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Patagotitan mayorum skeletal reconstructions by SpinoInWonderland Patagotitan mayorum skeletal reconstructions by SpinoInWonderland
Patagotitan mayorum ("The Mayo family's Patagonian titan"), the Chubut Monster, is a species of gigantic titanosaurian sauropod that lived on what is now Patagonia, Chubut Province of Argentina, South America during the Albian stage of the Middle Cretaceous. It was first excavated and exposed to the media in 2014, and described in 2017.

It was initially speculated to be ~37 metres long, with a femur stated to be in various sizes ranging from ~2.4 metres to ~3 metres. The measurements in the description then showed that the gigantic ~37-metre figure as implausible for any of the known specimens given regular titanosaur proportions.

It is commonly famed for being larger than Argentinosaurus and Puertasaurus, however, this seems to be an exaggeration for the known specimens. However, it's transverse width is still greater than in Argentinosaurus, suggesting a proportionally wide ribcage.

I initially had a loose guess that this creature would turn out ~35 metres long or more before this skeletal reconstruction, but after working on it, I figured that this may be a bit excessive for the known specimens. However, given that the holotype has an unfused scapulacoracoid and that bone histology analysis found the known individuals to be subadults, adults would have grown larger than in these reconstructions. The schematic skeletal in the description was subpar to say the least, but it sufficed in very rough shapes for many of the bones.

The Patagotitan specimens were complete enough as a whole to base most of the proportions on other conspecific specimens rather than related taxa. The holotype MPEF-PV 3400 and paratype MPEF-PV 3399 were cross-scaled via the 8th dorsal, which overlaps between them in an uncrushed and unbroken state. MPEF-PV 3397 and the rest of the paratypes were composited into one and scaled down from the holotype reconstruction. The sacrum, ilium, lower hindlimb proportions, and humerus:femur proportions were based on Futalognkosaurus. Since illustrations of the caudals are quite scarce, and the description's schematic doesn't have them in a good-enough resolution to use, many of the caudals were roughly illustrated using Dreadnoughtus. The cervical count was reduced from the 15 used in the description to 14, based on Futalognkosaurus. And since the anterior dorsals were quite crushed, cross-scaled Futalognkosaurus dorsals were used to estimate their uncrushed lengths. The skull is a speculative transitional morph based on a cross between Tapuiasaurus, Malawisaurus, and Narambuenatitan.

The left and right femora in MPEF-PV 3399 and humeri of the MPEF-PV 3397 + other paratypes composite were swapped in the lateral view skeletals in order to show off the preserved and illustrated elements. Bones which are well-illustrated in the description or external photographs are in white, while bones which are unillustrated or poorly-illustrated are in light grey. Illustrated bones with unspecified specimens in the description's figures (such as the first caudal) are marked as illustrated in all specimens which preserve said bone.
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Measurements for MPEF-PV 3400:

Hip height: ~4.76 metres

Shoulder height: ~5.48 metres

Total height: ~13.21 metres

Standing length: ~26.5 metres

Axial length: ~30.82 metres
__

Measurements for MPEF-PV 3397 + other paratypes, scaled to MPEF-PV 3397:

Hip height: ~4.29 metres

Shoulder height: ~4.94 metres

Total height: ~11.9 metres

Standing length: ~23.88 metres

Axial length: ~27.77 metres
__

Measurements for MPEF-PV 3399:

Hip height: ~4.75 metres

Shoulder height: ~5.25 metres

Total height: ~12.33 metres

Standing length: ~26.83 metres

Axial length: ~30.79 metres
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References/sources:

