Jaw musculature during the dawn of turtle evolution

Using a new approach to study muscle anatomy in vertebrates, the fully differentiated jaw musculature of 42 turtle species was studied and character mappings were performed. Soft tissue arrangements were correlated to the temporal openings (emarginations) of the skull and the trochlearis system of the jaw apparatus among turtle taxa. When compared to the cranial anatomy of stem Testudines, most characters detected as diagnostic of particular extant groups have to be considered as being evolved first within Testudines. Hence, jaw muscle anatomy of extant turtles is difficult to compare to that of other reptilian taxa. Moreover, the high number of apomorphic character changes speaks for a divergating turtle and saurian morphotype of jaw musculature, which could indicate either a position of turtles outside of Sauria or a highly derived, undetectable origin within that group. In general, a low direct correlation of most soft and hard tissue characters was detected. This finding could imply that both character complexes are more integrated to each other driven by functional morphology; i.e., the composition of muscle fibre types. That condition highlights the difficulty in using gross anatomy of jaw muscle characters to interpret temporal bone arrangements among amniotes in genera

Training Neural Networks Using Reproducing Kernel Space Interpolation and Model Reduction

We introduce and study the theory of training neural networks using interpolation techniques from reproducing kernel Hilbert space theory. We generalize the method to Krein spaces, and show that widely-used neural network architectures are subsets of reproducing kernel Krein spaces (RKKS). We study the concept of "associated Hilbert spaces" of RKKS and develop techniques to improve upon the expressivity of various activation functions. Next, using concepts from the theory of functions of several complex variables, we prove a computationally applicable, multidimensional generalization of the celebrated Adamjan- Arov-Krein (AAK) theorem. The theorem yields a novel class of neural networks, called Prolongation Neural Networks (PNN). We demonstrate that, by applying the multidimensional AAK theorem to gain a PNN, one can gain performance superior to both our interpolatory methods and current state-of-the-art methods in noisy environments. We provide useful illustrations of our methods in practice

A Daughter\u27s Struggle to Individuate in Einstein\u27s Daughter

Claudia Smith Brinson’s short story, “Einstein’s Daughter,” is a coming of age tale about a young girl who must delicately navigate her relationship with her mother in order gain independence. The protagonist, who narrates the story, remains unnamed and is defined mostly in reference to her mother’s lineage. The narrator begins the story with the concept that one’s biologically inherited character traits largely determine one’s future. Alluding to Einstein’s theory of relativity, the protagonist uses her extraordinary speed to travel back in time and explore the previous three generations of families on her mother’s side. She uses her observations to plot the probabilities of her own future based on the characteristics and lives of her predecessors. The protagonist’s struggle for autonomy demonstrates how mother-daughter relationships perpetuate patriarchal gender roles, which inherently marginalize women. Additionally, the protagonist’s flight at the story’s end suggests that women must reject biological essentialism and individuate from their mothers in order to create a sense of self that deviates from patriarchal norms

Encountering the Phantasmagoria: Pre-Raphaelite Aesthetics as the Antidote for Victorian Decadence in Robert Browning’s “My Last Duchess”

Robert Browning’s “My Last Duchess” engages with ‘the problem of Raphael,’ a Victorian aesthetic debate into which Browning enters in order to address Victorian society’s spiritual impotence, which he connects to the societal emphasis on external appearances of virtue and nobility. This emphasis on appearances is reflected in Raphaelite aesthetics, for Victorians understood Raphael’s paintings as representational pictures intended to cause viewers to contemplate spiritual states. The Raphaelite school of aesthetics saw Raphael’s works as the pinnacle of the Christian visual art tradition, while the pre-Raphaelites sought to dissolve the distinction between sacred and secular, painting human bodies as they actual appear, with all of their awkward flaws, as opposed to the polished, perfected, demigod-like humans in a Raphael. This essay weaves Baudelaire’s aesthetic theory of the phantasmagoria with the Victorian aesthetic debate over the problem of Raphael, and the pre-Raphaelite school of Victorian painters’ associations with sacramental realism, for a new take on Robert Browning’s “My Last Duchess.

