may be independently derived, but eyes evolved independently like 40 times and we don’t refer to the other 39 instances as “photoreceptive structures”.” (He actually wrote “I can’t be arsed”, but I changed it to “bothered” to make him appear more professional.)
Necks lie: solitaire edition
May 2, 2018
Here at SV-POW! we’re big fans of the way that animals’ neck skeletons are much more extended, and often much longer, than you would guess by looking at the complete animal, with its misleading envelope of flesh.
Here’s another fine example, from John Hutchinson’s new post A Museum Evolves:
Solitaire (flightless bird), skeleton and taxidermy at University Museum of Zoology at Cambridge (UMZC). Photo by John Hutchinson.
Looking at the stuffed bird, it seems that it could get by perfectly well with half as many cervical vertebra, if only it didn’t carry them in such a strange posture.
Well — I say strange. It seems inefficient, yet it must be doing something useful, because it’s essentially ubiquitous among birds and many mammals … including rabbits, as long-time readers will remember.
Owl legs lie
May 12, 2017
Here is your occasional reminder of how very misleading feathers can be in understanding the true shape of an animal. An owl:
And the same owl showing a bit of leg:
And here are the two photos side by side:
We’ve often told you here on SV-POW! that necks lie. But legs lie, as well. Not to mention arms. Which is why so most of our life restorations of dinosaurs (theropods at least) probably look nothing like these animals looked in life.
Credit: I got the owl images from this Japanese page, but I have no idea where they originated. There are copies all over the Web, and figuring out which are the originals — if they’re even still up — would be a major research project. At any rate, you ought to be told that they are not my photos.
Necks Lie: the complete story
November 3, 2014
Just a quick post to link to all six (so far) installments of the “necks lie” series. I need this because I want to cite all the “necks lie” posts in a paper that I’ll shortly submit, and it seems better to cite a single page than four of them.
- Necks lie
- Necks lie, redux
- Sauropods still didn’t hold their necks in osteological neutral pose
- Hoatzins lie (and so do parrots)
- Herons:
- Necks lie: solitaire edition
- Shoebills
lietell the truth (and it’s disgusting)
I’ll update this post as and when we write more about lying necks.
Also:
What a world we live in.
X-ray of the neck of a seal, from Irish Seal Sanctuary. Note that the vertebral column becomes much more vertical than the fleshy envelope suggests.
Herons lie (and so do shoebills)
September 21, 2012
In a comment on the previous post, Emily Willoughby links to an excellent post on her own blog that discusses the “necks lie” problem in herons. Most extraordinarily, here are two photos of what seems to be the same individual:
You should get over to Emily’s blog right now and read her article. (Kudos, too, for the Portal reference in the title. I’ve been playing Portal and Portal 2 obsessively for the last week. Quite brilliant, and a very rare example of true innovation in computer gaming.)
Also of interest: this composite of two shoebill (Balaeniceps rex) individuals, which I made from two of the images mentioned in a comment by AL on Emily’s post:
Oh, birds, you crazy creatures!
Hoatzins lie (and so do parrots)
September 20, 2012
Back when we were at Cambridge for the 2010 SVPCA, we saw taxidermied and skeletonised hoatzins, and were struck that the cervical skeleton was so very much longer than the neck as it appears in life — because necks lie. At Oxford last week for the 2012 SVPCA, we saw a similar pair of hoatzin mounts (one adult, one juvenile) that clarified the situation:
And here is juvenile in side-view:
As you can see, it’s folding its neck way down out of the way, so that externally it appears much shorter. (And comparing with the Cambridge specimen, you can see that the neck skeleton is proportionally much longer than this in adult.)
Why does it do this? I have no idea.
But I do know it’s not unique to hoatzins. Another nice illustration of how misleading birds’ necks are when viewed in a live animal is this parrot (probably Amazona ochrocephala) in the Natuurhistorisch Museum of Rotterdam (from this Love in the Time of Chasmosaurs post):
One thing that’s not clear to me is how much of the neck the bird can extend in life. If the parrot wants to uncoil all that spare cervical skeleton to reach upwards or forwards, can it? Will the soft tissue envelope allow it? My guess is not, otherwise you’d surely see them doing it. But then … why is all that neck in there at all?