Carballido et al., 2017, "A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs"
Calvo et al., 2007, "Anatomy of Futalognkosaurus dukei Calvo, Porfiri, Gonzales Riga & Kellner, 2007 (Dinosauria, Titanosauridae) from the Neuquen Group(Late Cretaceous), Patagonia, Argentina"
Gomani, 2005, "Sauropod dinosaurs from the Early Cretaceous of Malawi, Africa"
Filippi et al., 2010, "A new titanosaur sauropod dinosaur from the Upper Cretaceous of North Patagonia, Argentina"
Wilson et al., 2016, "The skull of the titanosaur Tapuiasaurus macedoi (Dinosauria: Sauropoda), a basal titanosaur from the Lower Cretaceous of Brazil"
Calvo, 2014, "New fossil remains of Futalognkosaurus dukei (Sauropoda: Titanosauria) from the Late Cretaceous of Neuquen, Argentina"
Lacovara et al., 2014, "A gigantic, exceptionally complete titanosaurian sauropod dinosaur from southern Patagonia, Argentina"
Gonzalez-Riga et al., 2016, "A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot"
Greg Paul, 2016, "The Princeton Field Guide to Dinosaurs"
Scott Hartman's Futalognkosaurus
Patagotitan arm photo
Patagotitan femur photo 1
Patagotitan femur photo 2
Patagotitan mount photo 1
Patagotitan mount photo 2
Patagotitan mount photo 3
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UPDATE(4/29/2018): Added detail, replaced the skull, and scalebar updated to my new conventions. See the previous version here for comparison.
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:iconpaleonerd01:
Paleonerd01 Featured By Owner Aug 28, 2018  Hobbyist Traditional Artist
Do you know what the diameter of the caudal vertebrae for MPEF-PV 3399 is? 
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Aug 28, 2018
Based on the measurements from the Carballido et al. (2017) supplementary data, the first caudal centrum is about 36 centimetres wide and 46 centimetres deep at the posterior end, the middle caudal centra (19th-30th) are around ~20-33 centimetres across, and the distal caudal centra (36th-44th) are about ~13-16 centimetres across.
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:iconpaleonerd01:
Paleonerd01 Featured By Owner Aug 28, 2018  Hobbyist Traditional Artist
Thank you very much i appreciate it greatly, one more question if you don't mind, do you know what the diamante of the caudal vertebrae of 3400 is? 
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Aug 29, 2018
Based again on the Carballido et al. (2017) supplementary, the first caudal is about 33 cm long and 40 cm deep, the 3rd and 4th caudals are about 44 cm deep with no listed width, 5th is about 29 cm wide and 36 cm deep, 7th is about 37 cm wide and 40 cm deep, and the 8th is about 32 cm wide and 34 cm deep.
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:iconmajestic-colossus:
Majestic-Colossus Featured By Owner Jun 25, 2018
I wonder how some people got only ~5m at the scapula for the biggest specimen, given that we have a pretty good idea of how long its arms were and such.
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Jun 26, 2018
It's because they simply composted the MPEF-PV 3397 humerus into MPEF-PV 3400/MPEF-PV 3399 despite MPEF-PV 3399 being an isolated element that lacks any overlap with MPEF-PV 3400/MPEF-PV 3399, rather than actually trying to cross-scale to figure out an estimated femur length for the specimens.
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:iconmajestic-colossus:
Majestic-Colossus Featured By Owner Jun 26, 2018
I see.
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:iconcandelediva:
candelediva Featured By Owner Oct 16, 2017
It's beautiful
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:iconkirkseven:
kirkseven Featured By Owner Oct 8, 2017
looks good.
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:iconforbiddenparadise64:
ForbiddenParadise64 Featured By Owner Oct 2, 2017
Nice to see a robust titanosaur model that isn't just based off the museum mount with its absurdly narrow torso (even *Diplodocus* didn't have a torso narrower than the pelvis) and Diplodocus like head. The latter is where the 44 and 55 tonne estimates come from. 
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Oct 2, 2017
The head in the mount isn't anything like a Diplodocus head, it's a cross between a duckbill and a pseudo-nemegtosaur head ;) (Wink)

s1.ibtimes.com/sites/www.ibtim…
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:icondinosaurlover83:
Dinosaurlover83 Featured By Owner Oct 1, 2017  Student Artist
nice
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:iconjonagold2000:
JonaGold2000 Featured By Owner Oct 1, 2017  Hobbyist Traditional Artist
Where did you get the ribs, femur sideview, forearms, ischium, pubis, illium, manus, and the shapes of the anterior dorsals? The forearms, ribs, illium, ischium, pubis and femur are all only available in pictures of the mount and they dont resemble said mount very much. The vertebrae dont look anything like the ones figured, I know theyre poorly illustrated and sometimes crushed but that is no excuse for this level of discrepancy.
And thats not even mentioning your rejection of the phylogeny out of no other reason than you not liking the conclusion.
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:iconspinoinwonderland:
For the ribs, forearms, pubis, ischium, and unillustrated dorsals, it's in the description here itself:

"The schematic skeletal in the description was subpar to say the least, but it sufficed in very rough shapes for many of the bones."

