Amphibia

Berkovitz, Β.Κ.B.

doi:10.1016/b978-0-12-802850-6.00005-9

Cited by 2 publications

(2 citation statements)

References 54 publications

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“…The jaw skeleton and the dentition are both impressively adaptable to a broad range of diets and feeding strategies [ 3 ]. Teeth and the jaws that house them also show substantial developmental lability: they may develop, and evolve, in very different ways and in isolation of each other [ 3 , 4 , 5 ]. Grappling with this paradox of evo-devo synchrony and sovereignty is vital to clarify the mechanisms that generate animal diversity of the face and teeth.…”

Section: Introductionmentioning

confidence: 99%

Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

Kelly

Thompson

et al. 2021

JDB

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For humans and other mammals to eat effectively, teeth must develop properly inside the jaw. Deciphering craniodental integration is central to explaining the timely formation of permanent molars, including third molars which are often impacted in humans, and to clarifying how teeth and jaws fit, function and evolve together. A factor long-posited to influence molar onset time is the jaw space available for each molar organ to form within. Here, we tested whether each successive molar initiates only after a minimum threshold of space is created via jaw growth. We used synchrotron-based micro-CT scanning to assess developing molars in situ within jaws of C57BL/6J mice aged E10 to P32, encompassing molar onset to emergence. We compared total jaw, retromolar and molar lengths, and molar onset times, between upper and lower jaws. Initiation time and developmental duration were comparable between molar upper and lower counterparts despite shorter, slower-growing retromolar space in the upper jaw, and despite size differences between upper and lower molars. Timing of molar formation appears unmoved by jaw length including space. Conditions within the dental lamina likely influence molar onset much more than surrounding jaw tissues. We theorize that molar initiation is contingent on sufficient surface area for the physical reorganization of dental epithelium and its invagination of underlying mesenchyme.

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Section: Introductionmentioning

confidence: 99%

Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

Kelly

Thompson

et al. 2021

JDB

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“…Ctenosaura , Cyclura , Iguana ) indicating broad similarities in snout morphology (figure 4). This convergence may represent a reptilian version of an emphasis on increased oral processing, given that iguanids possess a greater number of teeth relative to most other lepidosaurs [84]. It should be noted, however, that some omnivorous and insectivorous mammals and squamates also fall into this range, and there is less overlap in the lateral view dataset.…”

Section: Discussionmentioning

confidence: 99%

The limits of convergence: the roles of phylogeny and dietary ecology in shaping non-avian amniote crania

et al. 2021

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Cranial morphology is remarkably varied in living amniotes and the diversity of shapes is thought to correspond with feeding ecology, a relationship repeatedly demonstrated at smaller phylogenetic scales, but one that remains untested across amniote phylogeny. Using a combination of morphometric methods, we investigate the links between phylogenetic relationships, diet and skull shape in an expansive dataset of extant toothed amniotes: mammals, lepidosaurs and crocodylians. We find that both phylogeny and dietary ecology have statistically significant effects on cranial shape. The three major clades largely partition morphospace with limited overlap. Dietary generalists often occupy clade-specific central regions of morphospace. Some parallel changes in cranial shape occur in clades with distinct evolutionary histories but similar diets. However, members of a given clade often present distinct cranial shape solutions for a given diet, and the vast majority of species retain the unique aspects of their ancestral skull plan, underscoring the limits of morphological convergence due to ecology in amniotes. These data demonstrate that certain cranial shapes may provide functional advantages suited to particular dietary ecologies, but accounting for both phylogenetic history and ecology can provide a more nuanced approach to inferring the ecology and functional morphology of cryptic or extinct amniotes.

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Amphibia

Cited by 2 publications

References 54 publications

Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

The limits of convergence: the roles of phylogeny and dietary ecology in shaping non-avian amniote crania

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