The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals

  title={The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals},
  author={Tomasz Sulej and Grzegorz Krzesinski and Mateusz Tałanda and Andrzej S Wolniewicz and Błażej Błażejowski and Niels Bonde and Piotr Gutowski and Maksymilian Sienkiewicz and Grzegorz Niedźwiedzki},
  journal={Proceedings of the National Academy of Sciences},
  pages={26861 - 26867}
Significance Mammals underwent an adaptive radiation shortly after the acquisition of several morphological characters in their dentition and jaw. Most of these innovations evolved to facilitate more efficient food processing. The double-rooted molariforms with a specialized crown are one such innovation, but their role in the early diversification of mammals has remained poorly understood. This study shows a comprehensive analysis of an early mammaliaform dentary, which combines data from… 
The evolution of anteriorly directed molar occlusion in mammals
It is posited that therian mammals (eutherians and metatherians) evolved anteriorly directed chewing strokes, which are absent in other synapsid lineages, and this evolutionary transition might have been a crucial prerequisite for the dietary diversification of therians.
Issi saaneq gen. et sp. nov.—A New Sauropodomorph Dinosaur from the Late Triassic (Norian) of Jameson Land, Central East Greenland
The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in
Symmetry and Aesthetics in Dentistry
Animal bodies in general and faces in particular show mirror symmetry with respect to the median-sagittal plane, with exceptions rarely occurring. Bilateral symmetry to the median sagittal plane of


Dietary specializations and diversity in feeding ecology of the earliest stem mammals
An integrated analysis using synchrotron X-ray tomography and analyses of biomechanics, finite element models and tooth microwear textures reveals previously hidden trophic specialization at the base of the mammalian radiation; hence even the earliest mammaliaforms were beginning to diversify—morphologically, functionally and ecologically.
Mandibular and dental characteristics of Late Triassic mammaliaform Haramiyavia and their ramifications for basal mammal evolution
Tests of competing phylogenetic hypotheses with new data show that Late Triassic haramiyids are a separate clade from multituberculate mammals and are excluded from the Mammalia, suggesting that dietary diversification is a major factor in the earliest mammaliaform evolution.
New evidence for mammaliaform ear evolution and feeding adaptation in a Jurassic ecosystem
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.
Late-surviving stem mammal links the lowermost Cretaceous of North America and Gondwana
It is suggested that hahnodontid mammaliaforms had a much wider, possibly Pangaean distribution during the Jurassic–Cretaceous transition, and an exceptionally preserved skull of Cifelliodon wahkarmoosuch sheds light on the evolution of the ancestral mammalian brain.
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.
Haramiyids and Triassic mammalian evolution
The discovery of haramiyid dentaries, a maxilla and other skeletal remains in the Upper Triassic of East Greenland revealsHaramiyids as highly specialized mammals with a novel pattern of puncture-crushing occlusion that differs dramatically from the grinding or shearing mechanisms of other Early Mesozoic mammals.
Jurassic stem-mammal perinates and the origin of mammalian reproduction and growth
A well-preserved clutch of Kayentatherium wellesi perinates sheds light on the timing of the evolution of mammalian traits, including reduced clutch sizes and the allometric lengthening of the face during ontogeny.
The jaw articulation of the Docodonta and the classification of Mesozoic mammals
  • K. Kermack, F. Mussett
  • Geology, Medicine
    Proceedings of the Royal Society of London. Series B - Biological Sciences
  • 1958
Comparison with the most advanced of the mammal-like reptiles shows that this groove must have been for the malleus (articular), which in Docodon and in Morganucodon still functioned as part of the jaw articulation, although in both the main part of this hinge would have been formed by the well-developed mammalian condyle on the back end of the dentary.
Definition, diagnosis, and origin of Mammalia
Triassic and Early Jurassic taxa commonly referred to as mammals, including Morganucodontidae, Kuehneotheriidae, and Haramiyidae, were found to lie outside of Mammalia.
Review of the early allotherian mammals
It is postulated that allotherian and non-allotherian mammaliaform clades separated before the Mammaliaformes developed a shearing dentition with unilateral occlusion and transverse jaw movements, to account for the apparent synapomorphies of multituberculates and therians.