Ilium is based on Futalognkosaurus. Did you just hastily skim through the text here?

The lateral view of the femur is generic. Manus was copy-pasted from the ones I already used in my longkosaur skeletals.


"The vertebrae dont look anything like the ones figured, I know theyre poorly illustrated and sometimes crushed but that is no excuse for this level of discrepancy."

What do you mean? If you're talking about the ones illustrated in detail here, I merely corrected for crushing, breakage, and distortion. Care to elaborate?


"And thats not even mentioning your rejection of the phylogeny out of no other reason than you not liking the conclusion."


It's not a matter of just "not liking the conclusion", it's that it's generally inconsistent with the few consistent things Titanosauria had:
  • Almost all analyses had aeolosaurids at least close to Saltasauria if not part of it AFAIK. They're known from extensive material as well, not much gaps. How did that get moved from it's consistent and repeated placement suddenly into longkosauria just because of one taxon?
  • How did Argentinosaurus get thrown into derived longkosauria all of a sudden? Argentinosaurus consistently scored as a basal titanosaur in most analyses, and it's not like the Argentinosaurus material we have somehow increased without anyone ever reporting on it.

In any case, it won't change anything in this reconstruction aside from the head.

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:iconjonagold2000:
JonaGold2000 Featured By Owner Oct 3, 2017  Hobbyist Traditional Artist
"The schematic skeletal in the description was subpar to say the least, but it sufficed in very rough shapes for many of the bones."
You say this but it's not seen in the results, and trust me I read the description.

"What do you mean? If you're talking about the ones illustrated in detail here, I merely corrected for crushing, breakage, and distortion. Care to elaborate?"
The anterior dorsals particularly don't resemble the figured ones at all.

"It's not a matter of just "not liking the conclusion", it's that it's generally inconsistent with the few consistent things Titanosauria had:
  • Almost all analyses had aeolosaurids at least close to Saltasauria if not part of it AFAIK. They're known from extensive material as well, not much gaps. How did that get moved from it's consistent and repeated placement suddenly into longkosauria just because of one taxon?
  • How did Argentinosaurus get thrown into derived longkosauria all of a sudden? Argentinosaurus consistently scored as a basal titanosaur in most analyses, and it's not like the Argentinosaurus material we have somehow increased without anyone ever reporting on it.

In any case, it won't change anything in this reconstruction aside from the head."
You're rejecting the phylogeny purely based on the results, I've heard no critique from you about the actual methodology, just that the results are not what expect and therefore wrong. The inclusion of a new complete taxa will do that to an unstable clade. Even if there are some relatively complete taxa already.

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:iconspinoinwonderland:
"You say this but it's not seen in the results, and trust me I read the description."

It's the combined effect of shape refinement (so it doesn't look like a mess, e.g. giving the neural spine shapes a smoother series progression, etc.) and converting a dirty low-res pixellated shape into a clean high-resolution outline. Rough and basic, not exact.


"The anterior dorsals particularly don't resemble the figured ones at all."

Seeing from the figures that the 2nd dorsal basically looks as if it were squashed by a steamroller anteroposterorly, and every dorsal from the 1st to the 3rd were compressed, I used Futalognkosaurus dorsals cross-scaled via the 5th dorsal (the anteriormost uncrushed dorsal) to roughly estimate uncrushed lengths for them. I then stretched the D2 lateral view figure to that length and corrected some remaining distortion, such as the squashed anterior ball, decompressing it using Puertasaurus and Pitekunsaurus as rough guides. As for the front view, I just looked for the side that has longer transverse processes (since that's the side less likely to be crushed, crushing usually doesn't extend transverse processes but can easily compress them) and mirrored it, then corrected some remaining asymmetrical distortion. As for the 3rd dorsal, I restored it's neural spine based on the 2nd dorsal rather than taking it from Argentinosaurus like the paper did (which caused a sudden and abrupt shape difference between the D2 and D3 neural spines), as you would reasonably expect a neural spine's shape to not differ too drastically from the ones just adjacent to it in the series.