Necks lie, redux
September 1, 2011
In a recent post I showed photos of the trachea in a rhea, running not along the ventral surface of the neck but along the right side. I promised to show that this is not uncommon, that the trachea and esophagus of birds are usually free to slide around under the skin and are not constrained to like along the ventral midline of the neck, as they usually are in mammals. Here goes.
Here’s figure 5 from van der Leeuw et al. (2001): a lateral x-ray of a duck, reaching up just a bit with its head and neck, possibly to get a bite or just look around. Click through for the unlabeled version.
There’s a LOT of stuff going on in this image:
- As promised, the trachea (blue lines) is taking a very different path to the head than the vertebrae and skeletal muscles.
- As usual for tetrapods, the neck is extended
at the basein the caudal half and flexedat the headin the cranial half. - The epaxial (dorsal) muscles at the base of the neck are not tied down to the vertebral column so they are free to bowstring across the U-bend at the base of the neck (black arrow)–this was the point of the figure in the original paper. Although the gross outline of the neck also deviates from the vertebral column on the ventral side near the head, this is caused by the trachea and gullet approaching the pharynx, not because the hypaxial muscles are bowstringed across the curve.
- As the post title intimates, this neck lies: the cervical vertebrae are significantly more extended than one would expect based on the external appearance of the neck alone. The red line shows the angle of the most strongly retroverted vertebra, which I measure at 48.5 degrees from vertical (41.5 degrees above horizontal)–slightly closer to horizontal than to vertical! We have seen this before, in most mammals and in a couple of small birds (see this post); here we see it even in a reasonably large, long-necked bird.
- Worse, the gross outline of the neck–what one can see from the outside–lines up with nothing on the inside: the trachea is less curved and the vertebral column is more curved.
Same points again, this time in a chicken in an alert posture (Vidal et al. 1986: fig. 7). Here the most strongly retroverted cervical is 36 degrees from vertical (54 degrees above horizontal).
What’s all this got to do with sauropods?
First, it shows that even in animals with long, slender necks, it’s not enough to show a photo or painting of an extant animal and make assertions about what the cervicals are doing (necks lie, again). It’s even less defensible to make the dual assertions that (a) the gross outline of the neck shows the path of the cervicals and (b) the cervicals are in ONP, all based on a photo or painting of a living animal. The first point can only be established by radiography, and the second by manipulation of the skeleton, either physically or digitally. It may seem like I’m tilting at windmills here, but we’ve seen these very assertions made in conference talks. As always, we’ll follow where the evidence leads, but not until we see some actual evidence.
Second, I am increasingly haunted by the idea that we are all waaay too influenced, even (maybe especially) subconsciously, by big mammals when we think about sauropods and their necks. Big mammals–like, say, horses and giraffes–have:
- only 7 cervical vertebrae;
- lots of big muscles that attach to the thorax and the head and cross the cervical column without attaching to it much or at all;
- presacral neural spines that max out, height-wise, over the shoulders, creating withers;
- alert neck postures that are elevated (like all tetrapods) but often short of vertical, with the vertebrae often held more-or-less straight through the middle section of the neck (camels are an obvious exception here).
In contrast, birds have:
- many cervical vertebrae, from a 12 or so up to 27 or 28;
- almost no muscles that span from thorax to skull;
- presacral neural spines that rise monotonically to the synsacrum (except–maybe–in Giraffatitan);
- alert neck postures that are S-shaped, with the craniocervical joint over or just slightly in front of the cervicodorsal junction.
Which group sauropods had more in common with is left as an exercise for the reader.
References
- van der Leeuw, A.H.J., Bout, R.G., and Zweers, G.A. 2001. Evolutionary morphology of the neck system in ratites, fowl, and waterfowl. Netherlands Journal of Zoology 51(2):243-262.
- Vidal, P.P., Graf, W., and Berthoz, A. 1986. The orientation of the cervical vertebral column in unrestrained awake animals. Experimental Brain Research 61: 549-559.
