Pelvis morphology suggests that early Mesozoic birds were too heavy to contact incubate their eggs

@article{CharlesDeeming2018PelvisMS,
  title={Pelvis morphology suggests that early Mesozoic birds were too heavy to contact incubate their eggs},
  author={D. Charles Deeming and Gerald Mayr},
  journal={Journal of Evolutionary Biology},
  year={2018},
  volume={31}
}
Numerous new fossils have driven an interest in reproduction of early birds, but direct evidence remains elusive. No Mesozoic avian eggs can be unambiguously assigned to a species, which hampers our understanding of the evolution of contact incubation, which is a defining feature of extant birds. Compared to living species, eggs of Mesozoic birds are relatively small, but whether the eggs of Mesozoic birds could actually have borne the weight of a breeding adult has not yet been investigated… 

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