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New mammal species have always been a source of major zoological intrigue, and whilst discoveries of large mammals are becoming less frequent, species like the saola and dingiso continue to enter the zoological literature. Modern communities are often assumed to be complete and are used for constructing community-level models. One example is ecometric modelling. Here, we estimate the number of large herbivorous mammals not yet described based on description curves. We also investigate the effect of species description on the stability and accuracy of previously established relationships between traits and climate. The contemporary description record of large herbivorous mammals is incomplete, with at least 83 species undescribed. Primates, artiodactyls and marsupials are estimated to contain the greatest undescribed diversity, with particular gaps in the Neotropic, Afrotropic and Indomalayan realms. We find that beyond ~40% completeness, there is a limited impact on trait–environment relationships of increased species description, but that there is a high mismatch between true and predicted climatic values for published models. Consequently, mammalian species that have not yet been discovered are unlikely to have a large impact on the accuracy of trait-environment models, but we suggest possible alterations to previous approaches that might improve the accuracy of future models. [ABSTRACT FROM AUTHOR]

A species factory refers to the source that gives rise to an exceptionally large number of species. However, what is it exactly: a place, a time or a combination of places, times and environmental conditions, remains unclear. Here we search for species factories computationally, for which we develop statistical approaches to detect origination, extinction and sorting hotspots in space and time in the fossil record. Using data on European Late Cenozoic mammals, we analyse where, how and how often species factories occur, and how they potentially relate to the dynamics of environmental conditions. We find that in the Early Miocene origination hotspots tend to be located in areas with relatively low estimated net primary productivity. Our pilot study shows that species first occurring in origination hotspots tend to have a longer average longevity and a larger geographical range than other species, thus emphasizing the evolutionary importance of the species factories. [ABSTRACT FROM AUTHOR]

A new study by Fraser et al (2018) urges the use of phylogenetic comparative methods, whenever possible, in analyses of mammalian tooth wear. We are concerned about this for two reasons. First, this recommendation may mislead the research community into thinking that phylogenetic signal is an artifact of some sort rather than a fundamental outcome of the evolutionary process. Secondly, this recommendation may set a precedent for editors and reviewers to enforce phylogenetic adjustment where it may unnecessarily weaken or even directionally alter the results, shifting the emphasis of analysis from common patterns manifested by large clades to rare cases. [ABSTRACT FROM AUTHOR]

How food intake and mastication scale to satisfy the metabolic needs of mammals has been the subject of considerable scientific debate. Existing theory suggests that the negative allometric scaling of metabolic rate with body mass is compensated by a matching allometric scaling of the chewing rate. Why empirical studies have found that the scaling coefficients of the chewing rate seem to be systematically smaller than expected from theory remains unknown. Here we explain this imparity by decoupling the functional surface area of teeth from overall surface area. The functional surface area is relatively reduced in forms emphasizing linear edges (e.g., lophodont) compared with forms lacking linear structures (e.g., bunodont). In forms with reduced relative functional surface, the deficit in food processed per chew appears to be compensated for by increased chewing rate, such that the metabolic requirements are met. This compensation accounts for the apparent difference between theoretically predicted and observed scaling of chewing rates. We suggest that this reflects adaptive functional evolution to plant foods with different fracture properties and extend the theory to incorporate differences in functional morphology. [ABSTRACT FROM AUTHOR]

Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of eastern Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago (Ma). We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change, and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 Ma have acted as a 'species factory', generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS Member (1.87-1.53 Ma), may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans. This article is part of the themed issue 'Major transitions in human evolution'. [ABSTRACT FROM AUTHOR]

The path of species diversification is commonly observed by inspecting the fossil record. Yet, how species diversity changes at geological timescales relate to lower-level processes remains poorly understood. Here we use mathematical models of spatially structured populations to show that natural selection and gradual environmental change give rise to discontinuous phenotype changes that can be connected to speciation and extinction at the macroevolutionary level. In our model, new phenotypes arise in the middle of the environmental gradient, while newly appearing environments are filled by existing phenotypes shifting their adaptive optima. Slow environmental change leads to loss of phenotypes in the middle of the extant environmental range, whereas fast change causes extinction at one extreme of the environmental range. We compared our model predictions against a well-known yet partially unexplained pattern of intense hoofed mammal diversification associated with grassland expansion during the Late Miocene. We additionally used the model outcomes to cast new insight into Cope's law of the unspecialized. Our general finding is that the rate of environmental change determines where generation and loss of diversity occur in the phenotypic and physical spaces. [ABSTRACT FROM AUTHOR]

