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Futalognkosaurus dukei

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Futalognkosaurus dukei, a Cretaceous lognkosaurian titanosaur from South America.
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Algoroth's avatar
The eye of Algoroth is upon you! The upper arms, in my opinion, need some fleshing out. Nima, IMO, is right about the belly. IF that is a full-grown azhdarkid back there, the Futalognlosaurus looks too small. IMO? Beef him up!
palaeozoologist's avatar
Well, at least some azhdarchids reached giraffe-like heights, and Futalognksaurus was not as big as reported in the initial description and media reports.

I'm not sure which part about the belly you think Nima is right on. I will say this, the paper suggests that the torso is fairly short and compact in length, but probably wide. Belly depth is completely conjectural as we have no sauropod mummies to go from.

I am not particularly happy with this life restoration, but as my skeletal is out of date, I'm not going to do a new life restoration until a revised skeletal is attempted.
EmperorDinobot's avatar
Guys, just pretend it just came out of the egg. But the refs check out. Calvo et. al. is always shifty.
palaeozoologist's avatar
EmperorDinobot's avatar
Srsly. I agree with that it should be fatter. Dolphins are light. Whales are super fat. Think about that. This looks like a hatchling. Bigger=fatter. I can't imagine a 40 meter long dinosaur being incredibly gracile. It's just not a blueprint for life ATM.
palaeozoologist's avatar
Yes, but do whales LOOK fat in side view? I would say no, they look very aerodynamic and streamlined. Even the Blue Whale, the largest whale, does not "look" fat in side view, IMO. The only time a blue whale looks truly "fat" is when a female is pregnant or when it is gulping a huge amount of water to strain out krill and other small creatures; when this happens, the skin on the lower jaw expands enormously. But otherwise, whales tend to look very sleek. Obviously, sauropods aren't whales and I'm not suggesting we should restore sauropods based on whales. However, it does illustrate the point that in general, the largest animals are comparatively slim and trim and not 'fat' looking. This makes sense because of scaling issues as animals get really big: in order to compensate for the magnitude of their size, they have to become proportionally leaner than their smaller relatives.

"Bigger" is a relative term, so it depends on your definition of "bigger" if you want 'bigger' to equal 'fatter'. For instance, "longer" does not necessarily equal "heavier", you have to take in the other two spacial dimensions to be sure. For instance, Diplodocus has a normally cited length of 25 meters and about 11-12 tonnes. But Giraffatitan was about 22-23 meters in the best known specimen HMN SII, which massed probably around 30 tonnes. So while that specimen of Giraffatitan was shorter than Diplodocus, it was almost three times heavier.

And Futalognkosaurus was not 40 meters long; by my estimation--combining the information in the published papers and a published abstract--it was around 26 meters long.

Another thing: a dark secret of paleontology is that no one really knows how "wide" or fat any sauropod was, since nobody has done any real research on this, see paleontologist Mike Taylor's take on this here.
EmperorDinobot's avatar
Good point. I'm still contaminated by the view of sauropods with large thoraxes.
LittleRave's avatar
Neat!
The legs look kinda thin though, especially the upper parts. I think he needs some stronger muscles ;)
palaeozoologist's avatar
Thanks!

Generally, sauropod dinosaurs had (comparatively) lightly muscled limbs. However, I do show large muscles actually bulging from the scapulacoracoid region. I get this criticism somewhat often on my sauropods though, so you may be right. Thanks for the compliment and the critique.
LittleRave's avatar
Well, I'm just a layperson when it comes to dinosaur's anatomy and I guess you have a much larger knowledge about it, so I won't say there's something wrong with you depiction ... It just seems to me like such a large creature needs stronger muscles ;)
palaeozoologist's avatar
Well I'd consider myself a laymen also, and I wouldn't say I have a much larger knowledge. However I have read enough popular books on the subject to know that what an animal "needs" to function has to be determined by osteology.

Sauropod limb joints indicate their limbs were kept rather straight, which implies that the limb bones are mainly loaded in compression and that bending and torsional moments are significantly reduced which reduces the amount of musculature needed to support the animal. Also, limb muscle scars in sauropod limb bones are not that large, implying that they were not doing lots of rigorous locomotory behavior. However, they are in need of of strong muscles at the shoulder and hip since their limbs move basically like an inverted pendulum (I have depicted here rather large deltopectoral muscles in my restoration).

