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!

Last night, I submitted a paper for publication — for the first time since April 2013. I’d almost forgotten what it felt like. But, because we’re living in the Shiny Digital Future, you don’t have to wait till it’s been through review and formal publication to read it. I submitted to PeerJ, and at the same time, made it available as a preprint (Taylor 2014).

It’s called “Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs”, and frankly the results are weird. Here’s a taste:

Taylor (2014:figure 3). Effect of adding cartilage to the neutral pose of the neck of Apatosaurus louisae CM 3018. Images of vertebra from Gilmore (1936:plate XXIV). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 1. If the slightly sub-horizontal osteological neutral pose of Stevens and Parrish (1999) is correct, then the cartilaginous neutral pose would be correspondingly slightly lower than depicted here, but still much closer to the elevated posture than to horizontal. (Note that the posture shown here would not have been the habitual posture in life: see discussion.)

Taylor (2014:figure 3). Effect of adding cartilage to the neutral pose of the neck of Apatosaurus louisae CM 3018. Images of vertebra from Gilmore (1936:plate XXIV). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 1. If the slightly sub-horizontal osteological neutral pose of Stevens and Parrish (1999) is correct, then the cartilaginous neutral pose would be correspondingly slightly lower than depicted here, but still much closer to the elevated posture than to horizontal. (Note that the posture shown here would not have been the habitual posture in life: see discussion.)

A year back, as I was composing a blog-post about our neck-cartilage paper in PLOS ONE (Taylor and Wedel 2013c), I found myself writing down the rather trivial formula for the additional angle of extension at an intervertebral joint once the cartilage is taken into account. In that post, I finished with the promise “I guess that will have to go in a followup now”. Amazingly it’s taken me a year to get that one-pager written and submitted. (Although in the usual way of things, the manuscript ended up being 13 pages long.)

To summarise the main point of the paper: when you insert cartilage of thickness t between two vertebrae whose zygapophyses articulate at height h above the centra, the more anterior vertebra is forced upwards by t/h radians. Our best guess for how much cartilage is between the adjacent vertebrae in an Apatosaurus neck is about 10% of centrum length: the image above shows the effect of inserting that much cartilage at each joint.

And yes, it’s weird. But it’s where the data leads me, so I think it would be dishonest not to publish it.

I’ll be interested to see what the reviewers make of this. You are all of course welcome to leave comments on the preprint itself; but because this is going through conventional peer-review straight away (unlike our Barosaurus preprint), there’s no need to offer the kind of detailed and comprehensive comment that several people did with the previous one. Of course feel free if you wish, but I’m not depending on it.

References

Gilmore Charles W. 1936. Osteology of Apatosaurus, with special reference to specimens in the Carnegie Museum. Memoirs of the Carnegie Museum 11:175–300 and plates XXI–XXXIV.

Stevens, Kent A., and J. Michael Parrish. 1999. Neck posture and feeding habits of two Jurassic sauropod dinosaurs. Science 284(5415):798–800. doi:10.1126/science.284.5415.798

Taylor, Michael P. 2014. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs. PeerJ PrePrints 2:e588v1 doi:10.7287/peerj.preprints.588v1

Taylor, Michael P., and Mathew J. Wedel. 2013c. The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs. PLOS ONE 8(10):e78214. 17 pages. doi:10.1371/journal.pone.0078214

The paper

Open access (CC By) at PeerJ:

  • Taylor, Michael P. 2014. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs. PeerJ 2:e712. doi:10.7717/peerj.712 [PDF]

The full peer-review history is available.

An earlier version of this paper was made available as PeerJ Preprint, which at that point had not yet been peer-reviewed:

  • Taylor, Michael P. 2014. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs. PeerJ PrePrints 2:e588v1. doi:10.7287/peerj.preprints.588v1

SV-POW! Posts

High-resolution figures

Figure 1: Charles R. Knight’s famous 1897 painting of sauropods, which were then considered amphibious. In the foreground, Apatosaurus (“Brontosaurus” of his usage) wades in a lake, its neck erect. In the background, Diplodocus wanders on the shore, its neck held low and horizontal. These differences in posture may not represent different perceptions of the habitual behaviour of these different taxa, merely the postures these individuals happened to adopt at a particular moment.

Figure 1: Charles R. Knight’s famous 1897 painting of sauropods, which were then considered amphibious. In the foreground, Apatosaurus (“Brontosaurus” of his usage) wades in a lake, its neck erect. In the background, Diplodocus wanders on the shore, its neck held low and horizontal. These differences in posture may not represent different perceptions of the habitual behaviour of these different taxa, merely the postures these individuals happened to adopt at a particular moment.

Figure 1. Increased angle of elevation at an intervertebral joint when cartilage is included. Posterior cervical vertebrae 13 and 14 of Diplodocus carnegii holotype CM 84, from Hatcher (1901:plate III), in right lateral view. Top: C13 (yellow) in osteological neutral posture, with the condyle of C14 embedded in the cotyle of C13 and with zygapophyseal facets maximally overlapped. Bottom: intervertebral cartilage (black) added, and C13 (blue) rotated upwards to accommodate it. Since the zygapophyses remain maximally overlapped, a line between the centre of their facets forms the axis of rotation (white dot); red lines join the centre of rotation to the most anterior point of the bony condyle and of the intervertebral cartilage. By similarity, the angle between the yellow and blue vertebrae is equal to that between the red lines.

Figure 2: Increased angle of elevation at an intervertebral joint when cartilage is included. Posterior cervical vertebrae 13 and 14 of Diplodocus carnegii holotype CM 84, from Hatcher (1901:plate III), in right lateral view. Top: C13 (yellow) in osteological neutral posture, with the condyle of C14 embedded in the cotyle of C13 and with zygapophyseal facets maximally overlapped. Bottom: intervertebral cartilage (black) added, and C13 (blue) rotated upwards to accommodate it. Since the zygapophyses remain maximally overlapped, a line between the centre of their facets forms the axis of rotation (white dot); red lines join the centre of rotation to the most anterior point of the bony condyle and of the intervertebral cartilage. By similarity, the angle between the yellow and blue vertebrae is equal to that between the red lines.

Figure 3: Close-up of area of rotation in Fig. 2. The two long lines, each of length h, connect the middle of the zygapophyseal facets to the anteriormost point of the condyle of the posterior vertebra and the cotyle of the anterior one. The short line of length t is projected at a right angle to the left line, and more or less connects the points on the condyle and cotyle. The angle between the two long lines is θ.

Figure 3: Close-up of area of rotation in Fig. 2. The two long lines, each of length h, connect the middle of the zygapophyseal facets to the anteriormost point of the condyle of the posterior vertebra and the cotyle of the anterior one. The short line of length t is projected at a right angle to the left line, and more or less connects the points on the condyle and cotyle. The angle between the two long lines is θ.

Figure 3. Effect of adding cartilage to the neutral pose of the neck of Apatosaurus louisae CM 3018. Images of vertebra from Gilmore (1936:plate XXIV). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 1. If the slightly sub-horizontal osteological neutral pose of Stevens and Parrish (1999) is correct, then the cartilaginous neutral pose would be correspondingly slightly lower than depicted here, but still much closer to the elevated posture than to horizontal. (Note that the posture shown here would not have been the habitual posture in life: see discussion.)

