Hi Ovleg; sorry for answering late; I hope the answer won't be too longFirst regarding the femora alone; I had a conversation regarding this with him on his blog, although I was using a Tablet with a horrible autowrite so some parts are very hard to understand.As I told you before, Tyrannotitan's femur circumference is 500 or 514 mm for MPEF PV 1156 and 541 mm for MPEF PV 1157 respectively; the mass of MPEF PV 1156 was calculated in Campione & Evans 2014 resulting in it being smaller tan that of Tyrannosaurus (femur circumference up to 580 mm for the more robust specimens) and Giganotosaurus (femur circumference of 521-525 mm). The conclussion in that reviewed paper is that Tyrannosaurus is most massive based on femoral proportions. Dr Cau wasn't aware of it when I talked with him; that's why he went to compare solely the mediolateral diameters cited in Canale 2014 and Brochu 2003. Here is the paper besjournals.onlinelibrary.wile… I have plotted the circumference values for both specimens in the equation provided in Campione and Evans 2014, and it has yielded smaller masses for Tyrannotitan (maximum mass 6994 kg) than for Tyrannosaurus (maximum mas 8472 kg) and Deinocheirus (maximum mass 7692 kg; it has a femur circumference 560 mm, the second most robust in theropoda, more robust than the femur of Tyrannotitan)Here are the results, it includes every theropod in existance that has femora preserved:Here is a versión with the larger theropods only cdn.discordapp.com/attachments… The thing is that going by the SM in Canale 2014 the Tyrannotitan specimens have an unusually large medio-lateral diameter measurement (295 mm when that measurement doesn't exceed 160 in any other theropod including Giganotosaurus and other Carcharodontosaurids with larger or as large skull elements and vertebrae as Tyrannotitan). The large diameter makes it so the eccentricity defined by the elipse of the cross section is about 1.8 instead of 1.15 like in Giganotosaurus, which is closely related and has a femur circumference in the range of Tyrannotitan and perhaps a longer one (more on length later).If we trust the diameters as listed in the Canale 2015 SM, we would get a circumference of over 746 mm, much larger tan the real one ( by over 200 mm). If we plotted 746 mm in the circumference equations (they are always done with circumferences, not diameters, but perimeter/circumference is directly dependant on diameter size anyway) we get a mass of 16945 kg for Tyrannotitan which is a physical absurdity looking at the size of the reconstructed volumetric model, even considering the lateral view of the skeletal alone . If we do a photographic analysis of the figured femur in Canale et al 2014, we see that the femur eccentricity at the middle of the shaft is 1.15, not 1.8. Therefore the diameters listed in the SM are not correct, as we deduct that the diameter listed is absurd following 4 different criteria.He said he would consult the authors to clean this up but didn't, therefore I will, i need the measurements either way for a thesis in preparation.Regarding femoral length, Carcharodontosaurids have proximally inclined femoral heads (as acknowledged in the supplementary materials of Benson et al 2014), so the length measured in the medial side is greater than measured in the lateral side. In Tyrannosaurus, theese measurements are equivalent because the femoral head is at the level of the greater and lesser trochanters. Measured along the lateral side, the femora of Giganotosaurus, Tyrannotitan, and Tyrannosaurus are the same length.This is all about the femur, but regarding allometry estimations as a whole:Dr Cau refers to how allometry estimates are more objective than volumetric ones but this is sadly not correct. A rigorous volumetric model is much more exact and more preferable as discussed here: svpow.com/2011/01/20/tutorial-… and in this paper by Gregory S.Paul: citeseerx.ist.psu.edu/viewdoc/… Approaches based on the robusticy of the femur+humeri have failed misserably before, as many experts in biomechanics acknowledge: rsbl.royalsocietypublishing.or… and here: rsbl.royalsocietypublishing.or… Reducing things to comparing sizes of the femur only is a dramatic over simplification of the matter, as is reducing bio mechanical calculations to supossed personal biases. Remember also that not every taxon preserves femora, it is a large bone and hard to entomb in gigantic animals. Look at this chart, most of ths specimens here don't have femora preserved, but the individual bones still suggest animals of very big size.Limb bone strength is not constant in land animals, but varies greatly in forms with different limb designs and locomotory abilities. Tyrannosaurus limb design varies a lot from that of Carcharodontosaurids because it has greater tibial and metatarsal length compared to the femur length, a condition inherited from the cursorial taxa it evolved from (consider tibiae and metatarsus also contribute to weight bearing).Also diameter measurements can vary extremely within individuals of the same taxón that have the same dimensions in virtually all of the bones, therefore it is variable as long as it is in a range in which it can sustain the animal. In other words, the same femur can sustain an animal of which it's mass varies a 100%. One real life example of this is that the same femora can sustain the same 75 kg man if he loses or gains 25 kg.I have produced my volumetric model reconstructing all the sections of the animal and with as much precisión as was posible, the vertebral measurements of Tyrannotitan don't suggest a theropod of super massive size almost 17 metric tonnes; it's longest dorsal vertebrae is 15.8 cm while the longest vertebra of Tyrannosaurus is almost 20, and it's torso length width and depth, the most massive parts of the body, are much smaller than in Tyrannosaurus and smaller than in Giganotosaurus.Note that I have always admired Dr.Andrea Cau greatly, but I do not think he is right in this matter.