Also, the olecranon (basically a bump on the bone right behind the elbow) in sauropods is extremely small. Only some titanosaurs had a (somewhat) larger process. This indicates that sauropods had rather weak elbows and again implies limited amount of strenuous locomotion.

Finally, the phalanges are strongly reduced in sauropods, and are sometimes completely absent, so that in some cases only the metacarpals are left. This means the finger bones were extremely reduced and indicates that the forelimb was primarily used for the support of mass and that its use in propulsion was rather insignificant.

Therefore, all things considered, sauropods limbs were rather columnar, and because their limb bones were quite strong, they only needed limited muscle attachments. Hence, I draw my sauropods with very lean muscles distally but with stronger muscles proximally.

That's probably more than you wanted to know though, sorry. I tend to ramble on. Just thought you might be interested. :)
Algoroth's avatar
Elephants have columnar legs, which they bend, it seems, as few times as possible, but their legs have some very apparent musculature. While it seems logical that the larger the sauropods got, the leaner they would have to be to conserve weight, it seldom works out that way for non-gracile animals. Giraffes seem to me to be an exception, except that giraffes are rather gracile and built to run. Even so, look at the upper limbs of any even fair sized quadrupedal vertebrate.

Take the Namib desert elephants. They are very tall, with long legs, maybe more so than the normal bush elephant, but though they are rather elegant and slim, they don't look starved or mummified.

Muscles stretch out and thin down when extended, right? Depends on the muscle.
Bend your elbow to touch your nose and your biceps expands, even if one is skinny as a rail. Maybe not much, but a bulge appears. Let the same arm hang and the biceps thins down, but the triceps bulges. Try it and see. So, unless sauropods had neither triceps nor biceps, one might expect some bulging in the middling areas of the arms and the upper areas of the forearms, near the elbows.

The only instances I know of where the joints are larger than the shank of the bones is in birds, in the lower limb elements, and gracile quadrupeds, like dogs and horses. The upper limbs usually are thicker, unless there is a very bad arthritic condition.

I'm simply going by what I see in the actual world, fantasy artist though I am. The idea that such immense colossi would need only the minimum musculature to get through their day-to-day lives is a dubious one, at best.

Let us imagine that the limbs of an argentinosaurus could support, all by themselves, four times the animal's weight, without the muscles. All well and good, right? Not really. I used to have a bookshelf that held probably two to three hundred pounds worth of books, probably five to seven times its weight. A friend tried to move it with the books still on it and almost collapsed the unit. Obviously, a bookshelf is not designed to move by itself, but the addition of movement perpendicular to its face/front added stresses one might normally think would be well within its design limits to hold.

If a titanosaur is moving at two miles per hour and has to make a sudden turn, what kind of stresses do you think its legs/joints have to bear? I don't know the math, but it's a fair amount more than if it was standing still or moving forward in a straight line. What if it slips in some mud and has to maneuver to keep from falling? The stresses are enormous compared to straight line loads and standing still. Don't believe me? Try and walk on some ice some time.

This is day-to-day living, day in and day out, which means the minimum allowable strengths are not nearly enough. Do muscles have to bulge enormously to be strong? No. But, they do stretch and bulge when doing their jobs and it is this aspect I'd love to see reflected in your art.

What proofs have I? Use your Mark One eyeballs and look at both people and animals going about their daily lives.

No need to change anything on my account, but I just felt like airing my thoughts.
palaeozoologist's avatar
I agree with your observations (to a point). Remember though, that most of my drawins have fairly straight limbs. In this drawing in particular your observations only apply to the flexed right forelimb. I could show the muscles bulging more, so your right and I agree.

On the other hand, I think the four limbs of a sauropod could hold up its weight and have relatively light musculature. Why? Well, sauropods had big lungs and pneumatic vertebrae, so were quite light for their overall size. Also, the limbs were not pneumatic but solid, so were apparently quite strong. Also, they had lots of articular cartilage which would help cushion the bones both as they moved and as they stood still.

