Post by dinosauria101 on Feb 4, 2020 22:01:40 GMT 5
So as we all know, the holotype of Dreadnoughtus, despite having its mass overestimated by over 10 tonnes using limb bone regressions, was still a juvenile at the time of death. How large an adult would be is unknown, but might it be approaching the very biggest dinosaurs in size as an adult due to its overbuilt limbs which could have been there pre-emptively to carry large weights? Greg Paul makes a good point about this on Page 19 of his 2019 paper on giant sauropods, here (link). To quote him:
The holotype of Dreadnoughtus was likely around 48.45 tonnes (Matt Wedel did a GDI of the paper's skeletal and got 57 cubic meters, which gets 48.45 tonnes with the proper density of 0.85), so it was a very large animal already and could well have gotten a lot bigger. How plausible might it be for adults to be among the biggest sauropods ever, based on this? Discuss.
The same-scale comparison of titanosaurian humeri and femora (Fig. 3) reaffirms that, even by titanosaur standards, those of Dreadnoughtus are atypically overmassive relative to those of its larger-bodied relatives, perhaps because (based on osteohistological evidence presented by Lacovara et al. 2014) the holotype was a juvenile or subadult that would ultimately have matured into a much more massive adult. Sauropod, including titanosaur, limb bone growth appears to have been largely isometric (Bonnan 2007; Curry Rogers et al. 2016), and if adult Dreadnoughtus regularly approached or exceeded 100 tonnes, then beginning their lives with exceptionally robust limb bones may have been a means for such heavybodied herbivores to be structurally prepared for the extreme masses they may eventually have attained.
