Extinctions: Environmental controls, diversification models and the quality of the fossil record
Foster W. J., Roden V. J., Gómez Correa M. A.
This session will highlight research examining extinction events and biotic crises using the fossil record. It will cover different and competing hypotheses that investigate the role of the environment and biotic interactions during the extinction events and subsequent recoveries. In addition, it will also look at how the quality of the fossil record confounds our interpretations that these hypotheses are based on.
Circum-Mediterranean aquatic biodiversity – from deep time to the recent
Harzhauser M., Zuschin M.
The session aims for bringing together scientists who work on fossil and recent groups of aquatic organisms from the Circum-Mediterranean Region. We encourage submissions on taxonomy, (palaeo)ecology and actuopalynology. Biostratigraphic contributions and palaeogeographic considerations are welcome as well if the focus is laid on organisms. Geographically, we invite especially contributions focusing on the Tethys Ocean, the Mediterranean Sea, the Paratethys Sea, the Black Sea and the Caspian Sea, but emphasize that talks on freshwater organisms are equally welcome.
Insect diversity in the past as a basis for understanding the modern-day crisis
Haug J. T., Haug C., Solórzano-Kraemer M.
Currently, the loss of insect diversity in modern-day ecosystems is a ubiquitous relevant theme. Several studies in recent years indicated that there is a tremendous decrease of insect biomass and abundance across different modern ecosystems. The reasons that led to this decrease include, among other, pesticide usage, habitat destruction or climate change. Also in past ecosystems of different geological time periods insect diversity faced severe changes. The first insects are known from the Devonian. In the Carboniferous, the first major radiation occurred, especially of the group Palaeoptera. Among fossils from this time period, the largest representatives of flying insects have been found. During the Mesozoic, the groups Paraneoptera and Holometabola underwent further large radiations, especially also in co-evolution with the rise of flowering plants. These radiations of certain lineages often co-occurred with the extinction or heavy decline of other lineages. Studies on fossil insect diversity can provide valuable data to compare with the data we have from the present ecosystems. In this symposium, we want to look at fossil diversity, patterns at specific time slices, changes of diversity over longer periods, as well as different methods for measuring diversity.
Unravelling the complexity of continental Palaeoecosystems: interactions and interrelatedness between plants, other organisms, and environments
Kunzmann L., Rößler R., Roth-Nebelsick A., Schneider J. W., Wappler T.
Life on Earth depends on and evolved within a multitude of complex abiotic and biotic interactions always driven by the need of organisms to gain metabolic energy from resources of their environment for survival, reproduction and competition. These interactions promoted the evolution of biodiversity and complexity of ecosystems discernible in various processes such as co-evolution of organismic groups, predator-prey interactions, and complex reproduction and defense strategies. Besides, the interrelatedness between biota and environment also involves various biogeochemical cycles on different time scales.
This symposium aims for contributions for understanding fundamental interactions between plants and various other groups of organisms (e.g., fungi, insects, vertebrates) from any time interval and their interplay with a variety of environmental factors in different continental depositional systems. In particular, interactions between plants and herbivorous arthropods, known since 425 Ma, elucidate a fundament of the continental trophic network that represents at least 75% of the global macro-biodiversity in modern terrestrial ecosystems. Moreover, plants’ functional traits evolved as “optimizations” between disparate needs: to adapt to abiotic environmental conditions, to allow for mutual benefit biotic interactions, and to develop effective defensive mechanisms against any biotic attacks. The fossil record is full of examples documenting fascinating complex solutions from adaptive processes.
Microanatomy and Histology: new insights from classical light microscopy and x-ray microtomography
van Heteren A. H., Sander P. M.
Microanatomy and histology are the microscopic study of tissue structure. Bones are the primary anatomical structures comprising of the skeletal system. Bone is made up by bone tissue. There are two architectural subtypes, cortical and trabecular bone. The mineral content is chiefly hydroxyapatite crystals composed of mainly calcium and phosphate ions but can occasionally have sodium and carbonate as well. Osteocytes (bone cells) have a phylogenetically widespread distribution. Their cell processes are fundamental to allows osseous tissue to be responsive to the mechanical and metabolic organism constraints. Simple vascular canals as well as primary and secondary osteons with their central canal ensure the bone's arterial, venous, and nerve supply.
Bones adapt and remodel constantly. A good understanding of bone microanatomical and histological variation is essential for understanding how bone responds to differential biomechanical loading, which is important in the medical and veterinary sciences, but also inspires engineering solutions. The primary mechanical determinants of the strength of bone are specific for the subtype: width and porosity for cortical bone, and shape, width, connectivity, and anisotropy for trabecular bone. Due to the fact that tissue type and bone growth marks reflect tempo and rate of bone growth, bone histology is a valuable tool for reconstructions of life histories and growth patterns.
Environmental conditions and behaviour impact animal biology and cause evolutionary and individual transformations of bone microanatomy and histology. The meaning and implication of various bone tissue types, as well as their relationships to biological factors such as shape, development, biomechanical loading, body size, ecology, rate and cyclicity of growth and longevity are important factors. Studying these in modern species and comparisons with fossils allow for palaeoenvironmental and palaeoetiological inferences.
The principal directive of this symposium is to bring together users of X-ray microtomography and synchrotron radiation microtomography with experts on thin sections working on bone. We welcome contributions from all geological periods and on all vertebrate taxa.
Jurassic-Cretaceous terrrestrial biota - Evolution and Palaeoecology
Martin T., Schultz J. A.
The middle to late Mesozoic (Jurassic-Cretaceous) is a crucial period in earth history because the roots of modern environments go way back to this era. The break-up of Pangaea changed the configuration of continents and the face of the earth towards that of the modern world and triggered organismic evolution on land. During that time modern world ecosystems, organismic interactions and biomes began to form. The world´s climate changed from global greenhouse conditions to moderate and cooler temperatures in high latitudes. Terrestrial organisms were forced to develop physiological adaptations to cope with the changing environments, and the separation of northern and southern continents lead to vicariance and provincialism. Dinosaurs ruled the continents and gave rise to the first birds, and lissamphibians and mammals stood at their early beginnings. The latter showed an unexpected ecomorphological diversity and disparity representing all adaptive types known from modern marsupials and placentals, except for active flight. The key to understand today´s organisms and ecosystems, knowledge of their complex Mesozoic origins is crucial. As a rule, evolutionary innovations arise from small-bodied vertebrate generalists. In recent years the knowledge of Mesozoic microvertebrates, especially amphibians and mammals, has increased dramatically, and cutting-edge innovative techniques such as synchroton and high-resolution µCT investigations allow the analysis of structures at submillimetre scale. The symposium aims to bring together experts on Mesozoic terrestrial vertebrates in order to discuss some latest developments in the research of Mesozoic terrestrial life, especially on phylogeny, palaeobiogeography, and ecomorphology.