Sauropod necks (Re: DinoMorph Strikes Back!... or does it?)

[GSP1954@aol.com]

I visited Kent's website and the new paper in The Sauropods to check out his 
sauropod necks. 

Basically every sauropod Kent has restored has an essentially straight neck 
and dorsal series, with if anything a hang-dog droop. If Kent is correct then a 
wide array, perhaps all sauropods, living over much of the Mesozoic era and 
all the continents, very diverse in body form, some with short necks, some with 
medium necks, some with very, very long necks, some with low shoulders, some 
with high, all had pretty much the same low slung neck posture. Itâs not 
impossible, but itâs really odd. 

Now, Kent goes on a lot about the supposed motives and anatomical misdeeds of 
those who have and continue to restore some sauropods with erect, giraffe 
like necks. He likes to use the word artistic as in license a lot. That's not a 
big problem in of itself - but only if Kent is pretty much right. 

Kent is, in the main, spectacularly wrong. It is obvious looking at his own 
neck restorations, as well as fossils he cites. I therefore make a counter 
charge. In what appears to be an effort to homogenize all sauropod necks into 
straightdom, Kent as in some cases glaringly misarticulated vertebrae, and 
ignored 
or misrepresented key fossil evidence. He is taking artistic license to an 
extreme never dreamed of by others like myself. 

ZYGAPOPHYSES

The paper says that in some living animals the zygapophyses slide no further 
than when they remain 50% overlapping, in others until the overlap is only 
25%, and others go so far that they barely overlap, which makes sense because 
many joint surfaces are fully exploited from maximum extension to maximum 
flexion 
on a regular basis. In all cases taut joint capsules prevent further sliding, 
so even barely overlapping zygapophyses donât disarticulate. 

The question and problem is how far the zygapophyses slid in sauropods before 
they reach their limits. Just 50%? 25%? All the way to just a few percent? 
The answer is no one knows entirely, and probably no one ever can know. 
Sauropods are neither mammals or birds, and they are much larger than the 
latter. It 
is improbable that all sauropod zags could not disarticulate beyond 50% overlap 
since those of birds and mammals sometimes do. 25% overlap might be a 
conservative limit, but even that can be exceeded in some mammals. Stating that 
sauropods definitely could not exceed 50 or 25%, or did exceed 25%, is opinion 
rather than falsifable science because these alternatives are all plausible. So 
all we can do is articulate the cervo-dorsals with the zygapophyses at various 
overlaps, see what happens, and note they are all plausible alternatives. 
Sometimes there is only so much that one can do. 

Kent claims that giraffes can rotate each pair of cervicals more than 
sauropods. But sauropods have a lot more cervicals than giraffes. Since 
sauropods had 
so many more neck bones they did not have to have as much motion between each 
pair to get the same over all flexibility. It is true that some sauropods had 
shorter neck base zygapophyses than giraffes, this is true of at least some 
diplodocids. But other cases are less clear, and as far as I can tell Euhelopus 
had quite large zygapophyses (more on that below). Camarasaurus may have had 
fairly large zags, but it is hard to tell for sure with available specimens. 

GIRAFFE

Kentâs articulation of the neck base looks fine. For that particular 
specimen. In Solounias N 1999 J Zool. Lond. 247: 257 a giraffe neck base in 
exactly 
the same posture is clearly way out of neutral osteological articulation (NOA), 
because the anterior ball of 8 is pitched much more ventrally in Nickâs neck 
than in Kentâs neck. Well thatâs not good. When I restored Nickâs neck in 
NOA 
it came out subhorizontal. Same with a neck I articulated at the Smithsonian. 
This serves as a warning that osteology may not consistently record NOA. 
Perhaps its an age thing as I believe Kent has suggested (but I do not know the 
age 
of the Solounias neck). In any case dinosaurs did not tend to ossify as well 
as old mammals, so how do we know whether they are ossified enough to 
accurately record and compare the NOA? 

There is another problem. Kent implies that the steeply pitched up NOA he 
restores is âcharacteristicâ of giraffes. I take it he means that the NOA 
is the 
same as the neutral life posture (NLP) that the relaxed muscles, tendons and 
ligaments may favor. But is it? No documentation is provided. No one has 
actually determined the NLP in giraffes. Is it even the same, or does it differ 
between individuals? If it does differ, does the NLP consistently follow the 
NOA 
and vice versa, or are they inconsistent? No one knows. Is either the NOA or 
the NLP even important in the life of your average giraffe? I looked at a lot 
of giraffes in technical diagrams, photos, films and at the zoo and I have no 
idea what the NLP of a given individual, much less the species, is. They seem 
to do whatever they like with the neck whenever they damn well please. Seems 
like no one has told them about NOA/NLP. When walking the neck can be 
horizontal 
or vertical or someone in between. Same when feeding (as the paper notes), 
same when standing. So what the one example of a long necked giant herbivore 
tells us seems disturbingly ambiguous, which threatens the whole premise of the 
methodology. 

