A cloacal opening in a non-avian dinosaur

@article{Vinther2021ACO,
  title={A cloacal opening in a non-avian dinosaur},
  author={Jakob Vinther and Robert Nicholls and Diane A. Kelly},
  journal={Current Biology},
  year={2021},
  volume={31},
  pages={R182-R183}
}
Oldest preserved umbilical scar reveals dinosaurs had ‘belly buttons’
Background In egg-laying amniotes, the developing embryo is tethered to a number of the extraembryonic membranes including the yolk sac and allantois that deliver oxygen and nutrients and remove
Morphology and distribution of scales, dermal ossifications, and other non‐feather integumentary structures in non‐avialan theropod dinosaurs
TLDR
The morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications are reviewed.

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