Figure 4: Effect of adding cartilage to the neutral pose of the neck of Apatosaurus louisae CM 3018. Images of vertebra from Gilmore (1936:plate XXIV). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 1. If the slightly sub-horizontal osteological neutral pose of Stevens and Parrish (1999) is correct, then the cartilaginous neutral pose would be correspondingly slightly lower than depicted here, but still much closer to the elevated posture than to horizontal. (Note that the posture shown here would not have been the habitual posture in life: see discussion.)

Figure 4. Effect of adding cartilage to the neutral pose of the neck of Diplodocus carnegii CM 84. Images of vertebra from Hatcher (1901:plate III). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 2.

Figure 5: Effect of adding cartilage to the neutral pose of the neck of Diplodocus carnegii CM 84. Images of vertebra from Hatcher (1901:plate III). At the bottom, the vertebrae are composed in a horizontal posture. Superimposed, the same vertebrae are shown inclined by the additional extension angles indicated in Table 2.

 

Just a quick post to link to all five (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.

I’ll update this post as and when we write more about lying necks.

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.

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.

 

The paper

And see also the followup:

  • Taylor, Michael P. 2014. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs. PeerJ 2:e712. doi:10.7717/peerj.712 [PDF]

SV-POW! posts

High-resolution figures

Figure 1. The world's biggest mounted skeleton: the sauropod Giraffatitan brancai. Mounted skeleton of Giraffatitan brancai paralectotype MB.R.2181 at the Museum für Naturkunde Berlin, Berlin, Germany. Lead author for scale, by the skeleton's elbow. This is the largest mounted skeleton in the world based primarily on real remains rather than sculptures. It is 13.27 m tall, and represents an animal that probably weighed about 20–30 tonnes[61]. Much larger sauropods existed, but they are known only from fragmentary remains.

Taylor and Wedel (2013c: Figure 1). The world’s biggest mounted skeleton: the sauropod Giraffatitan brancai. Mounted skeleton of Giraffatitan brancai paralectotype MB.R.2181 at the Museum für Naturkunde Berlin, Berlin, Germany. Lead author for scale, by the skeleton’s elbow. This is the largest mounted skeleton in the world based primarily on real remains rather than sculptures. It is 13.27 m tall, and represents an animal that probably weighed about 20–30 tonnes (Taylor 2009). Much larger sauropods existed, but they are known only from fragmentary remains.

Figure 2. Cervical vertebrae of a turkey and a sauropod. Representative mid-cervical vertebrae from a turkey (top) and the sauropod Giraffatitan brancai (bottom), not to scale. Each vertebra is shown in left lateral view (on the left) and posterior view (on the right). Articular surfaces, where each vertebra meets its neighbour, are highlighted in red (for the centra) and blue (for the zygapophyses). Articular surfaces that are concealed from view are cross-hatched: prezygapophyses face upwards and inwards, so that the facets are inclined towards the midline. In sauropods, the centra have ball-and-socket joints. In birds, the joints are saddle-shaped, and the anterior articular surface is hidden in lateral view. Despite numerous differences in detail, the bird and sauropods vertebrae strongly resemble each other in fundamentals.

Taylor and Wedel (2013c: Figure 2). Cervical vertebrae of a turkey and a sauropod. Representative mid-cervical vertebrae from a turkey (top) and the sauropod Giraffatitan brancai (bottom), not to scale. Each vertebra is shown in left lateral view (on the left) and posterior view (on the right). Articular surfaces, where each vertebra meets its neighbour, are highlighted in red (for the centra) and blue (for the zygapophyses). Articular surfaces that are concealed from view are cross-hatched: prezygapophyses face upwards and inwards, so that the facets are inclined towards the midline. In sauropods, the centra have ball-and-socket joints. In birds, the joints are saddle-shaped, and the anterior articular surface is hidden in lateral view. Despite numerous differences in detail, the bird and sauropods vertebrae strongly resemble each other in fundamentals.

x

Taylor and Wedel (2013c: Figure 3). Articulated sauropod vertebrae. Representative mid-cervical vertebra of Giraffatitan brancai, articulating with its neighbours. The condyle (ball) on the front of each vertebra’s centrum fits into the cotyle (socket) at the back of the preceding one, and the prezygapophyses articulate with the preceding vertebra’s postzygapophyses. These vertebrae are in Osteological Neutral Pose, because the pre- and postzygapophyseal facets overlap fully.

Taylor and Wedel (2013: Figure 4). Intervertebral articular discs of an ostrich (not to scale). Left: first sacral vertebra in anterior view, showing articular disc of joint with the last thoracic vertebra. Right: posterior view view of a cervical vertebra, with probe inserted behind posterior articular disc. The cervical vertebra is most relevant to the present study, but the the sacral vertebra is also included as it shows the morphology more clearly. These fibrocartilaginous articular discs divide the synovial cavity, like the articular discs in the human temporomandibular and sternoclavicular joints, and should not be confused with the true intervertebral discs of mammals and other animals, which consist of a nucleus pulposus and an annulus fibrosus.

Taylor and Wedel (2013c: Figure 4). Intervertebral articular discs of an ostrich (not to scale). Left: first sacral vertebra in anterior view, showing articular disc of joint with the last thoracic vertebra. Right: posterior view view of a cervical vertebra, with probe inserted behind posterior articular disc. The cervical vertebra is most relevant to the present study, but the the sacral vertebra is also included as it shows the morphology more clearly. These fibrocartilaginous articular discs divide the synovial cavity, like the articular discs in the human temporomandibular and sternoclavicular joints, and should not be confused with the true intervertebral discs of mammals and other animals, which consist of a nucleus pulposus and an annulus fibrosus.

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Taylor and Wedel (2013c: Figure 5). Intervertebral gaps in camel necks. Head and neck of dromedary camels. Top: UMZC H.14191, in right lateral view, posed well below habitual posture, with apparently disarticulated C3/C4 and C4/C5 joints. Photograph taken of a public exhibit at University Museum of Zoology, Cambridge, UK. Bottom: OUMNH 17427, in left lateral view, reversed for consistency with Cambridge specimen. Photograph taken of a public exhibit at Oxford University Museum of Natural History, UK. Inset: detail of C4 of the Oxford specimen, showing articulations with C3 and C5. The centra are separated by thick pads of artificial ‘‘cartilage’’ to preserve spacing as in life.

Figure 6. Range of motion in a vertebral joint. Range of Motion (ROM) illustrated schematically for a single intervertebral joint of Giraffatitan brancai. The grey-scale vertebrae are shown in Osteological Neutral Pose. The red vertebra has been rotated upwards (“extended”) until its postzygapophyseal facet overlaps 50% with the prezygapophyseal facet of the succeeding vertebra, in accordance with the assumption of Stevens and Parrish. Similarly, the blue vertebra has been rotated downwards (“flexed”) until 50% zygapophyseal overlap is achieved. Because the zygapophyseal articulations in the neck of Giraffatitan are some way anterior to the those of the centra, the relative movement of the articulating zygapophyseal facets is anteroventral–posterodorsal; in taxa such as the turkey in which the zygapophyseal articulation are directly above those of the centra, relative movement is anterior-posterior.

Taylor and Wedel (2013c: Figure 6). Range of motion in a vertebral joint. Range of Motion (ROM) illustrated schematically for a single intervertebral joint of Giraffatitan brancai. The grey-scale vertebrae are shown in Osteological Neutral Pose. The red vertebra has been rotated upwards (“extended”) until its postzygapophyseal facet overlaps 50% with the prezygapophyseal facet of the succeeding vertebra, in accordance with the assumption of Stevens and Parrish. Similarly, the blue vertebra has been rotated downwards (“flexed”) until 50% zygapophyseal overlap is achieved. Because the zygapophyseal articulations in the neck of Giraffatitan are some way anterior to the those of the centra, the relative movement of the articulating zygapophyseal facets is anteroventral–posterodorsal; in taxa such as the turkey in which the zygapophyseal articulation are directly above those of the centra, relative movement is anterior-posterior.