Also, I doubt sauropods were making too many sudden moves. Their limbs apparently weren't wired to their brain too well.

Maybe my view is too simplistic, but you have definitely given me some things I need to mull over and possibly change in my restorations in the future, so thanks :)
Algoroth's avatar
Quote: "Also, I doubt sauropods were making too many sudden moves. Their limbs apparently weren't wired to their brain too well."

All the more reason to have as much muscle as possible, not the absolute minimum. Why? Lack of fine coordination will mean they get into sticky situations more often.

The "sudden" moves I hinted at need not be fast to wreck the animal. I've been injured in my feet and legs and had to walk miles. My movements are often by necessity slow. The weaker my muscles, the more likely I will fall. Muscle workouts mean greater size, when the nutrition and a chance to rest are available. Not that these colossi would grow into sauropod bodybuilders, but I'd bet they'd be bigger than starving animals or mummies. As I said, minimizing everything in such colossi as brachiosaurs, titanosaurs, and apatosaurs would likely lead to their ruin.

My opinion, anyway.

The "Popeye" effect on the flexed arm looks good. I love the effect in cartoons--look at Disney's "brother Bear"--, but I've seldom seen anything like it in a terrestrial vertebrate, pictures or live animals. If you know of such pics, send me the links, because I love the effect and want an excuse to put it in my realistic art. I've seen the effect fairly often in limb walkers (chameleons) and brachiators, like monkeys and apes. Not at all impossible, but unlikely for Futalognkosaurus. No need to change anything on my account: I love your stuff!
palaeozoologist's avatar
Well, I'm not advocating giving dinosaurs the minimum amount of muscle. I guess I don't feel my restorations look anorexic or emaciated or undernourished in regards to the limb muscles.

Lean muscle can be strong without having to be large and bulky, so while I agree that bare minimum muscle would be disastrous, I don't think that's how I've restored it. I think sauropods probably had lean, but strong, limb muscles.

I guess I disagree that fine muscle coordination would lead to "sticky" situations more often. Why? Well, when I say they lacked coordination, I mean complex movements like we see that elephants do. Whether they are softly nudging a calf or are in a circus doing complex movements. Sauropods probably could not do those things. Do I think they were clumsy? By no means. To me, lack of fine coordination does not imply clumsiness anymore than someone not being a ballet dancer dooms them to a life of clumsiness.

Sorry, I don't know of the "Popeye" effect in any animals.
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LittleRave's avatar
That's what I meant ... I've never read books about dinosaur's anatomy, so I have no scientific knowledge ;)
Everything you explained sounds very logical to me though
Paleo-King's avatar
Naah, the legs are fine. It's that tiny torso that needs some growth - in just about every direction. The stiff-as-a-rail tail looks a bit too extreme as well... most sauropod tails and sacrals didn't align in a straight line with their dorsal column... just my two cents ;)
palaeozoologist's avatar
Nima, Nima, Nima...as I have repeatedly said, the torso of Futalognkosaurus appears to be very short anteroposteriorally. No measurements are listed for the dorsal ribs so the depth of the belly is conjectural, but appears reasonable since generally the dorsal ribs don't go much past the pubis (going off of other skeletal reconstructions of sauropods done by others), which, if you look at my skeletal, is what I have done.

And just because the tailing isn't portrayed as flexing all over the place here doesn't mean the tail was "stiff".

Actually the posterior dorsals and anterior-most caudal did articulate basically straight on with the sacrum, and as for what the rest of the tail did it depends on the sauropod. Since only one caudal is preserved for Futalognkosaurus, I think this is a reasonable interpretation.
Paleo-King's avatar
How many of those reconstruction are of Futalognkosaurus or other titanosaurs? Not too many I'm guessing... ;) Furthermore, the belly is deeper than just the ribs, it's a LOT deeper than the posterior ribs that are just in front of the pubis.
As for the tail--- I've never seen a tail in PERFECT alignment with the curve of the sacral centra. They curve, they are not completely straight. This is true in diplodocids, brachiosaurs and every sauropod I know of. The curve of the back changes slightly at the sacrum or the base of the tail - on other words no sauropod's "line of spine" is perfectly horizontal at the tail-hips junction. Many species have either a rise or a dip. Most macronarians have a dip. Yours is a perfectly straight line, this is far more geometric than organic. It even has a perfectly horizontal dorsal line that looks exactly as if drawn with a ruler, a total lack of curvature which isn't found in the spine of any known animal, let alone any sauropod. That's what I meant by 'stiff'. 8-)