"You're rejecting the phylogeny purely based on the results, I've heard no critique from you about the actual methodology, just that the results are not what expect and therefore wrong. The inclusion of a new complete taxa will do that to an unstable clade. Even if there are some relatively complete taxa already."

It's just another titanosaur analysis, just another one. And one I'm not very convinced of since it, as I said, generally inconsistent with the few consistent things Titanosauria had over more than 2 decades of phylogenetic analyses. Argentinosaurus being a basal form was repeatedly found in analyses consistently. Aeolosaurines being close to Saltasauria was repeated numerous times and consistently at that. They stood the test of time well. I don't think one new analysis short of the ones on the scale Tschopp and co. do would topple all that alone. Futalognkosaurus is more complete than Patagotitan, and it failed to bring stability to the clade. The numerous titanosaurs more complete than Patagotitan and even Futalognkosaurus (mostly saltasaurs AFAIK) didn't do that either. Now, I'm not saying that everyone who uses it is wrong, if you're convinced by it, it's fine, but I don't recommend taking every single new titanosaur analysis at face value.

As for using Tapuiasaurus skulls for longkosaurians, that was from a time when I was less aware of Titanosauria's instabilities and due to my awareness of it by now, I just don't feel safe swapping that every time Titanosauria transforms it's tree again. It's just something that happened to have stayed rather than something I have a strong conviction towards.
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:iconjonagold2000:
JonaGold2000 Featured By Owner Oct 16, 2017  Hobbyist Traditional Artist
''It's the combined effect of shape refinement (so it doesn't look like a mess, e.g. giving the neural spine shapes a smoother series progression, etc.) and converting a dirty low-res pixellated shape into a clean high-resolution outline. Rough and basic, not exact.''

The discrepancy is still rather large however, I'll take the pubis and illium as examples. The schematic shows the Illium curving around to have the illiac hook practically touching the bone again, which is not how the bone is drawn in your schematic. The one you drew is basically a Futalongkosaurus illium. The pubis has the opposite, it is much broader than paper shows it to be, again being more like that of Futalongkosaurus.

''Seeing from the figures that the 2nd dorsal basically looks as if it were squashed by a steamroller anteroposterorly, and every dorsal from the 1st to the 3rd were compressed, I used Futalognkosaurus dorsals cross-scaled via the 5th dorsal (the anteriormost uncrushed dorsal) to roughly estimate uncrushed lengths for them. I then stretched the D2 lateral view figure to that length and corrected some remaining distortion, such as the squashed anterior ball, decompressing it using Puertasaurus and Pitekunsaurus as rough guides. As for the front view, I just looked for the side that has longer transverse processes (since that's the side less likely to be crushed, crushing usually doesn't extend transverse processes but can easily compress them) and mirrored it, then corrected some remaining asymmetrical distortion. As for the 3rd dorsal, I restored it's neural spine based on the 2nd dorsal rather than taking it from Argentinosaurus like the paper did (which caused a sudden and abrupt shape difference between the D2 and D3 neural spines), as you would reasonably expect a neural spine's shape to not differ too drastically from the ones just adjacent to it in the series.''

Well what about their actual shape though? Just like in Argentinosaurus Patagotitan's neural spine curves posteriorly, this is not reflected within your skeletal however. This amount of distortion applied to the vertebrae renders it basically useless for a comparison to Argentinosaurus since most of the similarities between the two have been reconstructed away.

''It's just another titanosaur analysis, just another one. And one I'm not very convinced of since it, as I said, generally inconsistent with the few consistent things Titanosauria had over more than 2 decades of phylogenetic analyses. Argentinosaurus being a basal form was repeatedly found in analyses consistently. Aeolosaurines being close to Saltasauria was repeated numerous times and consistently at that. They stood the test of time well. I don't think one new analysis short of the ones on the scale Tschopp and co. do would topple all that alone. Futalognkosaurus is more complete than Patagotitan, and it failed to bring stability to the clade. The numerous titanosaurs more complete than Patagotitan and even Futalognkosaurus (mostly saltasaurs AFAIK) didn't do that either. Now, I'm not saying that everyone who uses it is wrong, if you're convinced by it, it's fine, but I don't recommend taking every single new titanosaur analysis at face value.