Figure 7. Measurement rig for necks. Measurement rig for intact turkey necks, constructed from Duplo bricks and baseboard. The neck is pushed into the angle between the back wall (yellow) and the left wall (red), and held straight along the back wall. The marker brick (blue) abuts the end of the neck: the distance between the left wall and the marker brick is the length of the neck between perpendiculars.

Taylor and Wedel (2013c: Figure 7). Measurement rig for necks. Measurement rig for intact turkey necks, constructed from Duplo bricks and baseboard. The neck is pushed into the angle between the back wall (yellow) and the left wall (red), and held straight along the back wall. The marker brick (blue) abuts the end of the neck: the distance between the left wall and the marker brick is the length of the neck between perpendiculars.

Figure 8. Cervical vertebra 7 from a turkey. Anterior view on the left; dorsal, left lateral and ventral views in the middle row; and posterior on the right.

Taylor and Wedel (2013c: Figure 8). Cervical vertebra 7 from a turkey. Anterior view on the left; dorsal, left lateral and ventral views in the middle row; and posterior on the right.

Figure 9. Functional length of a cervical vertebra. Functional centrum length of a cervical vertebra of a turkey. The measurement is taken between the inflection points of the saddle-shaped articulations at each end of the centrum, shown here by the blue arrow connecting the red lines that mark the position of the saddle points.

Taylor and Wedel (2013c: Figure 9). Functional length of a cervical vertebra. Functional centrum length of a cervical vertebra of a turkey. The measurement is taken between the inflection points of the saddle-shaped articulations at each end of the centrum, shown here by the blue arrow connecting the red lines that mark the position of the saddle points.

Figure 10. Modified calipers for measuring functional vertebral length. Modified calipers used to measure functional length of a turkey vertebra. The tooth glued to the left jaw protrudes into the transverse concavity of the anterior articular surface and the dorsoventral concavity of the posterior articular surface straddles the right jaw.

Taylor and Wedel (2013c: Figure 10). Modified calipers for measuring functional vertebral length. Modified calipers used to measure functional length of a turkey vertebra. The tooth glued to the left jaw protrudes into the transverse concavity of the anterior articular surface and the dorsoventral concavity of the posterior articular surface straddles the right jaw.

Figure 11. Fifth and partial sixth cervical vertebrae of Sauroposeidon. Photograph and x-ray scout image of C5 and the anterior portion of C6 of Sauroposeidon OMNH 53062 in right lateral view. The anterior third of C5 eroded away before the vertebra was collected. C6 was deliberately cut through in the field to break the multi-meter specimen into manageable pieces for jacketing (see [37] for details). Note that the silhouettes of the cotyle of C5 and the condyle of C6 are visible in the x-ray.

Taylor and Wedel (2013c: Figure 11). Fifth and partial sixth cervical vertebrae of Sauroposeidon. Photograph and x-ray scout image of C5 and the anterior portion of C6 of Sauroposeidon OMNH 53062 in right lateral view. The anterior third of C5 eroded away before the vertebra was collected. C6 was deliberately cut through in the field to break the multi-meter specimen into manageable pieces for jacketing (see Wedel and Cifelli 2005 for details). Note that the silhouettes of the cotyle of C5 and the condyle of C6 are visible in the x-ray.

Figure 12. CT slices from fifth cervical vertebrae of Sauroposeidon. X-ray scout image and three posterior-view CT slices through the C5/C6 intervertebral joint in Sauroposeidon OMNH 53062. In the bottom half of figure, structures from C6 are traced in red and those from C5 are traced in blue. Note that the condyle of C6 is centered in the cotyle of C5 and that the right zygapophyses are in articulation.

Taylor and Wedel (2013c: Figure 12). CT slices from fifth cervical vertebrae of Sauroposeidon. X-ray scout image and three posterior-view CT slices through the C5/C6 intervertebral joint in Sauroposeidon OMNH 53062. In the bottom half of figure, structures from C6 are traced in red and those from C5 are traced in blue. Note that the condyle of C6 is centered in the cotyle of C5 and that the right zygapophyses are in articulation.

Figure 13. Joint between sixth and seventh cervicals vertebrae of Sauroposeidon. X-ray scout image of the C6/C7 intervertebral joint in Sauroposeidon OMNH 53062, in right lateral view. The silhouette of the condyle is traced in blue and the cotyle in red. The scale on the right is marked off in centimeters, although the numbers next to each mark are in millimeters.

Taylor and Wedel (2013c: Figure 13). Joint between sixth and seventh cervicals vertebrae of Sauroposeidon. X-ray scout image of the C6/C7 intervertebral joint in Sauroposeidon OMNH 53062, in right lateral view. The silhouette of the condyle is traced in blue and the cotyle in red. The scale on the right is marked off in centimeters, although the numbers next to each mark are in millimeters.

Figure 14. Geometry of opisthocoelous intervertebral joints. Hypothetical models of the geometry of an opisthocoelous intervertebral joint compared with the actual morphology of the C5/C6 joint in Sauroposeidon OMNH 53062. A. Model in which the condyle and cotyle are concentric and the radial thickness of the intervertebral cartilage is constant. B. Model in which the condyle and cotyle have the same geometry, but the condyle is displaced posteriorly so the anteropos- terior thickness of the intervertebral cartilage is constant. C. the C5/C6 joint in Sauroposeidon in right lateral view, traced from the x-ray scout image (see Figure 12); dorsal is to the left. Except for one area in the ventral half of the cotyle, the anteroposterior separation between the C5 cotyle and C6 condyle is remarkably uniform. All of the arrows in part C are 52 mm long.

Taylor and Wedel (2013c: Figure 14). Geometry of opisthocoelous intervertebral joints. Hypothetical models of the geometry of an opisthocoelous intervertebral joint compared with the actual morphology of the C5/C6 joint in Sauroposeidon OMNH 53062. A. Model in which the condyle and cotyle are concentric and the radial thickness of the intervertebral cartilage is constant. B. Model in which the condyle and cotyle have the same geometry, but the condyle is displaced posteriorly so the anteroposterior thickness of the intervertebral cartilage is constant. C. the C5/C6 joint in Sauroposeidon in right lateral view, traced from the x-ray scout image (see Figure 12); dorsal is to the left. Except for one area in the ventral half of the cotyle, the anteroposterior separation between the C5 cotyle and C6 condyle is remarkably uniform. All of the arrows in part C are 52 mm long.

Figure 15. First and second dorsal vertebrae of Apatosaurus CM 3390. Articulated first and second dorsal vertebrae of Apatosaurus CM 3390. A. Digital model showing the two vertebrae in articulation, in left lateral (top) and ventral (bottom) views. B-G. Representative slices illustrating the cross-sectional anatomy of the specimen, all in posterior view. B. Slice 25. C. Slice 31. D. Slice 33. E. Slice 37. F. Slice 46. G. Slice 61. Orthogonal gaps are highlighted where the margins of the condyle and cotyle are parallel to each other and at right angles to the plane of the CT slice. 'Zygs' is short for 'zygapophyses', and NCS denotes the neurocentral synchondroses.