In addition, the sacrum itself is curved. Take a good look at the SV-POW photos, there is a ventral "down-bulge" in the posterior sacral centra. The 6th sacral however levels off and does not continue the downcurve - so the 1st caudal must begin an upcurve, at least relative to the sacrum, at the base of the tail.

What we really need is a good lateral-view photo of the hips. A dorsal view photo would be nice too, though the dorsal appearance can be approximated from other titanosaurs' hips. Look at my new Mk-IV version for an example. The biggest problem is a lack of lateral view photos for the dorsals. The anterior ones were short but the posterior ones were probably of normal length or longer (this will be factored into upcoming versions of my skeletal). I doubt the torso was super-compressed. But again we need more pictures.
palaeozoologist's avatar
Several of the reconstructions are of titanosaurs, most notably the skeletal of Alamosaurus in Lehman and Coulson (2002). If you have that paper, the anterior caudals articulate basically in a straight line. The difference between that skeletal and mine is that the whole vertebral column is at an angle upward, whereas in my skeletal of Futalognkosaurus I do not portray the dorsal series and sacrum as being at a positive angle from horizontal. Note that I am talking about the articular surfaces between the centra, not the difference in neural spine height which in Alamosaurus shows a more "organic" configuration (i.e., not straight) which is due to the varying heights of the neural spines in the caudals.

It is possible that the caudal vertebrae shifted in height similarly in Futalognkosaurus but it is also possible that they didn't. For the present, my interpretation is reasonable in light of current information.

Because I only draw one caudal, you can't say that my caudals would have to be in "perfect alignment" for the shape of the outline of my restored tail to occur.

It is true that most sauropods have a change in the height along their dorsal series, but this is not always the case.

By the way, most shapes in nature are modeled by something called fractal geometry, so you dichotomy between "organic" shapes and "geometric" is false.

A lack of curvature is not synonymous with 'stiff' but is synonymous with 'straight'; just because I restore the top part of the tail with a more-or-less straight outline does not mean the tail was stiff. The terms are not synonymous.

I don't think that the sacrum is 'curved' after looking at the photos. Even if it was, a curvature on the ventral side of the sacrum doesn't really tell us what was going on the dorsal side, and as such it is an irrelevant observation even if true. The last sacral does not show (to me) any obvious up-curve relative to the sacrum from the photo. Even if there was, this could possibly be a taphonomic artifact, not necessarily indicative of the true osteology of the vertebrae as almost all the sacrums I have seen are at least somewhat distorted due to taphonomic processes.

I agree that we need good lateral and dorsal views of the hips and the dorsals to be certain as regards articulations and overall shapes. Until then, any additional squabbling over the details is irrelevant since we don't have the available data.

As regards the dorsals, the paper says that their functional length decreases from the anterior dorsals to the posterior dorsals. How many times do I have to repeat that? From the paper (p. 519), "The ten articulated dorsal vertebrae are partially prepared, all being opisthocoelous (Fig.14). The most anterior dorsal has an elongated centrum and the second is 2/3 the length of the first. The centrum length gradually reduces in the more posterior elements of the sequence, with the first one being 43cm long and the last one 28cm (without considering the anterior ball). This pattern contrasts strongly with the cervical sequence of this species, where the length increases until the middle elements and then decreases slightly posteriorly."--Emphasis added.

So, the vertebrae reduces from the anterior dorsals to the posterior dorsals, with the first being 43 cm, and the last being 28 cm. I think that is clear, and suggests that the torso was anteroposteriorly short (and if that is how you define 'compressed', then yes, it was indeed 'compressed'. Note however that it was very fat transversely). So if the first is 43 cm, the second is 2/3 or that (or 2/3*43=28.667... cm) and the last is 28 cm, then from the second dorsal to the last dorsal there is only a ~0.667 cm difference which is indeed a gradual shortening of the dorsals going posteriorly. I don't see how you can 'doubt' that--it's pretty clear to me--unless you think the authors were talking out of their you-know-whats.

