المؤلفون: Newham E; School of Engineering and Materials Science, Queen Mary University of London, London, UK.; Department of Palaeontology, Institute for Geosciences, University of Bonn, Bonn, Germany., Gill PG; School of Earth Sciences, University of Bristol, Bristol, UK.; Earth Sciences Department, Natural History Museum, London, UK., Corfe IJ; Jernvall Laboratory, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.; Geological Survey of Finland, Espoo, Finland.

المصدر: BioEssays : news and reviews in molecular, cellular and developmental biology [Bioessays] 2022 Apr; Vol. 44 (4), pp. e2100060. Date of Electronic Publication: 2022 Feb 16.

نوع المنشور: Journal Article

بيانات الدورية: Publisher: Wiley Country of Publication: United States NLM ID: 8510851 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1521-1878 (Electronic) Linking ISSN: 02659247 NLM ISO Abbreviation: Bioessays Subsets: MEDLINE

مواضيع طبية MeSH: Biological Evolution* , Mammals*/physiology, Animals ; Fossils ; Phylogeny

مستخلص: We suggest that mammalian endothermy was established amongst Middle Jurassic crown mammals, through reviewing state-of-the-art fossil and living mammal studies. This is considerably later than the prevailing paradigm, and has important ramifications for the causes, pattern, and pace of physiological evolution amongst synapsids. Most hypotheses argue that selection for either enhanced aerobic activity, or thermoregulation was the primary driver for synapsid physiological evolution, based on a range of fossil characters that have been linked to endothermy. We argue that, rather than either alternative being the primary selective force for the entirety of endothermic evolution, these characters evolved quite independently through time, and across the mammal family tree, principally as a response to shifting environmental pressures and ecological opportunities. Our interpretations can be tested using closely linked proxies for both factors, derived from study of fossils of a range of Jurassic and Cretaceous mammaliaforms and early mammals.
(© 2022 The Authors. BioEssays published by Wiley Periodicals LLC.)

المؤلفون: Lautenschlager S; School of Earth Sciences, University of Bristol, Bristol, UK. s.lautenschlager@bham.ac.uk.; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK. s.lautenschlager@bham.ac.uk., Gill PG; School of Earth Sciences, University of Bristol, Bristol, UK.; Earth Science Department, The Natural History Museum, London, UK., Luo ZX; Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA., Fagan MJ; School of Engineering and Computer Science, University of Hull, Hull, UK., Rayfield EJ; School of Earth Sciences, University of Bristol, Bristol, UK. e.rayfield@bristol.ac.uk.

المصدر: Nature [Nature] 2018 Sep; Vol. 561 (7724), pp. 533-537. Date of Electronic Publication: 2018 Sep 17.

نوع المنشور: Journal Article; Research Support, Non-U.S. Gov't

بيانات الدورية: Publisher: Nature Publishing Group Country of Publication: England NLM ID: 0410462 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1476-4687 (Electronic) Linking ISSN: 00280836 NLM ISO Abbreviation: Nature Subsets: MEDLINE

مواضيع طبية MeSH: Biological Evolution*, Ear, Middle/*anatomy & histology , Mammals/*anatomy & histology , Mandible/*anatomy & histology, Animals ; Ear, Middle/physiology ; Fossils ; Mammals/physiology ; Mandible/physiology ; Models, Biological ; Phylogeny ; Temporomandibular Joint/anatomy & histology ; Temporomandibular Joint/physiology ; Tooth/anatomy & histology ; Tooth/physiology

مستخلص: The evolution of the mammalian jaw is one of the most important innovations in vertebrate history, and underpins the exceptional radiation and diversification of mammals over the last 220 million years ^1,2 . In particular, the transformation of the mandible into a single tooth-bearing bone and the emergence of a novel jaw joint-while incorporating some of the ancestral jaw bones into the mammalian middle ear-is often cited as a classic example of the repurposing of morphological structures ^3,4 . Although it is remarkably well-documented in the fossil record, the evolution of the mammalian jaw still poses the paradox of how the bones of the ancestral jaw joint could function both as a joint hinge for powerful load-bearing mastication and as a mandibular middle ear that was delicate enough for hearing. Here we use digital reconstructions, computational modelling and biomechanical analyses to demonstrate that the miniaturization of the early mammalian jaw was the primary driver for the transformation of the jaw joint. We show that there is no evidence for a concurrent reduction in jaw-joint stress and increase in bite force in key non-mammaliaform taxa in the cynodont-mammaliaform transition, as previously thought ^5-8 . Although a shift in the recruitment of the jaw musculature occurred during the evolution of modern mammals, the optimization of mandibular function to increase bite force while reducing joint loads did not occur until after the emergence of the neomorphic mammalian jaw joint. This suggests that miniaturization provided a selective regime for the evolution of the mammalian jaw joint, followed by the integration of the postdentary bones into the mammalian middle ear.