Taylor and Wedel (2013c: Figure 15). First and second dorsal vertebrae of Apatosaurus CM 3390. Articulated first and second dorsal vertebrae of Apatosaurus CM 3390. A. Digital model showing the two vertebrae in articulation, in left lateral (top) and ventral (bottom) views. B-G. Representative slices illustrating the cross-sectional anatomy of the specimen, all in posterior view. B. Slice 25. C. Slice 31. D. Slice 33. E. Slice 37. F. Slice 46. G. Slice 61. Orthogonal gaps are highlighted where the margins of the condyle and cotyle are parallel to each other and at right angles to the plane of the CT slice. ‘Zygs’ is short for ‘zygapophyses’, and NCS denotes the neurocentral synchondroses.

Figure 16. Dorsal vertebrae of Apatosaurus CM 11339. Articulated middle or posterior dorsal vertebrae of Apatosaurus CM 11339. A. X-ray scout image showing the two vertebrae in articulation, in left lateral view. B–D. Slices 39, 43 and and 70 in posterior view, showing the most anterior appearance of the condyles and cotyles.

Taylor and Wedel (2013c: Figure 16). Dorsal vertebrae of Apatosaurus CM 11339. Articulated middle or posterior dorsal vertebrae of Apatosaurus CM 11339. A. X-ray scout image showing the two vertebrae in articulation, in left lateral view. B–D. Slices 39, 43 and and 70 in posterior view, showing the most anterior appearance of the condyles and cotyles.

Figure 17. Effect on neutral pose of including cartilage on ONP. Effect on neutral pose of including cartilage. Top: dorsal view of a turkey cervical vertebra: vertical red line indicates the position of the most anterior part of the midline of the anterior articular surface, which is obscured in later view. Second row: two such vertebrae arranged in osteological neutral pose, with the articular surfaces of the centra abutting and the zygapophyseal facets maximally overlapped. The anterior vertebra is inclined by about 16° relative to the posterior. Third row: two such vertebra, with the centrum of the more posterior one elongated by 6.46% to allow for intervertebral cartilage (shown in blue), and the more anterior positioned with its centrum articulating with the cartilage and the zygapophyses maximally overlapped. The anterior vertebra is inclined by about 31°. The inclusion of cartilage has raised neutral posture by 15°. Green lines represent a horizontal baseline, joining the most ventral parts of the anterior and posterior ends of the vertebrae.

Taylor and Wedel (2013c: Figure 17). Effect on neutral pose of including cartilage on ONP. Effect on neutral pose of including cartilage. Top: dorsal view of a turkey cervical vertebra: vertical red line indicates the position of the most anterior part of the midline of the anterior articular surface, which is obscured in later view. Second row: two such vertebrae arranged in osteological neutral pose, with the articular surfaces of the centra abutting and the zygapophyseal facets maximally overlapped. The anterior vertebra is inclined by about 16° relative to the posterior. Third row: two such vertebra, with the centrum of the more posterior one elongated by 6.46% to allow for intervertebral cartilage (shown in blue), and the more anterior positioned with its centrum articulating with the cartilage and the zygapophyses maximally overlapped. The anterior vertebra is inclined by about 31°. The inclusion of cartilage has raised neutral posture by 15°. Green lines represent a horizontal baseline, joining the most ventral parts of the anterior and posterior ends of the vertebrae.

Figure 18. Cartilage in the neck of a rhea. Joint between cervicals 11 (left) and 10 (right) of a rhea, sagittally bisected. Left half of neck in medial view. The thin layers of cartilage lining the C11 condyle and C10 cotyle are clearly visible.

Taylor and Wedel (2013c: Figure 18). Cartilage in the neck of a rhea. Joint between cervicals 11 (left) and 10 (right) of a rhea, sagittally bisected. Left half of neck in medial view. The thin layers of cartilage lining the C11 condyle and C10 cotyle are clearly visible.

Figure 19. Alligator head and neck. Sagittally bisected head and neck of American alligator, with the nine cervical vertebrae indicated. Inset: schematic drawing of these nine vertebrae, from ([62]: figure 1), reversed.

Taylor and Wedel (2013c: Figure 19). Alligator head and neck. Sagittally bisected head and neck of American alligator, with the nine cervical vertebrae indicated. Inset: schematic drawing of these nine vertebrae, from Frey 1988: figure 1, reversed.

Figure 20. Horse head and neck. Sagittally bisected head and anterior neck of a horse. The first four cervical vertebrae are complete, but the posterior part of the fifth is absent. Note that the condyles are deeply embedded in their cotyles.

Taylor and Wedel (2013c: Figure 20). Horse head and neck. Sagittally bisected head and anterior neck of a horse. The first four cervical vertebrae are complete, but the posterior part of the fifth is absent. Note that the condyles are deeply embedded in their cotyles.

Figure 21. Camel neck in X-ray. X-ray image of a camel, with tracing to highlight the centra of cervical vertebrae 2–7. (C1 and the anterior part of C2 are obscured by the skull.) Note that most of the condyles do not even reach the posterior margins of their corresponding cotyles, let alone embed deeply within them.

Taylor and Wedel (2013c: Figure 21). Camel neck in X-ray. X-ray image of a camel, with tracing to highlight the centra of cervical vertebrae 2–7. (C1 and the anterior part of C2 are obscured by the skull.) Note that most of the condyles do not even reach the posterior margins of their corresponding cotyles, let alone embed deeply within them.

Figure 22. Dog neck in X-ray. Neck of a dog (dachsund), in X-ray, with the seven cervical vertebrae indicated. This photo has been used with permission from the Cuyahoga Falls Veterinary Clinic.

Taylor and Wedel (2013c: Figure 22). Dog neck in X-ray. Neck of a dog (dachsund), in X-ray, with the seven cervical vertebrae indicated. This photo has been used with permission from the Cuyahoga Falls Veterinary Clinic.

Figure 23. Neck of a young juvenile giraffe. Neck of a young juvenile giraffe, in various states of dissection, to scale. Top, the neck as received, skinned and stripped of skin, oesophagus and trachea. Second, the neck with most muscle removed and the nuchal ligament stretched out. Third, the vertebrae cleaned of soft tissue and cartilage, laid out with equal intervertebral spacing to attain the same total length as when intact (51 cm). Fourth, the vertebrae in the same condition but articulated as closely as possible, forming a misleading cervical skeleton measuring only 41 cm. Top image in left lateral view; second in right lateral view, reversed; third and fourth in left dorsolateral.

Taylor and Wedel (2013c: Figure 23). Neck of a young juvenile giraffe. Neck of a young juvenile giraffe, in various states of dissection, to scale. Top, the neck as received, skinned and stripped of skin, oesophagus and trachea. Second, the neck with most muscle removed and the nuchal ligament stretched out. Third, the vertebrae cleaned of soft tissue and cartilage, laid out with equal intervertebral spacing to attain the same total length as when intact (51 cm). Fourth, the vertebrae in the same condition but articulated as closely as possible, forming a misleading cervical skeleton measuring only 41 cm. Top image in left lateral view; second in right lateral view, reversed; third and fourth in left dorsolateral.

References

The following paper are cited in the captions of the figures above:

As I mentioned a few days ago, Matt and I have a couple of papers in the new PLOS ONE Sauropod Gigantism collection. We were each lead author on one and second author on the other, so for convenience’s sake we’ll refer to them as my paper (Taylor and Wedel 2013c on neck cartilage) and Matt’s paper (Wedel and Taylor 2013b on caudal pneumaticity.)

