A new eutriconodont mammal and evolutionary development in early mammals

@article{Luo2007ANE,
  title={A new eutriconodont mammal and evolutionary development in early mammals},
  author={Z. Luo and P. Chen and Gang Li and Meng Chen},
  journal={Nature},
  year={2007},
  volume={446},
  pages={288-293}
}
Detachment of the three tiny middle ear bones from the reptilian mandible is an important innovation of modern mammals. Here we describe a Mesozoic eutriconodont nested within crown mammals that clearly illustrates this transition: the middle ear bones are connected to the mandible via an ossified Meckel’s cartilage. The connected ear and jaw structure is similar to the embryonic pattern in modern monotremes (egg-laying mammals) and placental mammals, but is a paedomorphic feature retained in… Expand

Paper Mentions

Blog Post
Evolutionary Development of the Middle Ear in Mesozoic Therian Mammals
TLDR
A Cretaceous trechnotherian mammal with an ossified Meckel’s cartilage in the adult is reported, showing that homoplastic evolution of the DMME occurred in derived therian mammals, besides the known cases of eutriconodonts. Expand
A Cretaceous eutriconodont and integument evolution in early mammals
TLDR
A 125-million-year-old eutriconodontan mammal from Spain with extraordinary preservation of skin and pelage that extends the record of key mammalian integumentary features into the Mesozoic era is reported. Expand
Transitional mammalian middle ear from a new Cretaceous Jehol eutriconodont
TLDR
This transitional mammalianmiddle ear narrows the morphological gap between the mandibular middle ear in basal mammaliaforms and the definitive mammalian middle ear of extant mammals; it reveals complex changes contributing to the detachment of ear ossicles during mammalian evolution. Expand
Evolution of the Middle and Inner Ears of Mammaliaforms: The Approach to Mammals
TLDR
The homoplasies of ear structures in early mammalian evolution, although seemingly complex, are consistent with the new understanding of a labile morphogenesis of mammalian ears under a complex developmental genetic network. Expand
Exploring ancestral phenotypes and evolutionary development of the mammalian middle ear based on Early Cretaceous Jehol mammals
We report a new Cretaceous multituberculate mammal with 3D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentiallyExpand
Mammalian development does not recapitulate suspected key transformations in the evolutionary detachment of the mammalian middle ear
TLDR
It is shown that neither allometric nor topological change is quantifiable in the pre-detachment ME development of six marsupials and two monotremes, and this challenges the developmental prerequisites of widely cited evolutionary scenarios of definitive mammalian middle ear (DMME) evolution. Expand
A Jurassic mammaliaform and the earliest mammalian evolutionary adaptations
TLDR
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. Expand
Mammalian evolution: A jaw-dropping ear
TLDR
A fossil from the Early Cretaceous provides insight into the evolution of the hearing apparatus in mammals and shows that Meckel's cartilage was a vital piece in the evolutionary jigsaw that led to the formation of the mammalian middle ear. Expand
Convergent dental adaptations in pseudo-tribosphenic and tribosphenic mammals
TLDR
The find reveals a much greater range of dental evolution in Mesozoic mammals than in their extant descendants, and strengthens the hypothesis of homoplasy of ‘tribosphenic-like’ molars among mammals. Expand
New evidence for mammaliaform ear evolution and feeding adaptation in a Jurassic ecosystem
TLDR
A new Jurassic eleutherodontid mammaliaform with an unusual mosaic of highly specialized characteristics is reported, and the results of phylogenetic analyses support the hypothesis that haramiyidans are stem mammaliaforms. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 65 REFERENCES
A New Mammaliaform from the Early Jurassic and Evolution of Mammalian Characteristics
TLDR
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. Expand
A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton.
TLDR
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. Expand
Cranial Morphology of the Therian Common Ancestor, as Suggested by the Adaptations of Neonate Marsupials
TLDR
Whereas early skull development in marsupials is characterized by a number of narrow functional and biological constraints resulting in a certain structural uniformity, the eutherian mode of development seems to provide more freedom for fetal differentiation. Expand
A new symmetrodont mammal from China and its implications for mammalian evolution
TLDR
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. Expand
Ontogenetic and phylogenetic transformations of the ear ossicles in marsupial mammals
This study is based on the examination of histological sections of specimens of different ages and of adult ossicles from macerated skulls representing a wide range of taxa and aims at addressingExpand
Phylogeny and Ontogeny of Mammalian Middle Ear Structures
TLDR
Fossil finds of advanced cynodonts and early mammals demonstrate that within the synapsids a new sound transforming system evolved at the posterior angle of the mandible, which is most probably not homologous to that of sauropsids. Expand
Comment on "Independent Origins of Middle Ear Bones in Monotremes and Therians" (II)
TLDR
The malleus has been independently freed from the dentary in monotremes and in therians and acknowledge that BEa^ssertions of fundamental differences in development and morphology between monotreme and therian ears are no longer supported and fossils like Teinolophos are the only potential sources of conflict. Expand
PALEONTOLOGY: Homoplasy in the Mammalian Ear.
TLDR
A new fossil-the dentary bone of an ancient toothed monotreme-suggests that the middle ear bones formed independently in these two mammalian lineages, providing a remarkable example of homoplastic evolution. Expand
A Cretaceous symmetrodont therian with some monotreme-like postcranial features
TLDR
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. Expand
Homoplasy in the Mammalian Ear
TLDR
A new fossil-the dentary bone of an ancient toothed monotreme-suggests that the middle ear bones formed independently in these two mammalian lineages, providing a remarkable example of homoplastic evolution. Expand
...
1
2
3
4
5
...