You could that about any other titanosaur phylogeny, we know it's a clade with very unstable taxonomy. It's also the only tree so far which includes Patagotitan, which should defenitely be included for obvious reasons. The inclusion of a new taxon like Patagotitan can mess with a generally accepted tree like that. The length of time a tree has existed for is no argument for it being better, look at the polyphyletic dinosauria hypothesis. You could say that it's not a good analysis, but saying others are more accurate is impossible to tell atm with no other trees including Patagotitan. Not to mention location in the actual tree is equally important. Now that you mention Futalongkosaurus it's worth mentioning that its actually coded better here than in previous analyses, the coding being based on personal observation rather than copying from others plus the addition of the appendicular skeleton which was missing before. So that makes not one but two complete genera to improve this tree. This isn't even the first time the two ended up close together, Tykoshi also got the two relatively close. And not to mention that the phylogeny would also change base for the vertebra.

As for the Aeolosaurs: cdn.discordapp.com/attachments…

As for using Tapuiasaurus skulls for longkosaurians, that was from a time when I was less aware of Titanosauria's instabilities and due to my awareness of it by now, I just don't feel safe swapping that every time Titanosauria transforms it's tree again. It's just something that happened to have stayed rather than something I have a strong conviction towards.''
Hmm ok I guess.
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:iconspinoinwonderland:
SpinoInWonderland Featured By Owner Oct 16, 2017
"The discrepancy is still rather large however, I'll take the pubis and illium as examples. The schematic shows the Illium curving around to have the illiac hook practically touching the bone again, which is not how the bone is drawn in your schematic. The one you drew is basically a Futalongkosaurus illium. The pubis has the opposite, it is much broader than paper shows it to be, again being more like that of Futalongkosaurus."

Ilium is inferred based on Futalognkosaurus, Patagotitan doesn't preserve it at all. I already stated this earlier in this discussion, as well as in the description. The pubis is like that because I adjusted it to fit the paper's listed distal width figure, and the schematic does show a broader right pubis if you look closely.


"Well what about their actual shape though? Just like in Argentinosaurus Patagotitan's neural spine curves posteriorly, this is not reflected within your skeletal however. This amount of distortion applied to the vertebrae renders it basically useless for a comparison to Argentinosaurus since most of the similarities between the two have been reconstructed away."

Neither the figured dorsals nor the images of the mount show Patagotitan's neural spines having an Argentinosaurus-like curve. They're pretty straight from the 1st to the last dorsal.


"You could that about any other titanosaur phylogeny, we know it's a clade with very unstable taxonomy. It's also the only tree so far which includes Patagotitan, which should defenitely be included for obvious reasons. The inclusion of a new taxon like Patagotitan can mess with a generally accepted tree like that. The length of time a tree has existed for is no argument for it being better, look at the polyphyletic dinosauria hypothesis. You could say that it's not a good analysis, but saying others are more accurate is impossible to tell atm with no other trees including Patagotitan. Not to mention location in the actual tree is equally important. Now that you mention Futalongkosaurus it's worth mentioning that its actually coded better here than in previous analyses, the coding being based on personal observation rather than copying from others plus the addition of the appendicular skeleton which was missing before. So that makes not one but two complete genera to improve this tree. This isn't even the first time the two ended up close together, Tykoshi also got the two relatively close. And not to mention that the phylogeny would also change base for the vertebra."

I do have that thought about some other titanosaur phylogenies, I'm not convinced of Alamosaurus being a longkosaur or Argentinosaurus being an antarctosaurid either. I'll reserve further judgements until I can see the phylogenetic assessments after this one. The recently-described Choconsaurus allegedly has a phylogenetic analysis, but I cannot access it. As for Tykoski's analysis, Argentinosaurus ends up between Epachthosaurus and Longkosauria there rather than it being within Longkosauria itself.
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:iconmajestic-colossus:
Majestic-Colossus Featured By Owner Oct 1, 2017
Very nice! It ended up roughly as long as other estimates I've seen on DA, but more robust.
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:iconpaleosir:
paleosir Featured By Owner Oct 1, 2017  Hobbyist Traditional Artist
Very nicely done skeletal.
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:iconrizkiusmaulanae:
RizkiusMaulanae Featured By Owner Oct 1, 2017  Student Traditional Artist
Toast
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:iconevodolka:
Evodolka Featured By Owner Oct 1, 2017  Hobbyist Traditional Artist
ok then collectively we have SOMETHING that is better than nothing :D
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