Origin of the Lateral Wall of the Mammalian Skull: Fossils, Monotremes and Therians Revisited

  title={Origin of the Lateral Wall of the Mammalian Skull: Fossils, Monotremes and Therians Revisited},
  author={Alfred W. Crompton and Catherine Musinsky and Guillermo W. Rougier and Bhart‐Anjan S. Bhullar and Juri A. Miyamae},
  journal={Journal of Mammalian Evolution},
To interpret the fundamental differences in the structure and origin of the braincase sidewalls of monotremes, multituberculates, and therians, we examined MicroCT scans of a mammaliaform, Morganucodon; two non-mammalian cynodonts, Massetognathus and Probainognathus; a stem therian, Vincelestes; a juvenile and adult monotreme, Ornithorhynchus; and two marsupials, Monodelphis and Didelphis. The skull of Morganucodon resembles the pattern predicted for an early mammal: the descending flanges of… 
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