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tttGDIintermediate by Franoys

TyrannotitanGDI by Franoys

Here you have the previous calculations made with the method used; graphical double integration, a type of vollumetric estimation.

A mathematical analysis on Giganotosaurus mass.First of all, the results:


Conclussions , methodology, and anatomical references: 
For those who don't know which method was used, I recommend reading the previous journal entry, about a mathematical anaylsis on Spinosaurus mass , another legendary carnivorous dinosaur; and this excelent post by SVPOW. https://svpow.com/2011/01/20/tutorial-11-graphic-double-integration-or-weighing-dinosaurs-on-the-cheap/
Overall the method intends to construct a simplified 3D model of the animal by building eliptical cross sections and adding them up, given two views of each of it's body sections. The analysis is performed by a matlab mathematical script with pixel accuracy.
The skeletal used is my own bet on the animal. Sadly, and despite more than 22 years having passed since the animal was first (and very briefly) described, most of it's material is not described in detail, specially the axia


A mathematical analysis on Spinosaurus mass.Description of the method:
Graphical double integration performed by Matblab program.
We calculated the mass of the North african theropod dinosaur Spinosaurus aegyptiacus, using a graphical double integration method. We believe GDI is in itself, and without a doubt, one of the best methods to calculatte the mass of extint organisms, and the best that can be used using a multi views silhouette from the animal. The method averages a big amount of eliptical sections to aproximate the volume of a complex 3D object. The more eliptical sections, the more accurate the result will be, when a number of slices made is surpassed the result will be almost real life-like.
This matlab program utilizes digital image processing technology to analize two silhouettes from different views. It counts the number of non white pixels in every pixel-wide column from the image, and produces one slice per pixel. In response, the program is extremely sensitive to irregularities in the silho


The method consists in constructing a simplified 3D model of the animal mathematically, by building eliptical cross sections and adding them up, given two views of each of it's body sections. The analysis is performed by a matlab mathematical script with pixel accuracy. More information about the method itselft here:

svpow.com/2011/01/20/tutorial-…

Some discussing about Tyrannotitan size and overall proportions:

The skeletal used was made by me from scratch, using mainly the information (figures, measurements, and descriptions) in Novas (2005) and Canale , Novas (2014); using Sereno 1996, Coria 1995, and Currie and Carpenter 2000 to fill in the gaps, because Tyrannotitan is not complete, even if it is one of the most complete Carcharodontosaurids that we have by far and long. And it also is one to have a detailed description with a well documented supplementary materials, unlike others like Giganotosaurus which never seems to get a detailed osteological study, even 22 years after the brief and undetailed (and now vastly outdated in every possible sense) description of Mucpv Ch1.

The top view was again modified from Acrocanthosaurus. The width of the skull, and consequently that of the anterior portion of the neck, is intermediate between Carcharodontosaurus and Giganotosaurus, the two most closely related animals to Tyrannotitan, which also preserve a decent portion of their respective skulls. It wouldn't surprise me that the head was wider than what I gave it credit for, since after all, Tyrannotitan is strongly bounded to the tribe Giganotosaurini, even more so than to the subfamily Carcharodontosaurinae, which includes Carcharodontosaurus.

I gave Tyrannotitan an equivalent ribcage width as to Acrocanthosaurus based on comparisons of the vertebrae of the former with that of later. The hips however are wider, following the suggestion of a 40 cm wide hip for Tyrannotitan holotype, as per suggested by Canale 2014. If the paratype was about 7% bigger in average as Novas 2005 suggests, the hip of the paratype would be 42.8 cm wide, which was wider than the Acrocanthosaurus hip scaled to match the length of that of Tyrannotitan.

There are more indications of Tyrannotitan being bulky for it's length compared to other Carcharodontosaurids and Allosauroids, like it's femur circumference; which at 541 mm (Canale 2014 supp materials) would be greater than that of Giganotosaurus holotype ( 520 mm, Campione et al 2014). 

Tyrannotitan of course also has other peculiarities that are woth discussing and that had an impact on it's body mass; for example it's dorsal vertebrae being anteroposteriorly short. None of the vertebrae of the paratype has a centrum over 14 cm long (Canale 2014, supp materials) except one, which barely pushes 15.5 m, furtheremore the 1st and the 14th dorsal are very reduced compared to the other vertebrae wich yields a torso length of about 85% that of Giganotosaurus, which explains the (perhaps) lower than expected body length estimation.

The most cited length of 12.2 m is cited from the theropod database, and the estimation was made way before the detailed osteological study came out, and was probably based on femur scaling using Giganotosaurus as a base. However after the publication of Canale 2014 Tyrannotitan having an equivalent body length to Giganotosaurus doesn't hold up.

Tyrannotitan also shows very tall neural spines, much taller than those of Giganotosaurus. Such feature helps expanding the torso depth and incrementing it's mass, furtheremore the pubis is 11 cm longer than the measurement for Giganotosaurus in the theropod database and 10 cm longer than the extrapolated pubis length of the biggest Carcharodontosaurus specimen (SGM din 1). Even if we were to be skeptical about the extrapolation, Carcharodontosaurus (IPHG 1922) reconstructed pubis was only 1 meter long compared to a 1.26 m long femur, or 79% the length of the femur, while in Tyrannotitan the reconstructed pubis is 86% the femur length, suggesting again that Tyrannotitan had a deep torso, despite it being relatively shorter than in Giganotosaurus.

The skull elements suggest a skull of very large size, specially length; the jugal matches almost exactly in size and shape to the same element in Carcharodontosaurus (SGM din 1) and the dentary of the Tyrannotitan paratype is comparable in size to that of both Giganotosaurus specimens, so Tyrannotitan is certainly a big headed animal, as are all of the members of Carcharodontosaurinae. The preserved quadratojugal in Tyrannotitan and how it articulates and compares in size with the jugal offers valuable information on to how to restore the rear portions of Carcharodontosaurines' skulls.

Link to the Tyrannotitan restorations:

Tyrannotitan chubutensis Skeletal Diagrams. by Franoys

Carcharodontosaurus will be the next, and will come with a couple surprises. Stay tuned!

References:

Juan Ignacio Canale, Fernando Emilio Novas & Diego Pol , Historical Biology (2014): Osteology and phylogenetic relationships of Tyrannotitan chubutensis Novas, de Valais, Vickers-Rich and Rich, 2005 (Theropoda: Carcharodontosauridae) from the Lower Cretaceous of Patagonia, Argentina, Historical Biology: An International Journal of Paleobiology.

Fernando E Novas, Silvina de Valais, Pat Vickers-Rich, Tom Rich (2005): A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids

Paul C. Sereno, Didier B. Dutheil, M. Larochene, Hans C. E. Larsson, Gabrielle H. Lyon, Paul M. Magwene, Christian A. Sidor, David J. Varricchio, Jeffrey A. Wilson (1996): Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation. Science, New Series, Vol. 272, No. 5264 (May 17, 1996), pp. 986-991

Rodolfo A.Coria, Leonardo Salgado (1995) A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature, Vol 377 (September 21 1995)

Currie P. J. & Carpenter K. 2000. — A new specimen of Acrocanthosaurus atokensis (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA. Geodiversitas 22 (2) : 207-246.

Stromer 1931 II. Vertebrate remains from the Baharîje Beds (lowermost Cenomanian). 10. A skeletal remain of Carcharodontosaurus nov. gen. 
:iconthedinorocker:
thedinorocker Featured By Owner Feb 4, 2017
A mass around 6.5 tons for Big Carcharodontosaurids is strongly suggested
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