DIPLODOCUS

Funny thing is that I have never restored a diplodocid with an erect neck 
base, which Kent does not mention.

Kent restores the neck base vertebrae as being able to dorso-flex or elevate 
by 5 degrees when the zygapophyses overlap is reduced to 50%. But why stop 
there? If the overlap could have been reduced to just a few percent, just as 
good 
an alternative with the data we have and actually logical considering the 
shortness of the zygapophyses, then rotation would be somewhat greater. Not a 
whole lot greater, but thatâs not a problem when you have so many cervicals. 
Would have been better to show three alternatives at 50%, 25% and bare overlap 
and 
let the rest of us researchers see what is possible. 

APATOSAURUS

Big problems here. Really big. Kent has grossly disarticulated the vertebra 
of CM 3018 to keep the neck straight, rather than curved way, way DOWN. He has 
the zygagpophysis of all main cervicals 100% articulated, which is fine. In 
most the anterior ball of the centrum is fitted tight into the posterior socket 
of the preceeding centrum. That seems OK too. Centra 6 & 7 are, however, 
disarticulated to the point that the ball of 7 is completely out of the socket 
of 
6, leaving an all too visible gap between them. Gosh, I would think if anything 
is going to hurt it would be something like that. Doesnât Kent insist that 
all cervicals be completely articulated at all times? I don't think the problem 
is with the original figure of the vertebrae because on a photo of the 
straight neck on the CM mount (H McGinnis 1982 Carnegie's Dinosaurs) the ball 
is also 
out of the socket even though the zygapophyses are in a strongly dorso-flexed 
articulation. Also note that the gap between the cervical ribs of 6 & 7 is 
unusually large. But wait, there's more. The centra of 4 & 5, 11 & 12, and 12 & 
13 are also pulled out to a markedly greater degree than those of other 
cervicals, albeit less than that of 6 & 7. Kent's criteria for articulating the 
cervicals is highly inconsistent and in 4 cases violated basic anatomy, once 
outrageously. Conversely, while the centra of vert 17 & 18 are flat on, the 
zygapophysis appear to be pulled completely apart, another form of 
inconsistency that 
violates Kentâs own assertion that the zags MUST have at least some overlap. 
Viola, a nearly straight neck. 

Now, here's how to restore the actual NOA. Copy the original 3018 cervical 
lateral views at a large scale. Then carefully trace out each one - with 
emphasis on the articular surfaces (don't worry about the pneumatic struts etc) 
and 
include the complete cervical ribs - on a separate little piece of tracing 
paper. Don't start at the base of the neck and articulate them in series 
progressing anteriorly, that can bias the results. Instead pick a pair from 
somewhere 
in the middle of the series and carefully articulate them, trying to keep the 
zygapophysis fully articulated and the ball-and-sockets reasonably nice and 
tight, but not too tight. Put those down and do the same with another pair from 
somewhere else in the series. Continue doing pairs until they are all done and 
then start stringing the pairs together, attaching them randomly, until the 
neck is all done. Now, at this point if you are a drinking person you might 
want 
to quaff a few beers. Or maybe a trip to the paleotherapist is called for. Or 
perhaps a good laugh. For the joke is on all of us. 

For you see, when actually articulated in its NOA the cervical series of 3018 
takes a dive like a U-boat caught in the searchlight of a B-24 Liberator 
about to drop aerial depth charges on it. The neck, especially anteriorly, 
follows 
such a strong inverted U-curve that the anterior end points straight down, 
and the head is literally below ground level. The neck articulated by Kent will 
do this if the 4 disarticulated centra are pulled together so the balls fit 
fully in the socket. Which makes me wonder. 