Mine is very simple in concept (although it ended up at 17 pages and 23 figures). It’s all about addressing one of the overlooked variables in reconstructing the postures of the necks of sauropods (and indeed of all tetrapods). That is, the spacing between consecutive vertebrae, and the effect this has on “neutral pose”.

The concept of “neutral pose” goes back to the DinoMorph work of Stevens and Parrish (1999). They defined it (p. 799) as follows: “We determined the neutral poses for each animal, wherein the paired articular facets of the postzygapophyses of each cervical vertebra were centered over the facets of the prezygapophyses of its caudally adjacent counterpart.”

x

Taylor and Wedel (2013c: Figure 3). Articulated sauropod vertebrae. Representative mid-cervical vertebra of Giraffatitan brancai, articulating with its neighbours. The condyle (ball) on the front of each vertebra’s centrum fits into the cotyle (socket) at the back of the preceding one, and the prezygapophyses articulate with the preceding vertebra’s postzygapophyses. These vertebrae are in Osteological Neutral Pose, because the pre- and postzygapophyseal facets overlap fully.

One of the more fundamental flaws in Stevens and Parrish (1999) is the assumption that animals habitually rest their necks in neutral pose — an assumption that is unsupported by evidence and, as it turns out, false (Vidal et al. 1986, Taylor et al. 2009). But let’s leave that aside for the moment, and consider what neutral pose actually represents.

The fact that there is even such a thing as neutral articulation between two consecutive vertebrae is due to there being three points of contact between those vertebra: as with the legs of a tripod, three points is the minimum number you need to fix an object in three-dimensional space. Two of these points are at the zygapophyses, as noted in the original definition above. The third point is the articulation between the centra.

The centrum has been curiously overlooked in discussions of neutral pose, but needless to say its length is crucial in establishing what is neutral. In the image above, if the centrum was longer, then the angle between the consecutive vertebrae would need to be raised in order to keep the zygapophyses articulated.

And of course it was longer in life, because of the cartilage in between the consecutive centra. (The use of the more specific term “osteological neutral pose” goes some way to recognising that tissues other than bone have been overlooked, but the problem has not really been addressed or even properly acknowledged in published works before our paper.)

xx

Taylor and Wedel (2013c: Figure 5). Intervertebral gaps in camel necks. Head and neck of dromedary camels. Top: UMZC H.14191, in right lateral view, posed well below habitual posture, with apparently disarticulated C3/C4 and C4/C5 joints. Photograph taken of a public exhibit at University Museum of Zoology, Cambridge, UK. Bottom: OUMNH 17427, in left lateral view, reversed for consistency with Cambridge specimen. Photograph taken of a public exhibit at Oxford University Museum of Natural History, UK. Inset: detail of C4 of the Oxford specimen, showing articulations with C3 and C5. The centra are separated by thick pads of artificial ‘‘cartilage’’ to preserve spacing as in life.

You simply can’t ignore cartilage when modelling neck postures and expect to get anything resembling a meaningful result. That is, presumably, the reason why the habitual posture of rabbits in life exceeds the most extended posture we were able to obtain when manipulating dry vertebrae of a hare: compare Vidal et al. (1986: fig. 4) with Taylor et al. (2009: fig. 1).

How big is the effect? That depends on the thickness of the cartilage and the height of the zygapophyses above the center of rotation. Here is an illustration that we should have put in the paper, but which inexplicably neither of us thought of:

figNEW-angle-at-zygs

Influence of intervertebral cartilage on vertebral articulation angle. Consider the posterior vertebra (black) as fixed. The blue vertebra represents neutral pose of the preceding vertebra with centra abutting and zygapophyseal facets maximally overlapped. The red vertebra indicates neutral pose once intervertebral cartilage is added between the vertebra (where else?) The green lines show the angle by which the more anterior vertebra must be inclined in order to accommodate the cartilage, and the magenta line shows the height of the zygapophyseal articulation above the center of rotation between the two vertebrae.

Here’s some elementary trigonometry. Suppose the intervertebral cartilage is x distance thick at mid-height of the centra, and that the height of the zygs above this mid-height point (the magenta line) is y. The triangle between the middle of the condyle of the posterior vertebra, the middle of the cotyle of the anterior one and the zygapophyseal articulation is near enough a right-angled triangle as makes no odds.

Consider the angle θ between the green lines. Sin(θ) = opposite/hypotenuse = x/y, and by similarity, the additional angle of inclination of the anterior vertebra is also θ.

But for small angles (and this is generally a small angle), sin(θ) ≈ θ. So the additional inclination in radians = cartilage thickness divided by zygapophyseal height. For example, in vertebrae where the zygs are 23 cm above the mid-height of the centra, adding 4 cm of intervertebral cartilage adds about 4/23 = 0.174 radians = 10 degrees of extra inclination. (That’s pretty similar to the angle in the illustration above. Eyeballing the cartilage thickness and zyg height in the illustration suggests that 23:4 ratio is about right, which is a nice sanity-check of this method.)

millionaire-stupid-contestant4

At this point, I am cursing my own stupidity for not putting this diagram, and the very simple calculation, into the paper. I guess that can happen when something is written in a hurry (which to be honest this paper was). The formula is so simple — and accurate enough within tolerances of inevitable measurement error — that we really should have used it all over the place. I guess that will have to go in a followup now. [Update, 5th November 2014. It’s long overdue, but that followup paper has finally been submitted and is available as a preprint.]

Anyway — next time, we’ll address this important related question: how thick, in fact, was the cartilage between the cervicals of sauropods?

References

Since I posted my photograph of the Cambridge University Zoology Museum’s dromedary camel in the last entry, I haven’t been able to get it out of my mind.  Here it is again, this time with the background removed:

You’ll remember from last time that the thing that struck me most powerfully about it was the huge disarticulations between the centra of C3, C4 and C5.  [Stevens and Parrish (2005:fig. 10.1A) illustrated the articulated cervical column of a dromedary camel Camelus dromedarius in osteological neutral pose, and it comfortably approximates life posture; but its vertebrae are very different from those of this specimen.  I don’t know what to make of this.  Are there dromedary subspecies?  If so, they are very different from each other; if not, then the individual variation is pretty amazing.]

The Cambridge mount made me wonder how the neck of that specimen would look if we moved it down into neutral pose — that is, keeping the zygapophyses maximally overlapped as they are in the mount, but bringing the centra together at the same time.  I tried it in GIMP (a free equivalent to the better-known PhotoShop), and here is the result:

Let’s be clear that photoshopping vertebrae is an inexact science at best: I am working here from a single photograph taken carelessly as one among a hundred taken opportunistically in a museum too awesome not to photograph; I can see the vertebrae only from one angle; judging the maximal zygapophyseal overlap is error-prone.

Still, even taking all of these factors into account, I found this pose striking.  It left me very much wanting to find a published osteology of the camel with better multi-view figures of the cervical vertebrae.  Sadly, it seems like there isn’t anything like that (though if you know better, PLEASE say so in the comments!)  But my search led me inevitably to tetrapod savant Darren Naish, and he pointed me to Maziersky (2010), a book review which includes the following photo:

Camel with raised neck, from Maziersky (2010:fig. 2)

Judging by the odd way the camel is propped up on a table, this is a dead animal being posed rather than a live one adopting a posture voluntarily, but it does appear that this is at least a pose that the mechanics of the animal allow.  And that got me thinking about how the vertebrae must be arranged to allow this.  Here’s the best I’ve been able to come up with:

In comparison with the mounted skeleton’s pose, this re-articulates cervicals 3 and 4; but 4 and 5 remain horribly disarticulated, and the 5-and-6 and 6-and-7 pairs are now also in this state.

