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

  title={A Swimming Mammaliaform from the Middle Jurassic and Ecomorphological Diversification of Early Mammals},
  author={Qiang Ji and Zhe‐Xi Luo and Chong-xi Yuan and Alan R. Tabrum},
  pages={1123 - 1127}
A docodontan mammaliaform from the Middle Jurassic of China possesses swimming and burrowing skeletal adaptations and some dental features for aquatic feeding. It is the most primitive taxon in the mammalian lineage known to have fur and has a broad, flattened, partly scaly tail analogous to that of modern beavers. We infer that docodontans were semiaquatic, convergent to the modern platypus and many Cenozoic placentals. This fossil demonstrates that some mammaliaforms, or proximal relatives to… 
An arboreal docodont from the Jurassic and mammaliaform ecological diversification
A new docodontan mammaliaform from the Middle Jurassic of China has skeletal features for climbing and dental characters indicative of an omnivorous diet that included plant sap, revealing a greater ecological diversity in an early mammaliaforms clade at a more fundamental taxonomic level not only between major clades as previously thought.
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.
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.
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
New gliding mammaliaforms from the Jurassic
Two new eleutherodonts from the Late Jurassic period have skin membranes and skeletal features that are adapted for gliding, and show an evolutionary experimentation similar to the iterative evolutions of gliders within arboreal groups of marsupial and placental mammals.
A Mesozoic gliding mammal from northeastern China
A new Mesozoic mammal from Inner Mongolia, China, is reported that represents a previously unknown group characterized by a highly specialized insectivorous dentition and a sizable patagium (flying membrane) for gliding flight.
New Jurassic mammaliaform sheds light on early evolution of mammal-like hyoid bones
A Jurassic fossil shows that early premammalian ancestors possessed hyoids similar to those seen in mammals today, and a new Jurassic docodontan mammaliaform found in China that is preserved with the hyoid bones is reported.
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.
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.


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 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 Middle Jurassic mammal from Madagascar
The lower molars of tribosphenic mammals (marsupials, placentals and their extinct allies) are marked, primitively, by a basined heel (talonid) acting as the mortar to the pestle of a large inner
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.
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.
Dental Morphology of the Jurassic Holotherian Mammal Amphitherium, with a Discussion of the Evolution of Mammalian Post‐Canine Dental Formulae
It is concluded that Amphitherium probably had reached the grade of modern therians in the division between diphyodont premolars and monophyodont molars, and probably was secondarily increased in the number of molars.
A new maniraptoran dinosaur from China with long feathers on the metatarsus
A new eumaniraptoran theropod from China, with avian affinities, is reported, which also has long pennaceous feathers on its feet, suggesting that such morphology might represent a primitive adaptation close to the theropOD–bird transition.
Abstract Tashkumyrodon desideratus, gen. et sp. nov. from the Middle Jurassic (Callovian) Balabansai Formation near Tashkumyr in Kyrgyzstan is described from a single lower molar. The tooth exhibits
A new docodont mammal from the Late Jurassic of the Junggar Basin in Northwest China
Fieldwork in the early Late Jurassic (Oxfordian) Qigu Formation of the Junggar Basin in Northwest China (Xinjiang Au− tonomous Region) produced teeth and mandibular fragments of a new docodont. The
Locomotor evolution in the earliest cetaceans: functional model, modern analogues, and paleontological evidence
It is concluded that Ambulocetus may have locomoted by a combination of pelvic paddling and dorsoventral undulations of the tail, and that its locomotor mode in water resembled that of the modern otter Lutra most closely.