Obviously no apatosaur went wandering about using its head as a plow. Ergo, 
at least some individuals normally carried their necks well above the NOA (we 
need to see what the articulation is like in other specimens). This required 
one of two things, or both. The zygapophysis were usually in a dorsally flexed 
position, rather than 100% articulated. This is very likely. Or, there was a 
good deal more cartilage spacing between the centra than we have been thinking. 
O
r, a combination of the two, in which each adjustment would have been less 
extreme. Ergo - unless there is something very wrong with the classic figures 
of 
the 3018 neck and this does not appear to be the case - then the NOA is not a 
reliable guide to normal neck posture in the long necked sauropods. Which is 
most annoying. What was the NLP of apatosaurs? Hang dog like Kent thinks? 
Higher as I restore? No one knows, since we cannot observe what the soft 
tissues 
were pre-stressed for. 

Why would apatosaurs have necks whose NOA put the head underground? It was 
not for catching gophers, they didn't exist back then. Feeding below water 
level 
while standing on the shore? The reason that does not work are too extensive 
to go into here. Diplodocids were adapted for adapting a tripodal, static 
feeding pose like giant slothes. No need for the neck to be able to elevate 
strongly dorsally when the dorsal series is already subvertical, but being able 
to 
reach forward of the erect body would be greatly expand the feeding range 
without having to go to the trouble of shifting position.  The ability to 
ventrally 
extend the neck so far forced the articulations to be biased in favor of that 
posture. Carrying the head above the ground when on all fours therefore 
required most or all articulations to be significantly dorso-flexed. And that 
is 
not a problem since the joints remain within normal articulation range. 

Kent also is displeased that I show the dorsals of Apatosaurus strongly 
arced, and implies that for some obscure reason I employed artistic license. I 
am 
so very, deeply ashamed. Well. Not really. All I did when I restored the 
skeleton of 3018 was to exactly trace out the preserved dorsals as figured in 
Gilmore and carefully line up the zygapophyses and centra facets, with space 
between 
each centra pair to allow for cartilage discs; its not my fault they describe 
an strong arch. Suppose I had decided the arch was too strong and tried to 
deliberately manipulate the dorsals in a lesser curve. Now what would that be 
called? Oh yes, artistic license. Even within horses back posture differs a 
lot, 
and its quite possible they did so in apatosaurs. Do I prefer arched backs in 
sauropods? Then why did I restore Barosaurus with a nearly straight dorsal 
series? Or mamenchisaurs? Oh, that's right, because it came out straight when I 
paper articulated the published vertebrae figures.   

DICRAEOSAURUS

Years ago I noted that dicraeosaurs could not strongly elevate the neck to 
the point they had a hang dog look. 

In this case it is every single centra facet that Kent restored flat to one 
another, with many zygapophyses pulled well out of 100% neutral articulation 
into a more extended, depressed position. So in Kent PaleoWorld the dicraeosaur 
neck is straight because the centra are flat on while zags are often out of 
neutral alignment, while in apatosaurs the neck is straight because the 
zygapophyses are always in full, neutral articulation while some centra are 
pulled 
apart. Maybe Itâs just me, but is this not gross inconsistency applied in 
whatever manner that happens to be needed to get the necks straight?  

Now, Kent says that a vertebrae are in neutral articulation when the 
zygapophyses overlap 100% and the centra are flat on. Well they should, but in 
Dicraeosaurus there are numerous cases where both the zygapophyses and centra 
between 
two vertebrae are not in neutral position at the same time. This is not good, 
because it means there is no determinable NOA. Is the Dicraeosaurus neck in 
NOA when all centra are flat on and the neck is straight but some zygapophyses 
are out of neutral as Kent shows, or when all zygapophyses are at 100% overlap 
and some centra are angled so the neck is more elevated into in a nice 
S-curve? No one knowâs, and probably no one ever will. 

What we can say is that the notion that dicraeosaurs walked about the 
Tendaguru landscape with their noses scrapping the ground as Kent shows just 
because 
thatâs when the centra are flat on violates common-sense. What large 
herbivore 
does that? Every once is awhile one has to do what is logical - and get the 
head up. 

EUHELOPUS

There are two cervo-dorsal series preserved articulated in what Kent calls a 
presumably nonlife death pose. He is correct that in the most complete series 
of vertebrae 16 - 18 are pitched up to the point that the two pairs of 
zygapophyses are dorso-flexed. However, neither set is anywhere close to the 
limit of 
articulation. In one the overlap is still 50%, very probably a lot more 
sliding to increase pitch up was possible. In the other the overlap is still 
something like 80%, lots more dorso-flexion was absolutely possible. Kent 
claims 
that the rest of the cervo-dorsal transition is strongly dorso-flexed. But this 
is not true according to the figures, which if they are accurate show all but 
one of the zygapophyses clearly set in full, neutral articulation. Is that why 
Kent says they are dorso-flexed but does not measure the angles in the figure 
like he did for the two cervo-dorsals that definitely are dorso-flexed? Most 
of the anterior dorsals are in a straight line. But 19 is clearly pitched up 
relative to 20 even though it is in NOA. 

