An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution

@article{Luo2003AnEC,
  title={An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution},
  author={Zhe‐Xi Luo and Qiang Ji and John R. Wible and Chong-xi Yuan},
  journal={Science},
  year={2003},
  volume={302},
  pages={1934 - 1940},
  url={https://api.semanticscholar.org/CorpusID:18032860}
}
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.
View on AAAS
luo-lab.uchicago.edu
358 Citations
Highly Influential Citations
38
Background Citations
139
Methods Citations
5
Results Citations
9

358 Citations

A Jurassic eutherian mammal and divergence of marsupials and placentals

This mammal has scansorial forelimb features, and provides the ancestral condition for dental and other anatomical features of eutherians, reducing and resolving a discrepancy between the previous fossil record and the molecular estimate for the placental–marsupial divergence.

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.

A Swimming Mammaliaform from the Middle Jurassic and Ecomorphological Diversification of Early Mammals

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.

A stagodontid mammal from the mid-Cretaceous of France confirms the Euramerican distribution of early marsupialiforms

Marsupials and Other Metatheres of South America

The carnivorous sparassodonts evolved the largest metatherian predators known, such as the 600 kg Proborhyaena, as well as the jaguar-sized saber-toothed marsupial Thylacosmilus.

A Cretaceous symmetrodont therian with some monotreme-like postcranial features

Analysis including this new taxon suggests that spalacotheroids evolved earlier in Eurasia and then dispersed to North America, in concordance with prevailing geodispersal patterns of several common mammalian groups during the Early Cretaceous period.

New basal eutherian mammal from the Early Cretaceous Jehol biota, Liaoning, China

The morphological differences between Acristatherium and Eomaia indicate that eutherians already had a significant degree of generic diversification ca 125 Ma, and place A. yanensis as the most basal eutherian in the selected group.

An Early Cretaceous eutherian and the placental–marsupial dichotomy

Morphological studies and phylogenetic analyses based on the newly discovered Early Cretaceous eutherian mammal Ambolestes zhoui show that the oldest purported metatherian Sinodelphys is instead a eutheria, and that postcranial differences between Sinodelsphys and the Jehol eutherians Eomaia are instead variations among the early members of the placental lineage.

The origin and early evolution of metatherian mammals: the Cretaceous record

Metatherian diversification patterns suggest that they were not strongly affected by a Cretaceous Terrestrial Revolution, but they clearly underwent a severe extinction across the K-Pg boundary.

The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography

The main significance of the Archingeay-Les Nouillers mammal discovery is that it indicates that the beginning of the stem marsupialiforms history involved not only North America but also Europe, and that this early history in Europe remains virtually unknown.
...

47 References

The earliest known eutherian mammal

The skeleton of a eutherian (placental) mammal found in northeastern China has limb and foot features that are known only from scansorial and arboreal extant mammals, in contrast to the terrestrial or cursorial features of other Cretaceous eutherians.

Tribosphenic mammal from the North American Early Cretaceous

A new tribosphenic mammal from the Early Cretaceous of North America is described, based on an unusually complete specimen, and its molar structure is primitive, emphasizing the need for caution in interpretation of isolated teeth.

Dual origin of tribosphenic mammals

Phylogenetic and morphometric analyses including these newly discovered taxa suggest a different interpretation: that mammals with tribosphenic molars are not monophyletic.

A new symmetrodont mammal from China and its implications for mammalian evolution

This analysis suggests that this new taxon represents a part of the early therian radiation before the divergence of living marsupials and placentals; that therians and multituberculates are more closely related to each other than either group is to other mammalian lineages.

Implications of Deltatheridium specimens for early marsupial history

The presence of specialized marsupial patterns of tooth replacement and cranial vascularization in Deltatheridium and the basal phylogenetic position of this taxon indicate that these features are characteristic of Metatheria as a whole.

A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton

The derived pectoral girdle of this new triconodont indicates that homoplasies are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals.

Late Cretaceous relatives of rabbits, rodents, and other extant eutherian mammals

It is argued that some Late Cretaceous eutherian eutherians belong within the crown group Placentalia, and the ages of these taxa are in line with molecularly based estimates for the superordinal diversification of some placentals, but provide no support for the Late CRETaceous diversifying of extant placental orders.

Eutherian mammals from the Early Cretaceous of Mongolia

A collection of eutherian mammals consisting of 39 specimens (teeth and jaw fragments) from the ?Aptian or Albian Khoboor Beds in the Gobi Desert, Mongolia, is described. It contains 3 taxa:…

The origin of the dog-like borhyaenoid marsupials of South America

Comparison of the skulls of Mayulestes, Andinodelphys and Pucadelphys, from the early Palaeocene epoch of Bolivia are the oldest known for American marsupials and basicranial anatomy suggests that dog-like marsupial are closely related to an early didelphimorphian radiation in South America, rather than to Asiatic, North American, North America, or Australian lineages.

A morphological analysis of marsupial mammal higher-level phylogenetic relationships