(A reminder is due again here that what I am doing is an approximate and error-prone process.  No doubt I got the maximal possible zygapophyseal disarticulation wrong in several places, for example.  But even allowing for that, I find this pretty amazing.)

If you’re wondering why the two earlier images had so much blank space at the top and this one has so much to the right, it’s because I made them all the same size and shape.  This means that if you open all three images in different browser tabs, then tab between them, you should see the neck neatly moving between the three different poses.  For those of you too lazy or technophobic to do that, here is a superposition:

Habitual posture (i.e. when the animal is not eating or drinking or otherwise doing anything in particular with its head) is somewhere above the mounted pose, but less extended than the raised pose shown by Maziersky.

What does all this tell us?

Nothing very encouraging, I’m afraid.   Even allowing for the vagaries of photoshopping images of museum mounts, it’s apparent that something very weird is going on in this camel’s neck, such that even a pose well below the habitual one requires extensive vertebral disarticulation.  Assuming that, like me, you don’t believe the vertebrae really are disarticulating in life, we can only conclude that it is useless to try to reach conclusions about neck posture based on osteology alone.  We need to understand the soft-tissue systems — especially the articular cartilage — as well.

Stevens and Parrish (1999:798) stated that “in vivo, muscles, ligaments, and fascia may have further limited movement [i.e. beyond the restrictions imposed by maintaining zygapophyseal overlap]; thus, the digital manipulations reported here represent a ‘best case’ scenario for neck mobility.”  Although this seems intuitively appealing, evidence including but not limited to the Cambridge camel shows that the opposite is actually the case: in at least some taxa, and maybe all, soft tissue enables necks to be more flexible, not less, than the bones alone suggest.

Folks, we’re flying blind.  Until we start to understand the soft tissues in the necks of extant critters — especially the intervertebral cartilage, but I bet that’s not the whole story — we really have no idea how to interpret the bones.

Come on, neontologists!  Teach us about intervertebral cartilage!

References

Special bonus archosaur-rich artwork

Check out John Conway’s obscenely brilliant infinite-zoom Jehol video.  (Well, a lot of people have been calling it infinite zoom, but it’s clearly finite.  Still, it’s at least Very Big Zoom.)  A lot of jaws dropped at SVPCA in Cambridge when John was showing this off.  While you’re at it, you might like to read the interview with John at Dave Hone’s Archosaur Musings.  Dave’s interviewed quite a few palaeoartists now, but John has more to say than most of them, and it’s well worth a read.

Special bonus horror story

While I was emailing with Darren about camels, he told me that John Hutchinson had recently acquired a camel at the RVC, and suggested that I ask to be present at the dissection of the neck.  I contacted John only to be told: “Just got the feet; had no time to get the rest, sadly. Notice came at a bad time for my group, as it tends to do. It is now incinerated.”  John also told me at SVPCA of a hippo that was recently incinerated because he couldn’t get to the zoo to collect it within 24 hours.  Graaaggh!  It’s a tragedy the dead animals that go to waste.

Momentous news: we SV-POW!sketeers have finally gotten off our collective duff and published something together. Here are the goods:

The Paper

Freely available to the world right now, thanks to the wonder of Open Access:

Taylor, Michael P., Mathew J. Wedel and Darren Naish.  2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54(2): 213-220.

Unofficial Supplementary Information Online

The short short version plus some pretty pictures here, hi-resolution colour versions of the figures here.

SV-POW! Posts About the Paper

… and, well over a year later …

(The sequence of neck-posture posts led into a a broader discussion of the interaction between blog posts such as these and format publications: there’s an overview at The Shiny Digital Future.)

Television

Mike was interviewed live on Channel 4 News at 12.20pm.  At the time of writing, the video is freely available on the Channel 4 web-site, though it may not last long: anyone who can help me to download a permanent copy will earn my gratitude.  Here is a larger version — though still not downloadable, only streamable.

Radio

Darren was interviewed on Radio 5 Live at 3.30pm, as part of the Simon Mayo Show, with stand-in host Richard Bacon.  Listen to an MP3 of Darren [2:30].

Mike was interviewed for several BBC stations:

And two days later (28th May) by:

Online News Coverage

Anything we missed below is probably available through Google News.

Blog Coverage

… and probably more that we’ve not got to yet.

Print Coverage

Scans of printed newspapers that I (Mike) bought on the day.  Click through for full-size scans.

The Guardian

The Guardian

The Times

The Times

The Independent

The Independent

The Telegraph; and, no, there really wasn't any other text besides the image caption.

The Telegraph; and, no, there really wasn't any other text besides the image caption.

The Mirror

The Mirror

The Sun

The Sun

Metro (London's free daily)

Metro (London's free daily)

Glasgow Herald (regional)

Glasgow Herald (one of the two Scottish daily newspapers)

Do you want to know how stupid my co-blogger Matt Wedel is?  Having already discussed the ostrich Struthio camelus in Wedel et al. (2000b), that total idiot went on to misspell the trivial name as “camellus” in Wedel and Cifelli (2005:52).  What a doofus.

And do you want to know how dumb my other co-blogger Darren Naish is?  Throughout Naish and Dyke (2005), he consistently misspelled the species name of Elopteryx nopcsai as “nopscai“, despite extensively discussing Nopcsa, who the species was named after.  What a moron.

It’s a good thing I would never do anything so stupid.

Er.  Read on …

Brachiosaurus altithorax holotype FMNH P25107, last five dorsal vertebrae in right lateral view.  Photograph by Phil Mannion.

Brachiosaurus altithorax holotype FMNH P25107, last five dorsal vertebrae in right lateral view. Photograph by Phil Mannion.

So I have this paper in press about the two “Brachiosaurus” species and how they are not really congeneric — I think we’ve mentioned it a few times.  It’s now very nearly a year since I submitted it, under the title: A re-evaluation of Brachiosaurus altithorax Riggs 1904 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai Janensch 1914.  And now — now, a year on, after having re-read this manuscript some insane number of times — I finally notice my own grotesque error: Riggs of course named B. altithorax in 1903.  Argh!  So in the last few days, I’ve spent some crazy amount of time going through and changing this title in my dissertation (where it pops up as Chapter 2), in my CV, in my on-line publications list … and of course, making a GIGANTIC sign in flashing red neon, to be suspended before my eyeballs at all times, reminding me to fix this in the page-proof when that turns up.

(Actually, I think this error is the most astounding of all: not only did I miss it myself, but so did my Ph.D supervisor, the handling editor at SVP, both peer-reviewers, the self-invited third “reviewer” who sent his unsolicited comments, both of my examiners and the two or three people that I’ve sent preprints to.  Incredible that ten or more people could all miss such a horribly obvious mistake right there in the title.)

So.  You’d think that just about exhausted Matt’s, Darren’s and my doofosity, right?  Oh ho ho.  Not so, because we have a paper in press that we wrote together.  We submitted it, revised it according to the reviews, commented on the page-proofs and told the journal it was all ready to go.  And then — THEN — we noticed a horrible, stupid mistake right in the middle of the abstract.  The paper is about osteological neutral pose, but we’d written “osteological neural pose”.  And all three of us missed it.  (Happy ending: we told the journal what we’d done, and it wasn’t too late to fix.)