And one articulation is the real kicker. It is plain as day that the 
zygapophyses between 18 & 19, far from being dorso-flexed, are obviously and 
significantly ventro-extended! This can be seen in both the lateral view that 
Kent 
reproduces, and even more obviously in the dorsal view in Wiman. Kent makes no 
mention of this in his discussion, nor marks it in his figures. My mind 
boggles. 
How could this be missed? 18 & 19 are ventro-extended to the point that the 
zygapophyses are 40% out of neutral overlap, worth about 8 degrees of 
depression 
(thatâs about 20 degrees below dorso-flexion when the zags are 25% 
articulated in the reverse direction!). In his straight posed version of the 
neck Kent 
left 18 & 19 dorso-flexed as in Wimanâs figure, so he lost 8 degrees of 
elevation that was actually present. When all the cervicals and anterior 
dorsals 
where in NOA I measure a dorsal pitch of about 30 degrees, somewhat less than 
preserved in the Wiman figure. 

So how can it be said that the neck was pulled back into a death pose beyond 
the limits possible in life when one pair of cervo-dorsals is actually 
extended ventrally, most others are in neutral posture (with most of the neck 
in a 
straight line rather than arced dorsally), and none are near their 
dorso-flexion 
limits? The answer is that one cannot say that. Only if the zygapophyses 
could not dorso-flex beyond 100% overlap would the neck be prevented from 
rising 
even further above horizontal, and as far as I know that just does not happen. 
Using the very same neck joint mobility criteria described in the paper the 
preserved neck is not close to itâs maximum limit of dorso-flexion. It could 
go 
a lot more vertical. How much? Well, when I, artistic fool that I am, restored 
the neck of Euhelopus in a vertical pose I was, darned good paleoartist that 
I actually am, careful to make sure that the zygapophyses all remained in 
articulation. There are no flaws in the series I restored. 

For, as I mentioned earlier the cervo-dorsals judging from Wimanâs figures 
have large zygapophyses, much bigger than in Diplodocus. If zag overlap is not 
allowed to go below 25% then I measure 17 degrees of dorso-flexion from NOA 
between 17 & 18, or 12% if only 50 degrees is allowed and thatâs probably too 
conservative. It appears that only 17 â 20 could dorso-flex so much. Kent 
says 
that the preserved flexion at the neck base is âsharp.â No it isnât. 
Itâs all 
a smooth, gentle curve. The degree of dorso-flexion between each cervo-dorsal 
needed to achieve the modest upslope of the preserved neck is quite small, 
just 5 degrees or so and thatâs nothing for these cervo-dorsals, being no 
more 
than Kent says was possible in Diplodocus assuming very conservative rotation. 
Even with the neck fully vertical to the ground the divergence between each 
neck base vertebra needs to be only around 10 degrees spread fairly equally 
over 
8 articulations, which still does not exceed the rotation allowed by the 
zygapophyses. I doubt vertical was the NLP, but it does not require the 
cervo-dorsals to even reach minimal zygapophysial overlap so there is no reason 
to think 
it was a difficult or uncomfortable posture that could not be assumed on a 
frequent basis. What is intriguing is that the anterior cervicals, which are 
preserved straight in neutral articulation, have lots of elevation left over 
and 
could be even more dorso-flexed than in my vertical necked restoration. 
Consider that there are about a dozen and half cervicals in Euhelopus, over 
twice as 
many as in a giraffe. Assume a very conservative 5 degree dorso-flexion 
between each pair. What does that add up to? 90 degrees total, and a vertical 
anterior neck. Since the cervicals could rotate substantially more then the 
neck 
could arc high over the back (see below on Mamenchisaurus), which as far as I 
know is further than in giraffes with just 8 (thatâs right, 8) cervicals. 

CAMARASAURUS

I have carefully and closely examined the articulated neck of CM 11338, which 
is dorso-flexed to the point that the distal neck is about 90 degrees 
relative to the anterior dorsal series. The zygapophyses of the cervo-dorsals - 
which 
seem substantially larger than those of Diplodocus but its hard to measure 
them - remain articulated. Some of the zygapophyses are near their maximum 
flexion and overlap only a little, none have slipped past the point of 
articulation. If anything the zags are probably a little less articulated than 
in life in 
the same neck pose because the vertebrae seem to have been pulled together 
some as the carcasse dried. The preserved pose certainly is well beyond NOA but 
so what, since Apatosaurus 3018 was walking around with many of its 
zygapophyses dorso-flexed well beyond NOA. Could live camarasaurs pitch the 
neck up until 
the zygapophyses were barely overlapping? Know one knows this either, but it 
is entirely plausible and there is no compelling evidence that they could not. 