Refs--

Lehman, T.M. and Coulson, A.B. A juvenile specimen of the sauropod dinosaur Alamosaurus sanjuanensis from the Upper Cretaceous of Big Bend National Park, Texas. J. Paleont., 76(1), 2002, pp. 156–172.

Calvo, J.O., Porfiri, J.D., Gonzalez-Riga, B.J., and Kellner, A.W.A. 2008. Anatomy of Futalognkosaurus dukei Calvo, Porfiri, Gonzalez-Riga & Kellner, 2007 (Dinosauria, Titanosauridae) from the Neuquen Group (Late Cretaceous), Patagonia, Argentina. Arquivos do Museu Nacional, Rio de Janeiro 65(4):511-526.
Paleo-King's avatar
I don't buy the weird measurements in Calvo, et. al. For one thing, Lognkosaurs (from what we know of them) had very compressed anterior dorsals and longer posterior dorsals. This is true in Malawisaurus, and in Mendozasaurus the anterior dorsal is also very flat (I doubt the postrior dorsals were that flat but they haven't been recovered). Ruyangosaurus (which may be a lognkosaur) shows the exact same pattern. In Futalognkosaurus the first dorsal is indeed longer than the next three, but the fact that the dorsals are partially prepared makes any claims about the proportions of the rear dorsals much harder to verify. The front dorsals were prepared first, as shown in the 2008 paper. Don't take everything in a single paper as irrefutably written in stone, I've seen plenty of bad papers and a few good ones. Not picking on Calvo in particular, it's a much more widespread problem.

So I would expect Futalognkosaurus to have longer posterior dorsals. We could be talking about measurements OTHER than the centrum length, like say the neural arch length, when they mention 28cm in the paper. Most of the column being unprepared, it's a strong possibility that many of the posterior "facts and figures" are pure speculation. Which is fine, until the thing is actually completely unpacked and fully prepared.

As for fractal geometry... nice try but fractal geometry is only directly applicable to plants, and only with some strong accommodation for possible deviations. The Fibonnaci set is the core of most plant fractals but there are plenty of structures on trees and whatnot that do not directly derive from it. Now just try using fractal geometry on animals. Good luck. Both fossils and live animals prove that it isn't feasible. Everything from the neck of Tanystropheus to the odd tail club of Mamenchisaurus violates the "perfect" mathematical harmony of fractals. And in any case, fractal geometry NEVER involves the use of long straight lines. It's all about curves and angles, and your straight-edge Futalognkosaurus isn't exactly showing any of the voluptuous attributes of a Mandelbrodt set.

All the same just the way titanosaurs and all sauropods go together, there is NEVER a perfectly straight line on the neural spines of any of them (unless you try to force bones into weird unnatural positions to support an a priori conclusion). Even when the centra articulate in a straight line, they are never all of the same depth, and the neural arches and neural spines vary in different patterns as well. You NEVER EVER find an animal where every single dorsal, sacral, and caudal neural spine is perfectly aligned in a flat straight-edge for many meters. There's always a dip or a rise SOMEWHERE. In Futalognkosaurus, there seems to be a sacral dip, since the sacrum has very short neural spines. Also the 1st caudal has a very slanted posterior centrum surface, indicative of an upward curve to the base of the tail as seen in many later titanosaurs.

So while the dorsals may be in more or less a straight line, there's no guarantee that the dorsal neural spines were all of equal elevation (especially being so slanted in Futalognkosaurus), and that still says nothing about the angle of the sacral spines or the tail! It's very extreme to assume they ALL had an upper surface that formed a perfectly unflinchingly straight horizontal line.