Domestication and the comparative embryology of birds

Studies of domesticated animals have greatly contributed to our understanding of avian embryology. Foundational questions in developmental biology were motivated by Aristotle's observations of chicken embryos. By the 19th century, the chicken embryo was at the center stage of developmental biology, but how closely does this model species mirror the ample taxonomic diversity that characterizes the avian tree of life? Here, we provide a brief overview of the taxonomic breadth of comparative embryological studies in birds. We particularly focused on staging tables and papers that attempted to document the timing of developmental transformations. We show that most of the current knowledge of avian embryology is based on Galliformes (chicken and quail) and Anseriformes (duck and goose). Nonetheless, data are available for some ecologically diverse avian subclades, including Struthioniformes (e.g., ostrich, emu) and Sphenisciformes (penguins). Thus far, there has only been a handful of descriptive embryological studies in the most speciose subclade of Aves, that is, the songbirds (Passeriniformes). Furthermore, we found that temporal variances for developmental events are generally uniform across a consensus chronological sequence for birds. Based on the available data, developmental trajectories for chicken and other model species appear to be highly similar. We discuss future avenues of research in comparative avian embryology in light of the currently available wealth of data on domesticated species and beyond.info:eu-repo/semantics/publishedVersio

Timing of organogenesis support basal position of turtles in the amniote tree of life

Background: The phylogenetic position of turtles is the most disputed aspect in the reconstruction of the land vertebrate tree of life. This controversy has arisen after many different kinds and revisions of investigations of molecular and morphological data. Three main hypotheses of living sister-groups of turtles have resulted from them: all reptiles, crocodiles + birds or squamates + tuatara. Although embryology has played a major role in morphological studies of vertebrate phylogeny, data on developmental timing have never been examined to explore and test the alternative phylogenetic hypotheses. We conducted a comprehensive study of published and new embryological data comprising 15 turtle and eight tetrapod species belonging to other taxa, integrating for the first time data on the side-necked turtle clade. Results: The timing of events in organogenesis of diverse character complexes in all body regions is not uniform across amniotes and can be analysed using a parsimony-based method. Changes in the relative timing of particular events diagnose many clades of amniotes and include a phylogenetic signal. A basal position of turtles to the living saurian clades is clearly supported by timing of organogenesis data. Conclusion: The clear signal of a basal position of turtles provided by heterochronic data implies significant convergence in either molecular, adult morphological or developmental timing characters, as only one of the alternative solutions to the phylogenetic conundrum can be right. The development of a standard reference series of embryological events in amniotes as presented here should enable future improvements and expansion of sampling and thus the examination of other hypotheses about phylogeny and patterns of the evolution of land vertebrate development

Palate anatomy and morphofunctional aspects of interpterygoid vacuities in temnospondyl cranial evolution

Temnospondyls were the morphologically and taxonomically most diverse group of early tetrapods with a near-global distribution during the Palaeozoic and Mesozoic. Members of this group occupied a range of different habitats (aquatic, amphibious, terrestrial), reflected by large morphological disparity of the cranium throughout their evolutionary history. A diagnostic feature of temnospondyls is the presence of an open palate with large interpterygoid vacuities, in contrast to the closed palate of most other early tetrapods and their fish-like relatives. Although the function of the interpterygoid vacuities has been discussed in the past, no quantitative studies have been performed to assess their biomechanical significance. Here, we applied finite element analysis, to test the possibility that the interpterygoid vacuities served for stress distribution during contraction of the jaw closing musculature. Different original and theoretical skull models, in which the vacuities differed in size or were completely absent, were compared for their mechanical performance. Our results demonstrate that palatal morphology played a considerable role in cranial biomechanics of temnospondyls. The presence of large cranial vacuities were found to offer the dual benefit of providing additional muscle attachment areas and allowing for more effective force transmission and thus an increase in bite force without compromising cranial stability

3D model related to the publication: The endocranial anatomy of the stem turtle Naomichelys speciosa from the Early Cretaceous of North America

The present 3D Dataset contains the 3D model analyzed in the following publication: Paulina-Carabajal, A., Sterli, J., Werneburg, I., 2019. The endocranial anatomy of the stem turtle Naomichelys speciosa from the Early Cretaceous of North America. Acta Palaeontologica Polonica, https://doi.org/10.4202/app.00606.2019.Fil: Paulina Carabajal, Ariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Sterli, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Werneburg, Ingmar. Eberhard Karls Universität Tübingen; Alemani

Les Amphibiens branchiosauridés du Permien inférieur de Buxières-les-Mines, bassin de Bourbon l’Archambault (Allier, France) et sa signification biostratigraphique

Les Branchiosauridés sont rares dans la faune lacustre du Permien inférieur de Buxières-les-Mines, bassin de Bourbon l’Archambault (Massif central, Allier, France). Tous les spécimens connus appartiennent à Melanerpeton gracile qui est caractéristique de la zone à Melanerpeton gracile-Discosauriscus pulcherrimus issue de l’échelle biostratigraphique basée sur les amphibiens aquatiques du Carbonifère supérieur et du Permien inférieur. Cette espèce de branchiosauridés permet l’attribution d’un âge assélien (juste au dessus de “l’Autunien inférieur”/Rotliegend) pour la série des schistes bitumineux de Buxières-les-Mines appartenant à l’assise de Buxières du bassin de Bourbon l’Archambault (Allier, France)