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Two thin-toed tridactyl tracks in a fluvial sandstone bed of the Eumeralla Formation (Albian) at Dinosaur Cove (Victoria, Australia) were likely made by avian trackmakers, making these the oldest known fossil bird tracks in Australia and the only Early Cretaceous ones from Gondwana. These tracks, which co-occur on the same surface with a slightly larger nonavian theropod track, are distinguishable by their anisodactyl form, hallux impressions and wide digit II–IV divarication angles.

• Read more about Oldest known avian footprints from Australia: Eumeralla Formation (Albian), Dinosaur Cove, Victoria

This, the second in the series of virtual issues of Palaeontology, charts the development of concepts in ammonoid palaeobiology, with reference to nine selected papers published in this journal from 1965 onwards. These cover a broad range of topics: goniatite bed palaeoecology, systematics and evolution in Scaphites, flow dynamics of cephalopod shells, shell growth and differential geometry, septal function, ammonoid assemblage analysis, evolutionary trends, stratocladistics, and soft part preservation.

• Read more about Ammonoid palaeobiology

Large-scale evolution involves several layers of complexity spanning multiple scales, from genes and organisms to whole ecosystems. In this article, we review several models involving the macroevolution of artificial organisms, communities or ecosystems, highlighting their importance and potential role in expanding the Modern Synthesis. Afterwards, we summarize the key results obtained from our model of artificially evolved ecosystems where individuals are defined as embodied entities within a physical, simulated world where they can evolve different traits and exploit multiple resources.

• Read more about Macroevolution in silico: scales, constraints and universals

Darwin's On the Origin of Species has led to a theory of evolution with a mass of empirical detail on population genetics below species level, together with heated debate on the details of macroevolutionary patterns above species level. Most of the main principles are clear and generally accepted, notably that life originated once and has evolved over time by descent with modification. Here, I review the fossil and molecular phylogenetic records of the response of life on Earth to Quaternary climatic changes.

• Read more about Is the number of species on earth increasing or decreasing? Time, chaos and the origin of species

There may be structural principles pertaining to the general behaviour of systems that lead to similarities in a variety of different contexts. Classic examples include the descriptive power of fractals, the importance of surface area to volume constraints, the universality of entropy in systems, and mathematical rules of growth and form. Documenting such overarching principles may represent a rejoinder to the Neodarwinian synthesis that emphasizes adaptation and competition. Instead, these principles could indicate the importance of constraint and structure on form and evolution.

• Read more about Declining volatility, a general property of disparate systems: from fossils, to stocks, to the stars

Modern studies of individual populations have shown large cyclical shifts in phenotype/genotype that correlate with climatic variations. At the hierarchical level of the species, similar patterns can be observed in the climatically mediated turnover of species (i.e. Vrba's Relay Model). In turn, mass extinction events may have a similar analogous relationship with species turnover, while operating at the clade level. In this paper, such an analogous process is described and named ‘the Cladal Turnover Model’.

• Read more about Cladal Turnover: the end-Ordovician as a large-scale analogue of species turnover

Evolution is seen as a future-blind process driven by ecology. At geological time scales (macroevolution), complex ecosystems (including parasites) have caused periods of relative stasis, while evolutionary change may be fostered by two kinds of exceptional situation: (1) after an extinction event, the availability of open niches gave innovative groups the chance to gain ecologic power; (2) a climatically controlled Golden Age before the event allowed Darwinian optimization to exceed the constructional limits of established bauplans.

• Read more about Patterns of macroevolution through the Phanerozoic

In trilobites as in many others extinct organisms, our understanding of the mechanisms of evolution is based on morphological and ontogenetic features. Data from ontogenetic development are essential to provide an insight into the origins of evolutionary changes. In phacopid trilobites, detailed studies of ontogenetic series have been achieved using quantitative methods.

• Read more about Morphological disparity and developmental patterning: contribution of phacopid trilobites

Evolutionary radiations have been extensively studied especially in the fossil record and in the context of postcrisis recoveries. The concept of adaptive radiation that emerges from this very broad topic explicitly involves the effect of adaptation driven by ecological opportunity and is considered to be of the foremost importance. It is essential to be able to detect adaptive radiation because it points up factors that predispose a clade to radiate.

• Read more about Adaptive radiation in the fossil record: a case study among Jurassic ammonoids

A major challenge facing conservation biology today is predicting how often species will be able to adapt to environmental change. We need to know which, and under what environmental conditions, ecologically important traits are likely to evolve and keep species in the evolutionary game. Conservation biologists currently lack enough data across a broad range of traits and taxa to address this problem, which impedes the development of scenarios of possible adaptive management responses.

• Read more about The great opportunity to view stasis with an ecological lens