Remember a skeletal of something like this is bound to have flaws, that's why I keep editing mine instead of saying "this is how it was". So it's easy to do a natural-looking skeletal, and regardless of WHAT the dorsal side view photos show (if Calvo ever publishes them!), to this day there's no case of a sauropod, or any animal, whose entire post-cervical spinal column is a perfectly straight line, like it had a giant unwound coat-hanger shoved up its spine. I could draw mine with a dragging tail and suspend all doubts until the whole tail is found, I could argue that any objection to this is pointless "squabbling" until the rest of the tail is found, but that wouldn't be very good science. Every sauropod has some external curve to the spine that follows the neural spines, even if it's not observable in most of the centra. Don't ask me why this is, it's just there, just like in other land animals. There are a million and one different ways to have a curved or even slightly curved spine, and not a single way to have a perfectly straight 180-degree one.

That's just my thoughts on how to make this image more plausible and realistic even when you don't have ALL the information. If you don't think that's a problem then don't change it. :p
palaeozoologist's avatar
Except you have no good reason not to buy the measurements from the 2008 paper. It's not like this is scaling from photographs. The measurements are listed in the paper. There is no good reason to view these measurements as speculation, and there is every reason to assume that they are legit and are talking about centrum length. Look at the context I gave you in that quote, it specifically says "centrum length". There is no reason to believe that they actually neural arch length since they say explicitly that they are talking about centrum length. The comparisons with the changes in centrum length in the cervical series wouldn't sense otherwise. You are grasping for straws here, man.

Furthermore, you comparison to Malawisaurus is actually not in favor of your argument, since the centrum length in the first dorsal is 20 cm long in the last dorsal centrum length is 15.5 cm. In fact, in Malawisaurus all the centrum lengths are less than than the first centrum except the 4th dorsal which is longer than the first. It is true that the 2nd and 2rd dorsals are particularly short compared to the rest of the dorsals in Malawisaurus, but Malawisaurus was not recovered as a lognkosaur, so is somewhat irrelevant here. Even if what you say were true with regards to Malawisaurus it doesn't matter if the measurements show otherwise in Futalognkosaurus. Ruyangosaurus has a hyposphene-hypantrum system and so is probably not a lognkosaur, which lack this feature and is probably irrelevant to this discussion. Mendozasaurus has no posterior dorsals to compare, so it is irrelevant to this part of the discussion. I'm not sure why you think the anterior dorsals are more prepared than the posterior ones. The photos would seem to indicate otherwise--they all appear to be in roughly the same state of preparation. At any rate, all the centra are visible in the photographs that I have seen which is the important part that is relevant to this discussion which suggests all the lengths of the centra were directly accessible for measurement.

I'm not saying whatever was in the paper is written in stone and can't be wrong. What I *am* saying is that the paper says something which you are contradicting for no good reason. You just 'doubt' that they had that feature. That is not a strong argument, and all your other supporting arguments against it are weak at best or are otherwise irrelevant or wrong. As I said, there is no reason to doubt the listed measurements and comparisons, and there is every reason to believe they are true unless further published research shows otherwise.

You completely mistook my point about fractal geometry. My point about fractal geometry was not to justify the specifics of my restoration (I made no such claim that my illustration followed the principles of fractal geometry!) but to show that "organic" shapes and "geometric" shapes are not mutually incompatible and that your argument was a weak one and not based on scientific principles.

I already agreed with you in my last comment that the neural spines don't necessarily articulate in a straight line when the centra articulate straightly. This does not change the fact that, if you change the articulation of the centra somewhat you can get this to occur. So again, my reconstruction is not out of the realm of possibility. This is mainly because I don't show the caudals! Only the soft-tissue outline. So you can harp all you want on how no animal has their vertebrae articulate in a straight line--it doesn't matter because I don't show them that way! Only a soft tissue outline! So your arguing against something I'm not even showing. A soft tissue outline is just that: a soft tissue outline, and one within the realm of not just possibility but plausibility. In fact, soft tissues can tend to make animals look more geometric than the skeleton itself would indicate. A case could be made that the soft tissues would tend to nullify the differences in neural spine height and make the outline more similar to what I have portrayed.

My restoration may be a bit 'extreme' as you say, but animals do extreme things all the time. Furthermore, my restoration isn't as straight as it appears--although it comes close in some places. But definitely not 180 degrees or 0 degrees. Trust me. I have the original. The anterior dorsals are slightly higher and the dorsal column slightly decreases in height from the anterior dorsals to the posterior dorsals. The distal segments of the tail curve downward by the way, so it isn't perfectly straight.