Sauropods still didn’t hold their necks in osteological neutral pose
September 19, 2010
I’m just back from SVPCA 2010 (the Symposium of Vertebrate Palaeontology and Comparative Anatomy), and what an amazing meeting it was. I think it was the best I’ve been to. That’s partly because I understand more of the talks these days — it’s the first time I’ve ever listened to every single talk, even all the mammal-tooth and fish-skull talks — and I learned something interesting and new from almost every one of them.
But as is so often the case, the best thing about the meeting was, well, meeting. I met with Matt and Darren for the first time in a year, which is always excellent. And for the first time, I met horizontal-sauropod-neck advocate Kent Stevens. Kent was there to present one of two talks on horizontal necks, and UK sauropod jockey John Martin presented the other. Their talks were part of a block of seven sauropod talks — it would have been eight had Michael Pitman not changed his scheduled sauropod-tail talk to a theropod-tail talk. Matt and I both made presentations, although Darren wasn’t able to because he didn’t know that he’d be able to come to the meeting until the last moment.
After that block of talks, Matt, Darren and I went off to lunch with Kent and Martin. Despite the lighthearted attempts of session moderator John Hutchinson to build the session up as a two-way fight, it was all rather peaceful and enjoyable. After lunch we all went to have our photos taken together in front of the Zoology Museum‘s giraffe skeleton:
Sauropod Neck Posture Working Group, 2010 meeting. From left to right: Darren Naish, Matt Wedel, John Martin, Mike Taylor, Kent Stevens.
As you can see, we were all very civilised and well behaved.
The Sauropod Neck Posture Working Group carefully considers all points of view in a detached, professional and mature manner.
In all seriousness, it’s no secret that we SV-POW!sketeers are very much advocates of a raised habitual posture, and so that we strongly disagree with Kent and John. We had a lot of fun talking together, but we didn’t find that they presented any compelling new evidence in their talks. (You can read the abstracts of their talks, and indeed of mine and Matt’s, in the SVPCA abstracts book.)
The case for horizontal or near-horizontal habitual pose rests on two assumptions. First, that osteological neutral pose (ONP) was habitually adopted; and second, that we can know what ONP was. We still feel that both of these assumptions are false. We can’t know ONP because there is not a single sauropod neck skeleton anywhere in the world consisting of undistorted cervicals — and even if we knew what ONP was, it wouldn’t tell us much about what I am suddenly going to call mechanical neutral pose (MNP)[*], because we don’t know anything about the intervertebral cartilage. And we know that extant animals do not habitually adopt ONP because we have X-rays that show us how they habitually rest, and we know that they don’t match what you get by articulating bones.
[* either John or Kent made the point that ONP != MNP in his talk. I think they probably used a different name for MNP, but it eludes me for now. If anyone can remind me, I will switch to their terminology.]
So, anyway, it was a bit frustrating watching John’s talk, and seeing him show many photographs of live animals and claiming that their necks were in ONP, when we knew perfectly well that they were not — because necks lie. We fear he may have been tricked by the misleading soft-tissue outlines that mask the postures adopted by the neck skeleton in nearly all tetrapods. As an example, I give you the hoatzin, which happily was on display at the Zoology Museum as both a stuffed specimen and a skeleton:
Hoatzin (Opisthocomus cristatus), stuffed specimen and skeleton. Note the extraordinarily long cervical skeleton, almost entirely unreflected in the live animal.
Here’s another photograph from the astounding collection of the Zoology Museum (and some day I really ought to blog about the museum itself). I took this photograph of the neck of a camel with no specific agenda, but when I looked at it again today, one aspect leapt out at me:
Head and neck of dromedary camel (Camelus dromedarius) UMZC H.14191, in right lateral view, with disarticulated C3/C4 and C4/C5 joints.
Notice how very dramatically the third and fourth cervical central fail to contact, and the fourth and fifth. How uncomfortable this must be for the poor camel — its neck extended (or “dorsiflexed”) far, far out of ONP, to the point where the vertebrae drastically disarticulate. And yet we all know perfectly well that habitual pose for camels is much more extended than this, and many of us have seen photos of camels leaning their necks right back so that their heads are upside down, and they can rub the top of their head against their back. Just imagine what that does to the cervical articulations.
More on this subject another time. For now, I leave you with more from the Sauropod Neck Posture Working Group summit.
Hey! That hurt!