So the moral of the story is: we are idiots.

Just thought you ought to know.

References

Last October, Mike posted a tutorial on how to choose a paper title, then followed it up by evaluating the titles of his own papers. He invited me to do the same for my papers. I waited a few days to allow myself to forget Mike’s comments on our joint papers – not too hard during my fall anatomy teaching – and then wrote down my thoughts.

And then did nothing with them for three and a half months.

The other day I rediscovered that draft and thought, hey, I don’t remember anything I wrote back then, I should redo the experiment and see if my evaluations will be consistent. And this time without looking at Mike’s post at all, so the risk of contamination would be even lower.

BUT FIRST I thought I should write down what I admire in paper titles, so I could see whether my titles actually lived up to my ideals. So now we can compare:

  • what I say I like in paper titles;
  • what I actually titled my papers;
  • what I had to say about my titles last October;
  • what I have to say about them now;
  • and, for some of my papers, what Mike had to say about them.

What I Admire In Paper Titles

Brevity. I first became consciously aware of the value of concise titles when I read Knut Schmidt-Nielsen’s autobiography, The Camel’s Nose, in 2004 or 2005. (Short-short review: most of the book is a narrative about scientific questions and it’s great, the self-congratulatory chapters near the end are much less interesting. Totally worth reading, especially since used copies can be had for next to nothing.) Schmidt-Nielsen said he always preferred short, simple titles. Short titles are usually punchy and hard to misunderstand. And I like titles that people can remember, and a short title is easier to recall than a long one.

Impact. In short, maximum information transfer using the minimum number of words. This is a separate point from sheer brevity; a paper can have a short title that doesn’t actually tell you very much. But brevity helps, because it’s difficult to compose a long title that really hits hard. Whatever impact a title might have, it will diluted by every extraneous word.

Full sentences as titles. This is taking the information-transfer aspect of the last admirable quality to its logical extreme, although often at the expense of brevity. I was heavily influenced here by two things that happened while I was at Berkeley. First, I taught for a year in an NSF GK-12 program, where graduate students went out into local elementary, middle, and high schools and taught biology enrichment classes. One thing that was drilled into us during that experience is that we were teaching concepts, which ideally would be expressed as complete sentences. Also about that same time I read James Valentine’s book On the Origin of Phyla. The table of contents of that book is several pages long, because every chapter title, heading, and subheading is a complete sentence. This has a lovely effect: once you’ve read the table of contents of the book or any of its parts, you’ve gotten the TL;DR version of the argument. Sort of like a distributed abstract. I’d like to do that more.

How Did I Do?

Time to see if my actions match my words. Full bibliographic details and PDFs are available on my publications page. I stuck with Mike’s red-blue-green color scheme for the verdicts. My October 2014 and February 2015 thoughts are labeled. For joint papers with Mike, I’ve copied his assessment in as well. Any comments in brackets are my editorializing now, comparing what I said in October to what I said a few days ago before I’d looked back at my old comments or Mike’s.

* * * * * * * * * * * *

Sauroposeidon proteles, a new sauropod from the Early Cretaceous of Oklahoma. (11 words)

GOOD
Oct 2014: Like it. Short, to the point, includes the taxon name.
Feb 2015: Good, gets the job done with a minimum of fuss

Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon. (9 words)

OK
Oct 2014: This title was inspired by the papers from the early 20th century
Feb 2015: It gets the job done, I suppose. I can’t help but wonder if there might have been a more elegant solution. Part of my unease is that this title is an example of the same attitude that produced the next monstrosity.

Osteological correlates of cervical musculature in Aves and Sauropoda (Dinosauria: Saurischia), with comments on the cervical ribs of Apatosaurus. (19 words)

BAD
Oct 2014: Ugh. It gets the job done, I suppose, but it’s waaaay long and just kind of ugly.
Feb 2015: Ugh. Waaay too wordy. I had a (fortunately brief) fascination with long titles, and especially the phrase, “with comments on”. Now I would cut it down to “Bony correlates of neck muscles in birds and sauropod dinosaurs” (10 words)

Vertebral pneumaticity, air sacs, and the physiology of sauropod dinosaurs. (10 words)

OK
Oct 2014: Like it. Would be better made into a sentence, like, “Vertebral pneumaticity is evidence for air sacs in sauropod dinosaurs.”
Feb 2015: Fairly clean. Does what it says on the tin. I’m having a hard time seeing how it could be turned into a sentence and still convey so much of what the paper is about in so few words.

[Heh. As we will see again later on, I was evidently smarter last fall than I am now.]

The evolution of vertebral pneumaticity in sauropod dinosaurs. (8 words)

GREAT

Oct 2014: Like it. It couldn’t really be any shorter without losing crucial information. Happy to have a decent title on my second-most-cited paper!
Feb 2015: Short, clean, probably my best title ever.

First occurrence of Brachiosaurus (Dinosauria: Sauropoda) from the Upper Jurassic Morrison Formation of Oklahoma. (14 words)

OK
Oct 2014: Yep. once you’ve read the title, you barely need to read the paper. Even better would have been, “A metacarpal of Brachiosaurus from the Upper Jurassic Morrison Formation of Oklahoma.” (12 words)
Feb 2015: Does what it says, but like my other PaleoBios pub, it’s a long title for a short paper. Now I would title it, “First record of the sauropod dinosaur Brachiosaurus from Oklahoma” (9 words)

[my October title was better!]

Postcranial skeletal pneumaticity in sauropods and its implications for mass estimates. (11 words)

OK
Oct 2014: It’s not elegant but it gets the job done. I wanted that paper to be one-stop shopping for sauropod PSP, but of course the real payoff there is the ASP/mass-estimate stuff, so I’m happy to have punched that up in the title.
Feb 2015: Good enough. I like it. It’s a little long–I could reasonably have just titled this, “Postcranial skeletal pneumaticity in sauropods”, but I wanted to draw attention to the implications for mass estimates.

Sauroposeidon: Oklahoma’s native giant (4 words)

OK
Feb 2015: Nice and short. Not terribly informative, but since this was a narrative about the discovery and description of Sauroposeidon aimed mostly at an Oklahoma audience, it’s not obvious how it could be improved.
[Note sure how missed this one last October, but I did.]

Origin of postcranial skeletal pneumaticity in dinosaurs. (7 words)

GOOD
Oct 2014: About all I would change now would be to add the word “early” at the beginning of the title.
Feb 2015: Great. Could not be shortened further without losing information.

What pneumaticity tells us about ‘prosauropods’, and vice versa. (9 words)

GOOD

Oct 2014: Love this title. I used it for the abstract of the SVP talk that the paper was derived from, too.
Feb 2015: Kind of a gimmick title, but it’s accurate–the SVP abstract this paper was based on was built around a bullet list. And it’s still nice and short.

Evidence for bird-like air sacs in saurischian dinosaurs. (9 words)

GOOD

Oct 2014: Along with Wedel (2003b) and Wedel (2006), this has a short (7-9 words apiece) title that tells you what’s in the paper, simply and directly. For once, I’m glad I didn’t turn it into a sentence. I think a declarative statement like “Saurischian dinosaurs had air sacs like those of birds” would have been less informative and come off as advertising. I wanted this paper to do what the title said: run down the evidence for air sacs in saurischians.
Feb 2015: I like it and wouldn’t change it. The “evidence for” part is key – I didn’t want to write a paper primarily about the air sacs themselves. Instead I wanted to lay out the evidence explaining why we think sauropods had air sacs.