Here's where things get really interesting. Kent claims that the fused 
cervo-dorsals of AMNH 5761 (cervicals 11 & 12, the last two in the neck) are 
critical to the issue, and that they are fused straight, and suggests you check 
them 
out at his website. These are from one of the Garden Park super camarasaurs, 
I've restored the skeleton and it was probably an old, massive beast of ~23 
tonnes. I agree that these bones are critical and also suggest you check out 
Kent's photos (and/or the technical drawing in Osborn and Mook 1921 AMNH Mem 3, 
which is identical). Just looking at the fused cervicals it is obvious they are 
not in a straight line. Instead they are clearly more flexed than the 5 degree 
dorso-flexed Diplodocus cervicals Kent illustrated. Kent says they lie flat 
on the table. No they donât, the posterior rim of 12 is clearly off the 
surface. More specifically it is clear of the soft mat the rest of the two 
bones are 
sinking into a little. Put the cervicals on a hard surface and they would 
rock. Also, the antero-ventral rib articulations of 11 project strongly 
ventrally 
and act as props. Knock off all the parapophyses (Iâm sure the AMNH 
collections manager wouldnât mind) and those cervicals would really rock, 
baby. The long 
axis of centrum 11 descends posteriorily towards the table a little, the long 
axis of centrum 12 descends anteriorily towards the table a little. Of course 
its always a tad iffy measuring the amorphous anatomical results of 
noncognitive evolutionary design, but it's just not possible to overlay the 
elements 
with a single line that follows the long axes of both centra at the same time. 
So run two lines along the long axis of each centra. I did it twice, one time 
the measurement of the dorsal flexion was 7 degrees, the other 8.  

But things get better still. Look at the zygapophyses. Tightly co-ossified, 
it appears that they are close to or at full, neutral articulation. In other 
words, this old suckerâs neck base vertebrae where dorso-flexed - thatâs 
dorso-flexed - when they where in neutral osteological articulation! (Similar 
to 19 
& 20 in Euhelopus) And they froze that way. What better osteological proof 
could there be that the neck base of camarasaurs were normally pitched upwards? 
This situation may be similar to giraffes, in which only some old adults ossify 
enough for the bones to accurately record the most common neck posture. Of 
course before the two vertebrae fused up they could have been dorso-flexed even 
further. Now, Kent reproduces the old restoration of 5761 by Osborn and Mook 
with the depressed neck and says this is the correct NLP. Yeah, right. In that 
figure there are no neck base vertebrae that even look like the fused 11 & 12, 
instead they bones as drawn are rather schematic, separated and posed in a 
straight line in order to get the depressed neck. Itâs artistic license; it 
is 
not possible to place the fused elements into the O&M illustration and get the 
same depressed neck pose. And it is just wrong. Insert the two dorso-flexed 
vertebrae as they are actually preserved, and give other cervo-dorsals the same 
dorsal rotation, and the neck must be pitched up. How much? The 7 or 8 degrees 
frozen in the two vertebrae may not sound like much. But we just saw how in 
Euhelopus a little adds up to a lot in necks with many vertebrae. Same here.  

So back to the 11338 neck. At first glance it may look like the neck base is 
strongly kinked upwards. But take a closer look. Just as with Euhelopus at no 
point is there a strong dorso-flexion between any two vertebrae, nor is any 
particular vertebra kinked, its all a smooth, gradual curve. The number of 
degrees between cervical 8 and dorsal 3 is about 60. The average amount of 
flexion 
needed to achieve a 60 degree flexion with 7 joints is about 8.5 degrees 
between each two vertebrae, which is the approximate degree of flexion present 
between all the cervo-dorsals. The flexion at the 12 joints needed to achieve 
90 
degrees is only 7.5 degrees per joint. That being because neck flexion in long 
necked animals with many cervicals is achieved as surprisingly incremental 
alterations at each point add up to a strong divergence when the end is 
reached, 
just like in evolution. 

It seems that the degree of dorso-flexion with the cervo-dorsals in NOA is a 
little greater in 5761 than in 11338. Thatâs not surprising, since animals 
are 
not precision manufactured machines. As we already saw with giraffes, thereâs 
a lot of slop in natural systems. 

