More than One Way of Being a Moa: Differences in Leg Bone Robustness Map Divergent Evolutionary Trajectories in Dinornithidae and Emeidae (Dinornithiformes)

摘要: The extinct moa of New Zealand included three families (Megalapterygidae; Dinornithidae; Emeidae) flightless palaeognath bird, ranging in mass from 200 kg. They are perceived to have evolved extremely robust leg bones, yet current estimates body very wide confidence intervals. Without reliable estimators mass, the extent which dinornithid and emeid hindlimbs were more than modern species remains unclear. Using convex hull volumetric-based method on CT-scanned skeletons, we estimate a female Dinornis robustus (Dinornithidae) at 196 kg (range 155-245 kg) Pachyornis australis (Emeidae) as 50 33-68 kg). Finite element analysis femora tibiotarsi two six showed that P. experienced lowest values for stress under all loading conditions, confirming it be highly robust. In contrast, femur D. similar those birds, whereas tibiotarsus highest level any palaeognath. We consider these Dinornithiformes diverged their biomechanical responses selection robustness mobility, exaggerated hindlimb strength was not only successful evolutionary pathway.