I'm not saying this is how Futalognkosaurus was in real life. No doubt if (and when) a more complete description appears, I will revise my skeletal and revamp my life reconstruction. Until then, I see nothing compelling in your arguments to change my drawings as of the present. My outline is no more speculative as regards the tail and the dorsal column than any other restoration at present since we don't have the appropriate views. You can make an argument that my restoration is not very parsimonious, which is what it seems is what you are trying to do. However, I am not forcing this reconstruction down anybody's throat. Heck, Futalognkosaurus could have had a clubbed tail for all we know. It's not likely, but not impossible. It's not like I added a completely new skeletal structure on the tail here. I have made the caveats obvious and clear on my skeletal reconstruction which this is based off of as regards the knowns and unknowns regarding Futalognkosaurus. So I think this a bit over-the-top, alarmist attitude.

At least I didn't add an extra dorsal to my skeletal reconstruction. ;)
Paleo-King's avatar
At any rate, all the centra are visible in the photographs that I have seen which is the important part that is relevant to this discussion which suggests all the lengths of the centra were directly accessible for measurement.

Dorsal centra in the photographs? Which bloody paper are you looking at? I have both of Calvo et. al.'s papers and they don't show dorsal centra at all. They show anterior dorsal neural spines and diapopyses, that's IT. There's no ventral or side view of the dorsals, only a fuzzy color dorsal view in the first paper, and an black & white antero-dorsal view in the second. The only centra you get to see next to each other in either paper are the sacral centra (and only because the damn things are fused!), and the angle and quality of that picture of them in the second paper is downright awful. :X

BTW, the so-called hyposphene-hypantrum connection in Ruyangosaurus is very weak and rather poorly defined in my view, so there's no way you can discount a possible lognkosaurian relationship. There are only two known vertebrae for crying out loud. And the prezygapopyses on the anterior dorsal are badly distorted, but very similar to Puertasaurus. The authors say there's a hyposphere/hypantrum comlex, but I don't see it in the photos. The rear of the posterior dorsal definetely doesn't show evidence of a true hyposphene and it's very well-preserved - there's no lower part to the "hyposphene" to lock around a hypantrum. The rear of the anterior dorsal is practically flat and squashed beyond recognition, and there's no trace of a hyposphene there, just flattened postzygapophyses forming a shallow point as in Puertasaurus. In fact the entire neural arch is too flat to interlock with anything, period. There is no projecting hyposphene, and the prezygapophyses are badly distorted and in their normal state wouldn't form a hypantrum. BTW, even if there was a true hyposphene or hypantrum in Ruyangosaurus, that wouldn't disprove a Lognkosaurian identity. Lognkosauria is a newly established clade and still rather poorly understood in terms of diversity. And hyposphene-hypantrum complexes pop up in some very odd places without regard to immediate relatives, so I wouldn't be surprised if at least a few as-yet undiscovered lognkosaur species had them. :XD:

Now if they'd found two consecutive Ruyangosaurus vertebrae that interlock, there might be more of an argument for hypantrum-hyposphene. All the same the centra and diapophyses fiy a lognkosaur description, and the posterior dorsal looks a bit like those of Argyrosaurus, so we are talking about a rather derived lognkosaur too, close to the Argyrosaurs. So this is not only relevant to Lognkosauria, it's also very telling about the anterior dorsals following a consistent pattern of being shorter and wider than the posterior ones. Now if only they would find posterior dorsals for Puertasaurus and Mendozasaurus....

At least I didn't add an extra dorsal to my skeletal reconstruction. ;)

Hahahahaha yeah dude, but I revamped the entire pelvis and the dorsal neural spines on mine to follow the known photos, it's way sexier than your version and it actually looks symmetrical :D Plus I've got more revisions coming up, so it ain't over, not by a long shot.

I'll take out a dorsal when I see proof of its absence - like the COMPLETE dorsal column for instance? Maybe with the pelvis included for comparison? It's not like Duke Energy seized all the bones for themselves! When was Dr. Calvo coming out with that third paper again? 8-)
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