Tyrannosaurus rex

[tigerluver]

Regarding the new comparative estimates published by Persons et al. (2019), a major flaw is that they only gave regard to femoral circumference. This would cause an intrinsic bias toward animals who had greater femoral circumference but short bone length in terms of mass estimation. In other words, the estimate completely disregards any key part of the animal's frame. As an analogy, imagine Smilodon. From Christiansen and Harris (2005), we can use CN11 as an example. The regression-based estimates for this specimen were 243.6 kg based on length and 516 kg based on least circumference. Both estimates are probably very much off and the true weight is somewhere between those two. In Persons et al. (2019), this analogy shows use of only femoral circumference would result in overexaggeration of Scotty's mass at least relative to thinner but longer boned therapods like Giganotosaurus. The scale factor used by Persons et al. (2019) is also quite nearly isometric at 2.754, making it unlikely the factor deducted enough for short but stout boned animals. Single measurement estimates can be accurate, but only in the case of intraspecific comparison, like comparing a lion to a lion. Reply