Transformation and diversification in early mammal evolution

@article{Luo2007TransformationAD,
  title={Transformation and diversification in early mammal evolution},
  author={Zhe‐Xi Luo},
  journal={Nature},
  year={2007},
  volume={450},
  pages={1011-1019},
  url={https://api.semanticscholar.org/CorpusID:4317817}
}
Newly discovered fossils show that evolution of such key characters as the middle ear and the tribosphenic teeth is far more labile among Mesozoic mammals.
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luo-lab.uchicago.edu
504 Citations
Highly Influential Citations
14
Background Citations
154
Methods Citations
8
Results Citations
8

504 Citations

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107 References

Molecular evidence for the early divergence of placental mammals.

The adaptive diversification of placental mammals may have required the demise of the dinosaurs at the end of the Cretaceous, but it occurred in lineages that had a long prior history of independent existence.

An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution

New data from this fossil support the view that Asia was likely the center for the diversification of the earliest metatherians and eutherians during the Early Cretaceous.

The delayed rise of present-day mammals

The results show that the phylogenetic ‘fuses’ leading to the explosion of extant placental orders are not only very much longer than suspected previously, but also challenge the hypothesis that the end-Cretaceous mass extinction event had a major, direct influence on the diversification of today’s mammals.

Evolutionary and preservational constraints on origins of biologic groups: divergence times of eutherian mammals.

Molecular clock estimates of divergence times of taxonomic groups undergoing evolutionary radiation are much older than the groups' first observed fossil record, suggesting that it is unlikely that many modern orders arose much earlier than their oldest fossil records.

A Late Jurassic Digging Mammal and Early Mammalian Diversification

Parsimony analysis suggests that this fossil represents a separate basal mammalian lineage with some dental and vertebral convergences to those of modern xenarthran placentals, and reveals a previously unknown ecomorph of early mammals.

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A fossil from the Early Jurassic represents a new lineage of mammaliaforms, the extinct groups more closely related to the living mammals than to nonmammaliaform cynodonts, and shows that several key mammalian evolutionary innovations in the ear region, the temporomandibular joint, and the brain vault evolved incrementally through mammaliaform evolution and long before the differentiation of the living mammal groups.

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This fossil demonstrates that some mammaliaforms, or proximal relatives to modern mammals, developed diverse locomotory and feeding adaptations and were ecomorphologically different from the majority of generalized small terrestrial Mesozoic mammalian insectivores.

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Although the fossil record is incomplete, it appears adequate to reject the hypothesis that orders of placentals began to diversify before the K/T boundary; thus, early Tertiary ordinal diversification is real.
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