If Camarasaurus really had the horizontal or drooping neck restored by Kent 
then the two vertebrae would have fused either truly straight, or even arced a 
little downwards, as they are posed in that old, inaccurate, droop necked 
Camarasaurus restoration. But exactly the opposite is true. So, rather than 
being 
evidence of a straight neck, the fusion of the posterior cervicals of 5761 to 
nearly the same degree of dorso-flexion present in the same vertebrae of 
vertical necked 11338 shows that the flexion of the latter's neck base is no 
where 
so extreme that it is beyond the plausible position in life, rather it is only 
a little beyond that which the vertebrae of the old individual fused into. Of 
course the vertebrae would not have frozen in the most extreme dorsal-flexion 
position because that could have hindered drinking. In fact, because the old 
sauropod needed to lower the neck to drink, the fact that it's neck base 
vertebrae fused with almost as much upwards flexion as is present in the most 
vertically articulated necks strongly confirms that a the neck was normally 
carried 
well above horizontal. So with Camarasaurus there is no speculation, we have 
direct fossil evidence that the neck was normally pitched strongly dorsally, 
although the most vertical possible posture was probably used only when needed. 
Of course my juvenile and adult Camarasaurus skeletons are restored with 
exactly the neck base flexion preserved in these specimens. That includes 5761, 
in 
which the fused cervo-dorsals are carefully reproduced:). 

What I wonder is why were the all-critical cervicals of 5761 not included in 
the paper? Of course had they been figured it would have been clear as day 
that they are pitched upwards, and the basic thesis of the paper would have 
collapsed like the sagging neck and dorsal series in a broken down old, sway 
backed 
horse. Instead the cervicals are posted only on the website, where they are 
said to be straight even though they are all too obviously not so. 

There is additional evidence that an erect neck base is not abnormal in 
Camarasaurus. In 11338 the cervical ribs are splayed ventrally a little. This 
indicates that the neck was elevated a little above the neutral posture so the 
ribs 
sprung out when the carcasse rotted, not surprising since the necks are 
preserved at their maximum extreme vertical reach. But the splaying is at most 
only 
a few degrees, if the neck was pulled far dorsal to neutral posture then the 
rib splaying should be greater. Equally important, the posterior cervical ribs 
almost, or do, contact one another at the anterior end of each rib even 
though the rib shafts are straight, rather than bent. This too supports the 
neck 
base of 11338 not being far above its normal dorsal flexion. 

One commentator flippantly said that the dorso-flexion of the tail of 11338 
is evidence that the neck also is hyperflexed into a nonlife pose. But while 
the neck is well articulated, it appears that the tail base is badly 
disarticulated, with some centra pulled far from one another. 

MAMENCHISAURUS

It looks like Kent failed to articulate the zygapophyses in some of the 
anterior dorsals of M. youngi 0083 together, in one case to the point that the 
centra faces are not lined up. Again itâs quite obvious. Kent compares the 
neck of 
0083 to my restoration of the neck of M. hochuanensis IVPP 3, which is not 
really kosher since they are different taxa. He also seems to fail to 
understand 
that I do not alter the shape of vertebrae when I carefully trace out each 
bone in skeletal restorations. When neck base vertebrae are posed dorso-flexed 
it automatically creates the visual impression that they are wedge-shaped.  

Kent as usual dismisses the quarry map of M. youngi 0083 as a death pose. 
Note that again there is no sharp juncture at the neck base, it is a long, 
continuous curve with each of the 19(!) or so cervicals and anterior dorsals 
dorso-flexed just a few degrees until the head is high over the back, not 
surprising 
for such a very long necked beast with so many cervicals. To look at it 
another way, if each cervical and anterior dorsal is dorsally elevated just 5 
degrees that's 95 degrees of total rotation. Again no evidence this was not 
possible 
in life, it does not overflex the zygapophyses. Despite the very good figures 
of the cervicals the zags are a little murky and its hard to judge how big 
they are, but they seem larger than in Diplodocus. Since sauropod cervicals 
seem 
to have been able to dorso-flex well over 5 degrees, it is quite possible 
that even greater elevation was possible in life, so the death pose is not a 
nonlife pose. 

What is odd is that, even though the paper acknowledges herbivores often feed 
with the neck well out of its NOA, there is no attempt to restore 
mamenchisaur necks in their maximum elevation. Even assuming Kentâs probably 
excessively 
conservative methods, that would be quite high, even if the neck is just at 45 
degrees. Of course, that would be pretty close to the way I restored the neck 
in my skeletal restoration, and that might not look good.  

