Early bursts of diversification defined the faunal colonization of land

The colonization of land was one of the major events in Earth history, leading to the expansion of life and laying the foundations for the modern biosphere. We examined trace fossils, the record of the activities of past life, to understand how animals diversify both behaviourally and ecologically when colonizing new habitats. The faunal invasion of land was preceded by excursions of benthic animals into very shallow, marginal marine environments during the latest Ediacaran period and culminated in widespread colonization of non-marine niches by the end of the Carboniferous period. Trace fossil evidence for the colonization of new environments shows repeated early burst patterns of maximal ichnodisparity (the degree of difference among basic trace fossil architectural designs), ecospace occupation and level of ecosystem engineering prior to maximal ichnodiversity. Similarities across different environments in the types of behavioural programme employed (as represented by different trace fossils), modes of life present and the ways in which animals impacted their environments suggest constraints on behavioural and ecological diversification. The early burst patterns have the hallmark of novelty events. The underlying drivers of these events were probably the extrinsic limitation of available ecospace and intrinsic controls of genomic and developmental plasticity that enabled trace-maker morphological and behavioural novelty.Financial support for the initial part of this project was provided to N.J.M. through a Government of Canada Post-doctoral Research Fellowship under the Canadian Commonwealth Scholarship Program. Additional funding was provided by the Natural Sciences and Engineering Research Council (NSERC) Discovery Grants 311726-05/08/15 and 311727-05/08/13 (to L.A.B. and M.G.M., respectively). M.R.G also acknowledges funding from an NSERC Discovery Grant. This is Earth Sciences Sector contribution number 20160255 and contribution 314 of the Evolution of Terrestrial Ecosystems Consortium of the National Museum of Natural History, Washington DC

High-resolution computed tomography reconstructions of invertebrate burrow systems

The architecture of biogenic structures can be highly influential in determining species contributions to major soil and sediment processes, but detailed 3-D characterisations are rare and descriptors of form and complexity are lacking. Here we provide replicate high-resolution micro-focus computed tomography (μ-CT) data for the complete burrow systems of three co-occurring, but functionally contrasting, sediment-dwelling inter-tidal invertebrates assembled alone, and in combination, in representative model aquaria. These data (≤2,000 raw image slices aquarium−1, isotropic voxel resolution, 81 μm) provide reference models that can be used for the development of novel structural analysis routines that will be of value within the fields of ecology, pedology, geomorphology, palaeobiology, ichnology and mechanical engineering. We also envisage opportunity for those investigating transport networks, vascular systems, plant rooting systems, neuron connectivity patterns, or those developing image analysis or statistics related to pattern or shape recognition. The dataset will allow investigators to develop or test novel methodology and ideas without the need to generate a complete three-dimensional computation of exemplar architecture

Evolution in Caffeoylquinic Acid Content and Histolocalization During Coffea canephora Leaf Development

• Background and Aims Caffeoylquinic acids are cinnamate conjugates derived from the phenylpropanoid pathway. They are generally involved in plant responses to biotic and abiotic stress and one of them, chlorogenic acid (5-O-caffeoylquinic acid, 5-CQA), is an intermediate in the lignin biosynthesis pathway. Caffeoylquinic acids, and particularly 5-CQA, are accumulated in coffee beans, where they can form vacuolar complexes with caffeine. Coffea canephora beans are known to have high caffeoylquinic acid content, but little is known about the content and diversity of these compounds in other plant parts. To gain new insights into the caffeoylquinic acid metabolism of C. canephora, caffeoylquinic acid content and in situ localization were assessed in leaves at different growth stages

Impact of Permian mass extinctions on continental invertebrate infauna

The Capitanian (late middle Permian) and end‐Permian mass extinctions were particularly severe from a palaeoecological perspective. Previous studies of their expressions on land underscored their impacts on plants and vertebrates, but the effects on the continental invertebrate infauna remain poorly understood. A multiproxy analysis from the Iberian Basin (Central Spain) reveals a dramatic decrease in bioturbation intensity on land by the end of the Capitanian. This pattern cannot be explained by facies effects because our analysis is based on similar types of deposits through the succession and over an extensive area. The bioturbation crisis coincided with an increase in weathering intensity and acidic conditions, and a collapse in plant communities spanning the late Permian–Early Triassic in the Iberian Basin. Reduced bioturbation may have contributed to decrease in mechanical reworking of the sediment and soil, affected geochemical recycling, increased sediment acidification and impacted on ecosystem structure. Identification of this infaunal crisis on land underscores the ecological severity of mass extinctions and emphasises the significance of feedback loops in riparian ecosystems

Early Permian during the Variscan orogen collapse in the equatorial realm: insights from the Cantabrian Mountains (N Iberia) into climatic and environmental changes

We report the results of a multidisciplinary study of the early Permian (Artinskian–Kungurian) Sotres Formation of northern Spain integrating sedimentology, palaeosols, mineralogy, stable isotopes, palynology, ichnology and tectonics. This continental unit was deposited in the near-equatorial Peri-Tethyan Cantabrian Basin. Having developed in the middle of the Variscan fold belt, it is preserved within the present-day Cantabrian Mountains. Three subunits are recognised in the Sotres Formation based on tectono-stratigraphic and sedimentological data: a lower alluvial subunit, a middle carbonate lacustrine subunit, and an upper palustrine subunit. Multidisciplinary results reveal an upward change in climate from humid-subhumid conditions at the base of the formation (Artinskian) to semi-arid and arid conditions at the top of the formation (Kungurian), which may reflect global deglaciation near the end of the Late Paleozoic Ice Age and a probable northward migration of the Intertropical Convergence Zone. This general upward warming/drying climate trend was interrupted by a short-lived interval of monsoon conditions in mid-Kungurian times, which may have coincided with a pulse of global cooling. Our findings are in agreement with the climate trends reported for other central Pangaean basins. Rising CO2 levels may have been a driving factor for climate transition during this time interval. However, in our study area, which lies within the active central Variscan orogenic belt, tectonic conditions must have also played a role in driving climate change