Head and neck posture in sauropod dinosaurs inferred from extant animals. (8 words)

OK
Oct 2014: It’s not horrible but it would be better as a declarative statement like, “Sauropod dinosaurs held their necks and heads elevated like most other tetrapods.” (12 words)
Feb 2015: Good. Reads almost telegraphically brief as it is. Does what it says on the tin.

Mike: RUBBISH

[October Matt wins again!]

A new sauropod dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA. (13 words)

OK
Oct 2014: Two things about this one. First, I wish we’d been able to include the taxon name in the title, as we were allowed to do back in the day for Sauroposeidon. Second, I know some people whinge about us using the CMF in the title and in the paper instead of the Burro Canyon Fm, which is what the CMF is technically called east of the Colorado River. But srsly, how many people search for Burro Canyon Fm versus CMF? All of the relevant faunal comparisons are to be made with the CMF, so I don’t feel the least bit bad about this.
Feb 2015: Fine. About as short as it could be and still be informative.

Mike: RUBBISH

The long necks of sauropods did not evolve primarily through sexual selection. Journal of Zoology. (12 words)

GOOD
Oct 2014: Perfect. The abstract and the paper expand on the title, but if all you read is the title, you know what we found. That’s a worthy goal.
Feb 2015: My first sentence title. Every word does work, so even though this is one of my longer titles, I like it. The length relative to my other titles is not a knock against this one; rather, it emphasizes how well I did at keeping my early titles short and to the point (with a couple of regrettable exceptions as noted above).

Mike: SWEET

The early evolution of postcranial skeletal pneumaticity in sauropodomorph dinosaurs. (10 words)

GOOD
Oct 2014: Not bad. I wonder if something like, “Widespread vertebral fossae show that pulmonary pneumaticity evolved early in sauropodomorphs” might be better. It’s hard, though, to put so many long, polysyllabic words in a title that doesn’t sound like a train wreck. At a minimum, this paper does what it says on the tin.
Feb 2015: Short and to the point. Another one that couldn’t be any shorter without losing valuable information.

A monument of inefficiency: the presumed course of the recurrent laryngeal nerve in sauropod dinosaurs. (15 words)

Objectively: BAD to OK
Subjectively: GOOD to FREAKIN’ AWESOME
Oct 2014: I readily admit that I could have fashioned a more informative title, but I dearly love this one. It’s derived from a TV commercial for cheeseburgers (true story), and it warms my heart every time I read it.
Feb 2015: This is definitely a gimmick title that is longer than it has to be (it would be a concise 11 words without the unnecessary intro clause) BUT I love it and I’d do it exactly the same if I could do it again. So there!

Why sauropods had long necks; and why giraffes have short necks. (11 words)

GOOD
Oct 2014: This is one of those ‘draw the reader in’ titles. I like it.
Feb 2015: We both liked the even shorter, “Why giraffes have short necks” but we really felt that a paper about sauropod necks needed sauropod necks in the title. I feel about this one like I feel about my 2007 prosauropod paper: it’s a gimmick title, but it’s short, so no harm done.

Mike: EXCELLENT

Neural spine bifurcation in sauropod dinosaurs of the Morrison Formation: ontogenetic and phylogenetic implications. (14 words)

OK
Oct 2014: Blah. It’s okay, not great. Maybe better as, “No evidence for increasing neural spine bifurcation through ontogeny in diplodocid sauropods of the Morrison Formation”, or something along those lines.
Feb 2015: This one is long but I think the length is necessary. It’s also kinda boring, but it was addressing a fairly dry point. I think any attempt to shorten it or sexy it up would come off as gratuitous.

Mike: WEAK

The effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs. (18 words)

OK
Oct 2014: Probably better along the lines of, “Intervertebral spacing suggests a high neutral posture and broad range of motion in the necks of sauropod dinosaurs” or something like that.
Feb 2015: My second-longest title ever! Looking at it now, I think we could have titled it, “Effects of intervertebral cartilage on neck posture and range of motion in sauropod dinosaurs” and gotten it down to 14 words, but the word ‘neutral’ is doing real work in the original so maybe that’s a bust.

Mike: UGH, rubbish.

[October Matt is up by three points at least]

Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus. (12 words)

OK
Oct 2014: Along the same lines as the previous: “Caudal pneumaticity and pneumatic hiatuses show that pulmonary diverticula in the tails of sauropod dinosaurs were pervasive and complex” or something.
Feb 2015: Good. Long only by comparison with some of my earlier titles. Does what it says.

Mike: NOT GOOD ENOUGH

The neck of Barosaurus was not only longer but also wider than those of Diplodocus and other diplodocines. (18 words)

GOOD
Feb 2015: My second sentence-as-title, and another entry in the run of mostly long titles from 2012 onward. I like how precise it is, despite the length.

Mike: GOOD

A ceratopsian dinosaur from the Lower Cretaceous of Western North America, and the biogeography of Neoceratopsia. (16 words)

GOOD
Feb 2015: I had no say in this one (by choice, I’m sure Andy et al. would have listened if I had had any suggestions about the title, but I didn’t). If I could rewrite it, I’d probably make it even longer by adding in the word ‘new’ between A and ceratopsian

Haplocanthosaurus (Saurischia: Sauropoda) from the lower Morrison Formation (Upper Jurassic) near Snowmass, Colorado. (13 words)

OK
Feb 2015: Feels a lot longer than its 13 words, mostly because so many of the words are polysyllabic. Normally I like pulling the words in parentheses out, but in this case I can’t see that doing that would actually improve the title. Sometimes descriptive papers need plain titles. It’s okay.

* * * * * * * * * * * *

Lessons

First, Mike graded harder than I did. In fact, I only rated one of my titles as BAD, which seems a bit feeble. I think we were using different criteria. If a title was boring but serviceable, I gave it an OK, whereas Mike tended to flag any suboptimal title as RUBBISH. But I didn’t remember that about his post, and I deliberately avoided looking at it until I’d made my evaluations.

Second, except for the two PaleoBios papers, all of the titles from the first half of my career (2000-2007) are 12 words or fewer, including a substantial bundle from before I’d read either The Camel’s Nose or Strunk & White. I’m sure that being a Cifelli student and then a Padian student had something to do with that; Rich and Kevin made me into the word choice and grammar pedant that I am today (my rhetorical excrescences on this site are my fault, not theirs).

Third, much to my surprise and consternation, my titles have gotten longer over time, not shorter. Partly that’s because my little corner of the science ecosystem is getting increasingly subdivided, so it’s hard for me to write a paper now with a title as broad as, “The evolution of vertebral pneumaticity in sauropod dinosaurs.” (Possibly a prod to keep seeking out new, more open horizons?) And I suppose there is some tension between brevity, informativeness, and precision. For example, saying in the title of a descriptive paper than a specimen is “from the Upper Jurassic Morrison Formation of [Location], [State or Country]” adds 11 words, but the title really does need those words. That could be a segue into a whole other discussion about descriptive versus analytical work, but that will be a topic for another time.

Ultimately, this has been a fun exercise and it’s made me more aware of how I title may papers. This is useful because I have some manuscripts in the works that deal with really detailed anatomy, and I need to figure out how to give them titles that are precise and informative but still punchy. It’s not easy.

Parting thought: after I posted the slides from my photography and illustration talk, Mike and I talked about posting some of our figures and dissecting them to see how they could be improved (it’s axiomatic that almost all figures could be improved in one way or another). We should really get started on that.