278 research outputs found

    Diplodus levantinus (Teleostei: Sparidae), una nueva especie de sargo del Mediterráneo sudeste frente a Israel, con una lista de especies y una clave de clasificación de las especies del grupo Diplodus sargus

    Get PDF
    The sea bream Diplodus levantinus n. sp. is described from off the coasts of Israel in the eastern Mediterranean Sea, where it replaces Diplodus sargus (Linnaeus, 1758). The new species is characterized by 11-12 spines and 10-16 soft rays in the dorsal fin, 3 spines and 11-13 soft rays in the anal fin, 15-17 pectoral fin rays, 6-9 + 8-12 gill rakers on the first gill arch, upper and lower jaws with a single row of 4 incisors on each side, followed by a total of 16-19 molariform teeth in the upper jaw and 12-14 molariform teeth in the lower jaw, with the molariforms of the upper jaw separated from the incisors by a wide, toothless gap, and the sides of the body in adults with 8 vertical bars of equal width which are present even in large adults, followed by a broad bar on the caudal peduncle which usually nearly reaches the ventral margin of the caudal peduncle. An updated checklist of the species of the genus Diplodus, and a key to species of the Diplodus sargus species group from the eastern Atlantic and Mediterranean Sea, are presented.El sargo levantino Diplodus levantinus n. sp. se describe a partir de ejemplares de las costas de Israel, en el Mediterráneo oriental, donde reemplaza a Diplodus sargus (Linnaeus, 1758). La nueva especie se caracteriza por: 11-12 espinas y 10-16 radios blandos en la aleta dorsal, 3 espinas y 11-13 radios blandos en la aleta anal, 15-17 radios en las pectorales, 6-9 + 8-12 branquispinas en el primer arco branquial; las mandíbulas superior e inferior con una sola fila de 4 incisivos en cada lado, seguidos por un total de 16-19 molares en la mandíbula superior y 12-14 molares en la mandíbula inferior, con los molares de la mandíbula superior separados de los incisivos por una gran distancia sin dientes; los lados del cuerpo, en los adultos, con 8 bandas verticales de igual anchura, presentes incluso en adultos de gran tamaño, seguidas de una amplia banda en el pedúnculo caudal que, por lo general, casi alcanza el margen ventral del pedúnculo caudal. Se diferencia principalmente de D. sargus por el menor número de dientes molares en las mandíbulas superior e inferior, y por la amplia separación, sin dientes, entre molares e incisivos de la mandíbula superior. Se presenta una lista actualizada de las especies del género Diplodus y una clave para las especies del grupo de especies Diplodus sargus del Atlántico este y el Mediterráneo

    A comparative histological study of the osteoderms in the lizards Heloderma suspectum (Squamata: Helodermatidae) and Varanus komodoensis (Squamata: Varanidae)

    Get PDF
    This is the peer reviewed version of the following article: Kirby, A, Vickaryous, M, Boyde, A, et al. A comparative histological study of the osteoderms in the lizards Heloderma suspectum (Squamata: Helodermatidae) and Varanus komodoensis (Squamata: Varanidae). J Anat. 2020; 00: 1– 9. https://doi.org/10.1111/taja.13156 which has been published in final form at https://doi.org/10.1111/taja.13156

    Cutting the Gordian knot: a historical and taxonomic revision of the Jurassic crocodylomorph Metriorhynchus

    Get PDF
    Figure 3. Metriorhynchus brevirostris holotype MHNG V-2232. A, anterior view; B, posterior view. See text for anatomical abbreviations.Published as part of Young, Mark T., Brignon, Arnaud, Sachs, Sven, Hornung, Jahn J., Foffa, Davide, Kitson, James J. N., Johnson, Michela M. & Steel, Lorna, 2021, Cutting the Gordian knot: a historical and taxonomic revision of the Jurassic crocodylomorph Metriorhynchus, pp. 510-553 in Zoological Journal of the Linnean Society 192 (2) on page 535, DOI: 10.1093/zoolinnean/zlaa092, http://zenodo.org/record/701700

    Evidence of macrophagous teleosaurid crocodylomorphs in the Corallian Group (Oxfordian, Late Jurassic) of the UK

    Get PDF
    Teleosaurids were a group of semi-aquatic crocodylomorphs with a fossil record that spanned the Jurassic Period. In the UK, abundant specimens are known from the Oxford Clay Formation (OCF, Callovian to lower Oxfordian), but are very rare in the Kimmeridge Clay Formation (KCF, Kimmeridgian to lower Tithonian), despite their abundance in some contemporaneous deposits in continental Europe. Unfortunately, due to the paucity of material from the intermediate ‘Corallian Gap’ (middle to upper Oxfordian), we lack an understanding of how and why teleosaurid taxic abundance and diversity declined from the OCF to the KCF. The recognition of an incomplete teleosaurid lower jaw from the Corallian of Weymouth (Dorset, UK) begins to rectify this. The vertically oriented dentition, blunt tooth apices, intense enamel ornamentation that shifts to an anastomosed pattern apically, and deep reception pits on the dentary unambiguously demonstrates the affinity of this specimen with an unnamed sub-clade of macrophagous/durophagous teleosaurids (‘Steneosaurus’ obtusidens + Machimosaurus). The high symphyseal tooth count allows us to exclude the specimen from M. hugii and M. mosae, but in absence of more diagnostic material we cannot unambiguously assign DORCM G.3939 to a more specific level. Nevertheless, this specimen represents the first mandibular material referable to Teleosauridae from the poorly sampled middle-upper Oxfordian time-span in the UK