The standard adaptive dynamics framework assumes two timescales, i.e. fast population dynamics and slow evolutionary dynamics. We further assume a third timescale, which is even slower than the evolutionary timescale. We call this the geological timescale and we assume that slow climatic change occurs within this timescale. We study the evolution of our model population over this very slow geological timescale with bifurcation plots of the standard adaptive dynamics framework. The bifurcation parameter being varied describes the abiotic environment that changes over the geological timescale. We construct evolutionary trees over the geological timescale and observe both gradual phenotypic evolution and punctuated branching events. We concur with the established notion that branching of a monomorphic population on an environmental gradient only happens when the gradient is not too shallow and not too steep. However, we show that evolution within the habitat can produce polymorphic populations that inhabit steep gradients. What is necessary is that the environmental gradient at some point in time is such that the initial branching of the monomorphic population can occur. We also find that phenotypes adapted to environments in the middle of the existing environmental range are more likely to branch than phenotypes adapted to extreme environments. [ABSTRACT FROM AUTHOR]

Both pliopithecoid and hominoid primates were widely distributed throughout Eurasia during the Miocene but are known to have coexisted at only a few localities. It has been speculated that their different habitat preferences permitted only minimal overlap under special environmental conditions. Here we study the context for pliopithecoid and hominoid co-occurrence by assessing taxonomically-based palaeoecological diversity of associated fossil mammals and by direct ecometric analysis based on hypsodonty of mammalian herbivores. Our results show that pliopithecoids persistently inhabited more humid environments compared to the other primate groups studied, suggesting an inability to adapt to changing environmental conditions. The opportunity for hominoids and pliopithecoids to co-occur appears to have been restricted by niche conservatism in the latter group. Our study also indicates that direct ecometric analysis gives a better separation of the ecological preferences of these primate clades than do analyses of taxonomically-based community structure. [ABSTRACT FROM AUTHOR]

The relative weights of physical forcing and biotic interaction as drivers of evolutionary change have been debated in evolutionary theory. The recent finding that species, genera, clades, and chronofaunas all appear to exhibit a symmetrical pattern of waxing and waning lends support to the view that biotic interactions shape the history of life. Yet, there is similarly abundant evidence that these primary units of biological evolution arise and wane in coincidence with major climatic change. We review these patterns and the process-level explanations offered for them. We also propose a tentative synthesis, characterized by interdependence between physical forcing and biotic interactions. We suggest that species with evolutionary novelties arise predominantly in 'species factories' that develop under harsh environmental conditions, under dominant physical forcing, whereas exceptionally mild environments give rise to 'oases in the desert,' characterized by strong competition and survival of relics. [ABSTRACT FROM AUTHOR]

An ever larger proportion of Earth's biota is affected by the current accelerating environmental change. The mismatches between organisms and their environments are now increasing in both magnitude and frequency, resulting in lowered fitness and hence the decline of populations. Under this scenario, species with behavioral and/or physiological traits that provide them shelter from the environment are predicted to be less vulnerable to population declines than species that are always exposed to the elements. Here, we coded 4,536 living mammal species for sleep-or-hide (SLOH) behavior, including hibernation, torpor, and the use of burrows, among other related traits. We demonstrate that species that exhibit SLOH behavior are underrepresented in high-risk International Union for Conservation of Nature Red List categories. We found that SLOH behavior contributes to lowering extinction risk even after we accounted for other factors that directly or indirectly buffer species against extinction, such as larger geographic ranges and smaller body sizes. This result is robust to analyses using phylogenetically independent contrasts. Sleep-or-hide behavior, made possible by a related suite of physiological adaptations, allows mammals to function at lower metabolic rates and/or buffer them from changing physical elements. Mammals with SLOH behavior have a greater propensity to survive in the current extinction crisis and probably also in past crises because of reduced exposure to environmental stress. [ABSTRACT FROM AUTHOR]