Necks lie
May 31, 2009
Since we’re spending a few days on neck posture, I thought I’d expand on what Mike said about bunnies in the first post: in most cases, it is awfully hard to tell the angle of the cervical column when looking at a live animal. Because necks lie.
Take this horse (borrowed from here). You can see that the external outline of the neck, which is what you would see in the living animal, is pointed in a different direction than the cervical column.
And here’s why. Many mammals carry their heads and necks so that the cranio-cervical joint is up high and the head is angled down from it. At the base of the neck, tall neural spines on the anterior thoracic vertebrae support the nuchal ligament, which lifts the body profile far above the cervical vertebrae. Basically, the cervicals run from the lower or middle part of the neck at its base to near the top of the neck at the head end.
This mismatch holds no matter how the neck and head are oriented. When the animal lowers its head to graze, the cervical column is still angled up relative to the apparent angle of the neck defined by its dorsal and ventral margins.
But if you think that’s bad, you ain’t seen nothin’ yet.
In most of the smaller birds, like this budgie (from Evans 1969:fig. 5-6) the neck is much longer and more flexible than you would think based on the external profile. And check out the mismatch between the cervical column (in front) and the trachea (behind). That’s not drawn incorrectly; the trachea is outside the bundle of neck muscles that encloses the vertebrae, and it is free to slide around all over the place, and does so in many birds.
Also note that while the neck is extended past vertical, the extension occurs in the middle of the neck, not at the shoulder. The neck actually goes down from the craniocervical joint, not up. My guess is that there is a lot of this in climbing taxa that hold their torsos elevated. Vultures come to mind here, too. A useful reminder that in natural history we are usually dealing with norms, not laws.
In the pigeon, note again the fact that the mid-cervicals are angled up much more sharply than is the external profile of the neck. In fact, the external profile of the neck is angled forward while the mid-cervicals are angled backward. This excellent reconstruction is from this page, which has several others which also show that necks lie.
Lest anyone think that the pigeon was either an outlier or a case of artistic embellishment, here’s yet another rabbit, this time from Vidal et al. (1986: fig. 5a). Again, the mid-cervicals–actually, almost all of the cervicals–are angled backward, but the neck as a whole is pointing slightly forward.
As an aside, I think possibly it has blown some people’s minds that we have used so many rabbits as examples, both in the paper and in our blog coverage. What can we say? Rabbits are awesome.
Of course not all necks lie. With flamingos, what you see is what you get.
Giraffes: 20 feet of reticulated irony
Let’s see here: necks not vertical.
Necks not vertical.
Trying . . . very . . . hard . . . and . . . just . . . getting . . . to . . . vertical!
(I know it looks like the neck is just slightly less than vertical, but remember that necks lie, and the cervical column is steeper. In this animal, you could drop a plumb bob from the ear and it would track the course of the cervical vertebrae just about perfectly.)
Cat, not trying at all: cervical column past vertical (Vidal et al. 1986: fig. 2).
Rat, taking its ease (top): cervical column vertical. Guinea pig, straight chillin’ (bottom): cervical column past vertical (Vidal et al. 1986: fig. 5 b and c).
Here’s the irony: for practically as long as sauropod neck posture has been contentious, giraffes have been held up as THE example of the most extreme (dude!) elevated neck postures out there. But in fact giraffes have to really reach to achieve vertical cervical postures that “ordinary” animals like cats, rats, guinea pigs, chickens, and, yes, rabbits, reach or exceed all the time.
Good paleobiology has to start with good biology. It’s high time that the sauropod neck posture debate got a reality infusion. Giraffe necks are extreme in terms of length, but not in terms of posture.
Speaking of sauropods…
All right, you’ve suffered long enough. Here’s your sauropod vert. Care to guess what it is?
References
- Evans, H.E. 1969. Anatomy of the budgerigar; pp. 45-112 in Petrak, M.L. (ed.), Diseases of Cage and Aviary Birds. Lea and Febiger, Philadelphia.
- Vidal, P.P., Graf, W., and Berthoz, A. 1986. The orientation of the cervical vertebral column in unrestrained awake animals. Experimental Brain Research 61: 549-559.
Sauropod Vertebra Picture of the Week 