Problems in Erickson et al. 2009

In the course of pursuing research on dinosaur growth rates (Myhrvold, 2013), I attempted to replicate the findings of Erickson et al. for Psittacosaurus lujiatunensis (Erickson et al., 2009a). In their study, they use femoral length measurements and age estimates for 80 specimens of P. lujiatunensis to estimate body mass and age, fit a growth curve, and construct a life table. These results were then used to describe certain aspects of developmental timing and to compare with growth in other dinosaurs as well as extant birds and mammals.