A New Mammaliaform from the Early Jurassic and Evolution of Mammalian Characteristics

@article{Luo2001ANM,
  title={A New Mammaliaform from the Early Jurassic and Evolution of Mammalian Characteristics},
  author={Z. X. Luo and Alfred W. Crompton and Ailin Sun},
  journal={Science},
  year={2001},
  volume={292},
  pages={1535 - 1540}
}
A fossil from the Early Jurassic (Sinemurian, ∼195 million years ago) represents a new lineage of mammaliaforms, the extinct groups more closely related to the living mammals than to nonmammaliaform cynodonts. It has an enlarged cranial cavity, but no postdentary trough on the mandible, indicating separation of the middle ear bones from the mandible. This extends the earliest record of these crucial mammalian features by some 45 million years and suggests that separation of the middle ear bones… Expand
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