What is really interesting. or peculiar, about M. youngi as found is that the 
tail is strongly dorso-flexed. In the skeletal mount the tail base is 
"corrected" so that it is straight. And all the zygapophyses are pulled way 
apart. 
You might think a certain someone had a hand in that. Seriously, when I 
articulated those beautifully preserved suckers I had no choice but to position 
them 
in exactly the same position as in the quarry. So the death pose is the life 
pose, with the tail pitched up at a sharp angle, an exaggeration of the slight 
upwards arc of most sauropod tails. Probably a display thing.  As an artist I 
don't like it, looks dorky. Too bad. 

BRACHIOSAURUS

Kent spends much time going on about how absurd it is to restore this 
shoulder high dinosaur with an erect neck when the entire top half of the neck 
base 
is not even preserved! Who knows how little or big the zygapophyses were. 
Unless better specimens show otherwise â and donât hold your breath on that 
- 
there is no reason to conclude the neck could not be raised to vertical, which 
as 
usual requires not some sharp kink between just 2 or 4 cervo-dorsals, a long 
gentle arc of many cervo-dorsals the type I've been restoring lo these 25 years 
will do the job quite nicely. 

Itâs yet another head scratcher that in a dinomorph figure Kent shows 
Apatosaurus and Diplodocus with their heads at what he restores at their 
maximum 
vertical reach, which is not very high, but shows Brachiosaurus at only its 
NOA, 
which is not much higher. Thatâs comparing apples and oranges. Why not show 
the 
brachiosaurâs neck in a more elevated position, say 45 degrees which would 
seem to be no problem even assuming Kentâs very conservative rotation arcs? 
Would it be because even that would show itâs head very high, at like 10-12 
m? 
(Max vertical reach is about 14 m.) Would not do much for the scenario of 
sauropod as not being super high browsers, would it? Hmmm.  

Kent also brings up the dorsal arc again. And again I did what I could with 
the incomplete dorsal series of B. brancai. Even if the dorsals of the B. 
altithorax type were straighter that does not establish what was going on in 
brancai. Aside from possible individual variation, they are not the same 
species, 
may even be distinct genera. 


So much for the sauropod taxa. We do not really know what the NOA or NLP is 
even in giraffes, or if there even is a consistent NOA or NLP. NOA is, it 
seems, not a reliable indicator of NLP in long necked animals. When correctly 
articulated, and as directly preserved in one old camarasaur, sauropod neck 
posture 
appears to be diverse, as is the group they belong to. Short armed 
diplodocids had horizontal necks, with at least dicraeosaurs going around with 
the head 
not above shoulder level, the longer necked forms' normal nonfeeding posture 
is unknown. High browsing was achieved tripodally, in which the ability to 
depress the neck forward was exploited. As far as is known longer armed 
sauropods 
were able to elevate the neck at very steep angels, if not close to or 
vertically, and at least some cases perhaps beyond. It has yet to be shown that 
any 
nondiplodocid could not raise the neck far above the shoulders. In Camarasaurus 
normal neck posture was well above horizontal judging from the dorsal flexion 
of cervo-dorsals that fused pitched upwards in an old individual despite its 
need to drink. It was the need to lower the head that led to the zygapophyses 
being neutral when the neck was below the normal, erect posture, in which the 
articulations were dorso-flexed. However, exact NLP is not known and probably 
unknowable. Without hard data to go on I like to think the neck was frequently 
carried at 45 degrees or a little above rather than the used-when-needed 
vertical pose. It's the artist in me. In skeletal drawings people have been 
restoring dinosaur tails as sweeping this way and that for many years, rather 
than 
strict NOA. No need for there to be a law that the neck or tail must be in its 
exact NOA, or anywhere close to it, as long as the series is within its 
plausible range. So I declare Paulâs Law, which declares researchers, artists 
and 
preparators free to pose vertebral columns in any anatomically plausible 
posture 
they choose. This is opposed to Kentâs Law which demands obsessive conformity 
with NOA even if that dives the head into the ground. After all, it is quite 
possible that even if it was above its NLP, much less NOA, that Mamenchisaurus 
often carried its neck vertical, to get a better view. All the better to see 
those tasty trees in the distance. And nasty predators. Since giraffes don't 
seem to pay all that much attention to NLP, perhaps we should not obsess about 
it either. Besides - and you can call me a quirky artist on this one - it just 
does not seem right to draw Apatosaurus with its head in the ground. Or 
Dicraeosaurus scooting along with its nose almost scraping terra-firma. 

