A Late Jurassic Digging Mammal and Early Mammalian Diversification

  title={A Late Jurassic Digging Mammal and Early Mammalian Diversification},
  author={Zhe‐Xi Luo and John R. Wible},
  pages={103 - 107}
A fossil mammal from the Late Jurassic Morrison Formation, Colorado, has highly specialized teeth similar to those of xenarthran and tubulidentate placental mammals and different from the generalized insectivorous or omnivorous dentitions of other Jurassic mammals. It has many forelimb features specialized for digging, and its lumbar vertebrae show xenarthrous articulations. Parsimony analysis suggests that this fossil represents a separate basal mammalian lineage with some dental and vertebral… 

A Jurassic mammaliaform and the earliest mammalian evolutionary adaptations

A new fossil from the Middle Jurassic that has a mandibular middle ear, a gradational transition of thoracolumbar vertebrae and primitive ankle features, but highly derived molars with a high crown and multiple roots that are partially fused is described.

Modern Data on the Origin and Early Radiation of Mammals

New paleontological and embryological data on the morphogenesis of the auditory ossicles demonstrate parallel developments of the definitive mammal middle ear in the placentals, marsupials, and monotremes, as well as the independent origins of a number of early groups.

Mammals that coexisted with dinosaurs

Seven fossil sites of Mesozoic mammals have been discovered in Russia: four in Western Siberia (one Middle Jurassic and three Early Cretaceous), one in European Russia (Middle Jurassic), one in

Evolutionary development in basal mammaliaforms as revealed by a docodontan

It is argued that these morphogenetic mechanisms ofmodern mammals were operating before the rise of modern mammals, driving the morphological disparity in the earliest mammaliaform diversification.

Three new Jurassic euharamiyidan species reinforce early divergence of mammals

The phylogeny suggests that allotherian mammals evolved from a Late Triassic Haramiyavia-like ancestor and diversified into euharamiyidans and multituberculates with a cosmopolitan distribution, implying homologous acquisition of many craniodental and postcranial features in the two groups.

Palaeobiogeography of mesozoic mammals - revisited

The fossil record of mammals in the Mesozoic is decidedly meagre in comparison to that of the Cainozoic, but some useful generalisations can be drawn about the biogeographic history of this group

Earliest Evolution of Multituberculate Mammals Revealed by a New Jurassic Fossil

A new basal multi is described from a nearly complete skeleton that shows that the underpinnings of these adaptations arose early in the evolution of the order, setting the stage for the major diversification and radiation of the group that came during the Cretaceous and Paleogene.

Transformation and diversification in early mammal evolution

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.

Mesozoic mammals of China: implications for phylogeny and early evolution of mammals

  • J. Meng
  • Environmental Science, Geography
  • 2014
The superb specimens from nearly all major groups of Mesozoic mammals in China provided a great amount of information that contributed to understanding on some major issues in phylogeny and the early evolution of mammals, such as divergences of mammals and the evolution of the mammalian middle ear.

Analysis of Molar Structure and Phylogeny of Docodont Genera

A phylogenetic analysis of 31 dental characters of docodonts (12 genera), plus six outgroups, supports a prior hypothesis that this group dispersed to Gondwana during the Middle Jurassic and hypothesizes that docodons and Late Triassic Tikitherium are sister taxa, and that the Tikitheringium-docodont clade, in turn, is related to the mammaliaforms Woutersia and Delsatia.



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.

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.

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

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.

A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China

A complete specimen of a symmetrodont mammal with well-preserved hairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao, western Liaoning is described, significant for understanding the morphology, osteology, phylogeny and life habits of Mesozoic symmetRodont mammals.

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.

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.

Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure

The Mesozoic Mammals in Space and Time and the Interrelationships of Mesozoics Mammals are studied to understand the distribution and relationships of these animals.

The postcranial skeletons of the Triassic mammals Eozostrodon, Megazostrodon and Erythrotherium.

The purposes of this monograph are to describe the postcranial skeletons of the earliest known mammals, and to probe, in so far as possible by osteological study, biological questions concerning the

Resolution of the Early Placental Mammal Radiation Using Bayesian Phylogenetics

Crown-group Eutheria may have their most recent common ancestry in the Southern Hemisphere (Gondwana), and placental phylogeny is investigated using Bayesian and maximum-likelihood methods and a 16.4-kilobase molecular data set.

In quest for a phylogeny of Mesozoic mammals

A phylogeny of all major groups of Mesozoic mammals based on phylogenetic analyses of 46 taxa and 275 osteological and dental characters, using parsimony methods is proposed, suggesting that the “obtuse−angle symmetrodonts” are paraphyletic, and that they lack reliable and unambiguous synapomorphies.