I might be paraphrasing this wrong, but it was something about the whole spine from the torso to the tail was too large and thus making the animal's linear dimensions too big. I'll ask them about it again because my memory isn't the best.
Ohhhh, that was years ago. When I overhauled it last year to incorporate the new positioning information from Evers et al., 2015 I also updated the scale bar, etc.