    Pere Alberch's developmental morphospaces and the evolution of cognition

    Get PDF
    In this article we argue for an extension of Pere Alberch's notion of developmental morphospace into the realm of cognition and introduce the notion of cognitive phenotype as a new tool for the evolutionary and developmental study of cognitive abilities

    Neptunism and transformism:Robert Jameson and other evolutionary theorists in early nineteenth-century Scotland

    Get PDF
    This paper sheds new light on the prevalence of evolutionary ideas in Scotland in the early nineteenth century and establish what connections existed between the espousal of evolutionary theories and adherence to the directional history of the earth proposed by Abraham Gottlob Werner and his Scottish disciples. A possible connection between Wernerian geology and theories of the transmutation of species in Edinburgh in the period when Charles Darwin was a medical student in the city was suggested in an important 1991 paper by James Secord. This study aims to deepen our knowledge of this important episode in the history of evolutionary ideas and explore the relationship between these geological and evolutionary discourses. To do this it focuses on the circle of natural historians around Robert Jameson, Wernerian geologist and professor of natural history at the University of Edinburgh from 1804 to 1854. From the evidence gathered here there emerges a clear confirmation that the Wernerian model of geohistory facilitated the acceptance of evolutionary explanations of the history of life in early nineteenth-century Scotland. As Edinburgh was at this time the most important center of medical education in the English-speaking world, this almost certainly influenced the reception and development of evolutionary ideas in the decades that followed.</p

    Homeotic Evolution in the Mammalia: Diversification of Therian Axial Seriation and the Morphogenetic Basis of Human Origins

    Get PDF
    Despite the rising interest in homeotic genes, little has been known about the course and pattern of evolution of homeotic traits across the mammalian radiation. An array of emerging and diversifying homeotic gradients revealed by this study appear to generate new body plans and drive evolution at a large scale.This study identifies and evaluates a set of homeotic gradients across 250 extant and fossil mammalian species and their antecedents over a period of 220 million years. These traits are generally expressed as co-linear gradients along the body axis rather than as distinct segmental identities. Relative position or occurrence sequence vary independently and are subject to polarity reversal and mirroring. Five major gradient modification sets are identified: (1)--quantitative changes of primary segmental identity pattern that appeared at the origin of the tetrapods ; (2)--frame shift relation of costal and vertebral identity which diversifies from the time of amniote origins; (3)--duplication, mirroring, splitting and diversification of the neomorphic laminar process first commencing at the dawn of mammals; (4)--emergence of homologically variable lumbar lateral processes upon commencement of the radiation of therian mammals and ; (5)--inflexions and transpositions of the relative position of the horizontal septum of the body and the neuraxis at the emergence of various orders of therian mammals. Convergent functional changes under homeotic control include laminar articular engagement with septo-neural transposition and ventrally arrayed lumbar transverse process support systems.Clusters of homeotic transformations mark the emergence point of mammals in the Triassic and the radiation of therians in the Cretaceous. A cluster of homeotic changes in the Miocene hominoid Morotopithecus that are still seen in humans supports establishment of a new "hominiform" clade and suggests a homeotic origin for the human upright body plan

    Monsters in early modern philosophy

    Get PDF
    Monsters as a category seem omnipresent in early modern natural philosophy, in what one might call a “long” early modern period stretching from the Renaissance to the late eighteenth century, when the science of teratology emerges. We no longer use this term to refer to developmental anomalies (whether a two-headed calf, an individual suffering from microcephaly or Proteus syndrome) or to “freak occurrences” like Mary Toft’s supposedly giving birth to a litter of rabbits, in Surrey in the early eighteenth-century (Todd 1995). But the term itself has a rich semantic history, coming from the Latin verb monstrare (itself deriving from monere, to remind, warn, advise), “to show,” from which we also get words like “monitor,” “admonish,” “monument” and “premonition”; hence there are proverbs like, in French, le monstre est ce qui montre, difficult to render in English: “the monsters is that which shows.” Scholars have discussed how this “monstrative” dimension of the monster is in fact twofold: on the one hand, and most awkwardly, the monster is an individual who is “pointed at,” who is shown; on the other hand, the monster is a sign, a portent, an omen, and in that sense “shows us” something (on the complex semantic history of the term across Indo-European languages see Ochsner 2005). The latter dimension persists in naturalized form in the early modern period when authors like Bacon, Fontenelle or William Hunter insist that monsters (or anomalies) can show us something of the workings of Nature
    corecore