It cannot be overemphasized that Kentâs work is, in part by ignoring his own 
conclusions as to cervical joint function, creating a very misleading 
impression of sauropods that leads to further misconceptions about their 
internal 
biology. According to Kentâs own research all necks can be dorso-flexed well 
beyond the NOA of the zygapophyses and centra, he cites no exceptions. This 
means 
that there is no anatomical reason to doubt that all long necked sauropods with 
fairly high shoulders â brachiosaurs, mamenchisaurs, omeisaurs, euhelopids, 
giant titanosaurs and so on â could pitch their necks up steeply and elevate 
their heads many meters above heart level when quadrupedal, even if a 
conservative 25% zygapophyses overlap minimum is assumed, thereby achieving 
heart to 
brain height differentials many times greater than in giraffes. This 
anatomically 
verified ability to elevate the head so far above the heart, in some case by 
8 to perhaps 10 m, refutes arguments that cardio-vascular concerns forced them 
to keep their heads close to heart level. If the hypothesis that sauropods 
could not pump blood up to high held brains were true then the ability to raise 
the head well above heart level would be positively dangerous. Imagine long 
necked, 10-100 tonne beasts having nothing in their neck design to prevent them 
from easily raising their heads too far above heart level â just a couple of 
meters according to the inadequate pressure hypothesis - misjudging when their 
little brains will run out of oxygen, getting whoozy and occasionally keeling 
over, only recovering and getting up - if not seriously injured - when cranial 
blood flow is restored. Would make sauropod life difficult to say the least. 
In fact itâs selectively ludicrous. If sauropods could not elevate their 
heads 
higher above the heart than giraffes for circulatory reasons then there would 
have been absolute anatomical adaptations to limit neck elevation in the long 
necked examples if it risked brain shut down. The zygapophyses and centra 
would reach their dorso-flexed limit (well past NOA) when the neck was just a 
little above horizontal. Long sauropod necks would either be preserved in a 
rigid, near horizontal line relative to the dorsal series, or if pulled back 
post-mortem the zygapophyses would be truly disarticulated by over 
dorso-flexion 
until their facets were no longer in articulation at all, or the centra were 
pulled way apart, or both. That sauropods could have had such adaptations if 
they 
needed to have them is proven by the fact that dicraeosaur neck joints were at 
their dorso-flexion maximum when the neck was a little above horizontal, so 
it could not rise further. That in reality just a few degrees of dorsal 
rotation between the numerous cervicals of the long necked nondiplodocids 
allowed 
them to raise their heads far above their hearts, and probably high over their 
backs, required them to be able to reliably get sufficient blood up there on a 
constant basis one way or another. Probably via oversized hearts producing high 
BPs. Sorry all you cardio-pessimists. Of course long necked sauropods 
definitely were often feeding high in the crowns of trees, which makes a good 
deal of 
sense for long necked herbivores when you think about it. It is interesting 
that no sauropod is known to have been able to be able to elevate the head 
higher than about 15 m. That is probably the height limit of land animals, 
probably set by the hydrostatic pressure in the feet. 

Now some procedural complaints. There is a serious problem with a paper 
including so many and such obvious gross disarticulations, and so many 
inconsistent 
methods of articulation, and so many omissions, getting published in the 
technical literature. I donât know how this happened, something failed in the 
process. Why would anyone publish such easy to see disarticulations? I just do 
not 
get it. How the ventro-extended Euhelopus cervo-dorsals illustrated in 
multiple views could have been missed is beyond me. Canât people look at the 
blasted 
figures and see there is a big problem? What about the keypoint that even 
Kentâs conservative cervical rotation arcs clearly allowed many sauropods to 
pitch their necks steeply upwards? And what about those marvelous 5761 
cervo-dorsals, known for a century and proof positive that camarasaur neck 
bases were 
dorso-flexed like an old giraffeâs. Why are they absent from the paper? 
Dinosaur 
paleontology is not advanced by this sort of study. There are clear problems 
with the peer review system in paleo, which remains overly political to the 
point that obviously flawed work is being given a pass. And I do not like 
having 
my technical work spuriously criticized. I was not sent the manuscript before 
publication. Cannot complain too much about that since I do not always run by 
papers past those whose research Iâm criticizing. However, the paper uses 
some 
of my illustrations without, as I recall, prior permission, and if I was 
asked Iâm not mentioned in the acknowledgements. Could be copyright issues 
there. 

G Paul