Do large mammals evolve faster than small mammals or vice versa? Because the answer to this question contributes to our understanding of how life-history affects long-term and large-scale evolutionary patterns, and how microevolutionary rates scale-up to macroevolutionary rates, it has received much attention. A satisfactory or consistent answer to this question is lacking, however. Here, we take a fresh look at this problem using a large fossil dataset of mammals from the Neogene of the Old World (NOW). Controlling for sampling biases, calculating per capita origination and extinction rates of boundary-crossers and estimating survival probabilities using capture-mark-recapture (CMR) methods, we found the recurring pattern that large mammal genera and species have higher origination and extinction rates, and therefore shorter durations. This pattern is surprising in the light of molecular studies, which show that smaller animals, with their shorter generation times and higher metabolic rates, have greater absolute rates of evolution. However, higher molecular rates do not necessarily translate to higher taxon rates because both the biotic and physical environments interact with phenotypic variation, in part fueled by mutations, to affect origination and extinction rates. To explain the observed pattern, we propose that the ability to evolve and maintain behavior such as hibernation, torpor and burrowing, collectively termed "sleep-or- hide" (SLOH) behavior, serves as a means of environmental buffering during expected and unexpected environmental change. SLOH behavior is more common in some small mammals, and, as a result, SLOH small mammals contribute to higher average survivorship and lower origination probabilities among small mammals. [ABSTRACT FROM AUTHOR]

Background: Specialised leaf-eating is almost universally regarded as the ancestral state of all ruminants, yet little evidence can be cited in support of this assumption, apart from the fact that all early ruminants had low crowned cheek teeth. Instead, recent years have seen the emergence evidence contradicting the conventional view that low tooth crowns always indicate leaf-eating and high tooth crowns grass-eating. Results: Here we report the results of two independent palaeodietary reconstructions for one of the earliest deer, Procervulus ginsburgi from the Early Miocene of Spain, suggesting that despite having lower tooth crowns than any living ruminant, this species included a significant proportion of grass in its diet. Conclusion: The phylogenetic distribution of feeding styles strongly supports that leaf-grass mixed feeding was the original feeding style of deer, and that later dietary specialization on leaves or grass occurred independently in several lineages. Evidence for other ruminant clades suggests that facultative mixed feeding may in fact have been the primitive dietary state of the Ruminantia, which would have been morphologically expressed only under specific environmental factors. [ABSTRACT FROM AUTHOR]

Abstract: The fossil teeth of land mammals offer a powerful tool to map the regional details of past climate change in the terrestrial realm. We use mean plant-eater hypsodonty (molar crown height) of late Neogene mammal localities to map late Miocene and Pliocene palaeoprecipitation on the Eurasian continent and, with higher temporal resolution, in Europe. The results show that the mid-latitude drying in Eurasia affected the central parts of the continent first and that the drying of western Europe after about 7–8 Ma seems to have coincided roughly in time with a return to more humid conditions in eastern Asia, with a return to a drier east and more humid west in the Pliocene. Within Europe, the hypsodonty-based palaeoprecipitation maps suggest that the sequence from MN 9 to MN 12 (ca. 11.1–6.8 Ma) was dominated by an east–west (continental-marine) humidity gradient, which gradually intensified and with a shift of dryer conditions eastwards in MN 12 (ca. 7.5 Ma). This was partly overlain from MN 13 onwards by a north–south oriented gradient, which persisted at least to the end of the Pliocene. The maps for both the earliest late Miocene (MN 9, ca. 11.1–9.7 Ma) and the earliest Pliocene (MN 14, ca. 4.9–4.2 Ma) show very low regional differentiation, possibly suggesting perturbed phases in the evolution of the mammal communities. Analysis of hypsodonty and dietary structure of the mammalian plant-eater community in Europe during the entire interval shows that the Miocene–Pliocene boundary was marked by a strong decrease in mesodont species and mixed feeders, and an increase in brachydont species and omnivores. In this view, the shift in the latest Miocene from east–west to partly north–south-polarised hypsodonty patterns corresponds mainly to an increase in hypsodont species and grazers. It seems probable that the east–west gradient was primarily driven by precipitation, while the north–south gradient would also have been strongly influenced by temperature-related effects of humidity. [Copyright &y& Elsevier]

