Search

Longevity and other life history variables are key to understanding evolutionary processes and the biology of extinct animals. For the past 20 years, the lifespan of cave bears received an increased interest. Studies focusing on incremental lines of tooth cementum resulted in detailed mortality patterns from different localities. In this review, we summarise literature on age estimation as well as mortality of different European cave bear localities and present novel data on longevity from 94 teeth originating from 20 European localities. Additionally, the relative tooth emergence pattern of the permanent dentition is investigated under the Schultz’s rule framework of possible life history implications. For this, the known sequences of extant bear species are compared with the one of cave bears. Our results suggest that the typical duration of the life of cave bears was 19 years but data from literature show that in rare cases ages of up to 30–32 years were achieved. Additionally, we present the oldest known age for the Middle Pleistocene cave bear Ursus deningeri, 29 years. The tooth eruption pattern of cave bears exhibits a heterochronic shift that implies, under the assumption of Schulz’ rule, a slightly faster life history than closely related species.

Mollusks such as ammonoids record their growth in their accretionary shells making them ideal to study evolutionary changes in ontogeny through time. Standard methods usually focus on two dimensional data and do not quantify empirical changes in shell and chamber volumes through ontogeny which can be of importance to disentangle phylogeny interspecific variation and paleobiology of these now extinct cephalopods. Tomographic and computational methods now offer the opportunity to empirically study volumetric changes in shell and chamber volumes through ontogeny of major ammonoid subclades. Here we document (1) the growth of chamber and septal volumes through ontogeny and (2) differences in ontogenetic changes between one species each of three major subclades of Paleozoic ammonoids throughout their early phylogeny. The data used in this study are 3D reconstructions of specimens subjected to grinding tomography. The following species have been studied: the Middle Devonian agoniatitid Fidelites clariondi the Middle Devonian anarcestid Diallagites lenticulifer and the Early Carboniferous goniatitid Goniatites multiliratus. Chamber and septum volumes were plotted versus the septum number and the shell diameter (proxies for growth) in the three species; differences are rather small but the trajectories are more similar among the most derived Diallagites and Goniatites compared with the more loosely coiled Fidelites. Our comparisons show a good correlation between the 3D and the 2D measurements. In all three species both volumes follow exponential trends with deviations in very early ontogeny (artifacts by lack of resolution) and near maturity (mature modifications in shell growth).

Molluscs such as ammonoids record their growth in their accretionary shells making them ideal for the study of evolutionary changes in ontogeny through time. Standard methods usually focus on two dimensional data and do not quantify empirical changes in shell and chamber volumes through ontogeny which can possibly be important to disentangle phylogeny interspecific variation and palaeobiology of these extinct cephalopods. Tomographic and computational methods offer the opportunity to empirically study volumetric changes in shell and chamber volumes through ontogeny of major ammonoid sub clades in three dimensions (3 D). Here we document (1) the growth of chamber and septal volumes through ontogeny and (2) differences in ontogenetic changes between species from each of three major sub clades of Palaeozoic ammonoids throughout their early phylogeny. The data used are three dimensional reconstructions of specimens that have been subjected to grinding tomography. The following species were studied: the agoniatitid Fidelites clariondi and anarcestid Diallagites lenticulifer (Middle Devonian) and the Early Carboniferous goniatitid Goniatites multiliratus. Chamber and septum volumes were plotted against the septum number and the shell diameter (proxies for growth) in the three species; although differences are small the trajectories are more similar among the most derived Diallagites and Goniatites compared with the more widely umbilicate Fidelites. Our comparisons show a good correlation between the 3 D and the 2 D measurements. In all three species both volumes follow exponential trends with deviations in very early ontogeny (resolution artefacts) and near maturity (mature modifications in shell growth). Additionally we analyse the intraspecific differences in the volume data between two specimens of Normannites (Middle Jurassic).

von Chr. Kolb In Fraktur Enth. außerdem: Scholicus ordo des Mag. Bartholomäus Stich für die Haller Lateinschule (ungefähr 1514) Progr.-Nr. 556

The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallelfibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. fromthe LateOligocene of Turkey is represented by denseHaversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of Japan closely related to Megaloceros, indicate a high growth rate. These examples and the synthesis of existing data show the potential of bone microstructure to reveal essential information on life history evolution. The bone tissue and the skeletochronological data of the sampled island species suggest the presence of various modes of bone histological modification and mammalian life history evolution on islands to depend on factors of island evolution such as island size, distance frommainland, climate, phylogeny, and time of evolution. Fil: Kolb, Christian. Universitat Zurich; Suiza Fil: Scheyer, Torsten M.. Universitat Zurich; Suiza Fil: Veitschegger, Kristof. Universitat Zurich; Suiza Fil: Forasiepi, Analia Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Amson, Eli. Universitat Zurich; Suiza Fil: Van der Geer, A.. Naturalis Biodiversity Center; Países Bajos. University of Athens; Grecia Fil: Van den Hoek Ostende, Lars. Naturalis Biodiversity Center; Países Bajos Fil: Hayashi, Shoi. Osaka Museum of Natural History; Japón Fil: Sanchez Villagra Marcelo R.. Universitat Zurich; Suiza

Background Body size variation within clades of mammals is widespread, but the developmental and life-history mechanisms by which this variation is achieved are poorly understood, especially in extinct forms. An illustrative case study is that of the dwarfed morphotypes of Candiacervus from the Pleistocene of Crete versus the giant deer Megaloceros giganteus, both in a clade together with Dama dama among extant species. Histological analyses of long bones and teeth in a phylogenetic context have been shown to provide reliable estimates of growth and life history patterns in extant and extinct mammals. Results Similarity of bone tissue types across the eight species examined indicates a comparable mode of growth in deer, with long bones mainly possessing primary plexiform fibrolamellar bone. Low absolute growth rates characterize dwarf Candiacervus sp. II and C. ropalophorus compared to Megaloceros giganteus displaying high rates, whereas Dama dama is characterized by intermediate to low growth rates. The lowest recorded rates are those of the Miocene small stem cervid Procervulus praelucidus. Skeletal maturity estimates indicate late attainment in sampled Candiacervus and Procervulus praelucidus. Tooth cementum analysis of first molars of two senile Megaloceros giganteus specimens revealed ages of 16 and 19 years whereas two old dwarf Candiacervus specimens gave ages of 12 and 18 years. Conclusions There is a rich histological record of growth across deer species recorded in long bones and teeth, which can be used to understand ontogenetic patterns within species and phylogenetic ones across species. Growth rates sensu Sander & Tückmantel plotted against the anteroposterior bone diameter as a proxy for body mass indicate three groups: one with high growth rates including Megaloceros, Cervus, Alces, and Dama; an intermediate group with Capreolus and Muntiacus; and a group showing low growth rates, including dwarf Candiacervus and Procervulus. Dwarf Candiacervus, in an allometric context, show an extended lifespan compared to other deer of similar body size such as Mazama which has a maximum longevity of 12 years in the wild. Comparison with other clades of mammals reveals that changes in size and life history in evolution have occurred in parallel, with various modes of skeletal tissue modification. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0295-3) contains supplementary material, which is available to authorized users.