Given a collection of fossil sites with data about the taxa that occur in each site, the task in biochronology is to find good estimates for the ages or ordering of sites. We describe a full probabilistic model for fossil data. The parameters of the model are natural: the ordering of the sites, the origination and extinction times for each taxon, and the probabilities of different types of errors. We show that the posterior distributions of these parameters can be estimated reliably by using Markov chain Monte Carlo techniques. The posterior distributions of the model parameters can be used to answer many different questions about the data, including seriation (finding the best ordering of the sites) and outlier detection. We demonstrate the usefulness of the model and estimation method on synthetic data and on real data on large late Cenozoic mammals. As an example, for the sites with large number of occurrences of common genera, our methods give orderings, whose correlation with geochronologic ages is 0.95. [ABSTRACT FROM AUTHOR]

Commonness of organisms typically fluctuates through time, and understanding such fluctuations has long been an important part of ecological research. Studies at paleontological timescales provide a perspective on how changes in population size might affect community structure over millions of years. To overcome the obstacle that population size parameters such as abundance are difficult to detect in the fossil record, we here used fossil locality coverage to approximate changes in site occupancy in the Neogene of Europe over the course of 20 million years. Our aim was to examine whether the trophic structure of mammalian communities is maintained through time despite continuing environmental change. Ecomorphological grouping of fossils indicates that herbivore genera have low taxon resilience in that each genus has predominantly only one locality coverage peak before disappearance. Despite this continuous replacement of the most prevalent herbivore genera, the herbivore trophic group as a whole remains the largest and maintains a roughly constant share of locality coverage throughout the Neogene. The successive herbivore genera, however, show increasing adaptations to harshening environments, indicating shifting properties of niches while the overall trophic structure is conserved. Carnivores, dependent on primary productivity for food indirectly through their prey, show moderate lack of resilience. In contrast, in omnivores changes in locality coverage are close to random fluctuations. [ABSTRACT FROM AUTHOR]

Investigates the influence of herbivorous mammals in the evolution of hypsodonty in Europe. Detection of low hypsodonty in Miocene epoch; Examination of palaeoecological changes in the species; Effects of environmental change on biota.

The author discusses the evolution of humans in Africa. He explains that the humans evolved in Africa because of the abundance of availability of meat in the form of medium-sized hoofed mammals. He discusses a study by researcher Norman Owen-Smith published in the journal to elucidate the reasons behind the evolution of humans in Africa.

Most suids (Mammalia: Suidae, pigs) worldwide are omnivores living in closed environments, but the African warthog ( Phacochoerus ) has special adaptations for grazing in open environments. Similar specializations have been recorded from Plio-Pleistocene African suids. Four genera, Nyanzachoerus , Notochoerus , Kolpochoerus, and Metridiochoerus, have been discovered in late Miocene to middle Pleistocene locations around the Turkana Basin. We analyse the relative abundances of these four suid genera compared to other mammals, from approximately 8–0.7 Ma. The dataset includes most of the mammal specimens collected from locations around the Kenyan side of the Turkana Basin. Species of genus Nyanzachoerus were dominant before 4 Ma, but their relative abundance decreases through time thereafter. At the same time, Notochoerus increases in relative abundance, followed by Kolpochoerus, and finally Metridiochoerus . Their peak relative abundances do not overlap: Notochoerus peaks at 3.44–2.53 Ma, Kolpochoerus at 2.53–1.87 Ma, and Metridiochoerus at 1.38–0.7 Ma. We interpret the palaeoecology of these suids based on their relative abundances over time and on published isotope and pollen data. We find that Nyanzachoerus was replaced by its abrasive-diet-specialized successor Notochoerus , possibly in response to a rapid decrease in forest cover. Notochoerus adapted at first to the expanding wood- and grasslands, and then to more arid shrublands. After a period of severe aridity around 2.7–2.5 Ma, more variable environments allowed Kolpochoerus and Metridiochoerus to disperse, while Notochoerus disappeared, perhaps having lost its competitive edge. Further changes in the environment encouraged the expansion of grasslands over shrublands, favouring Metridiochoerus . Kolpochoerus persisted in the more closed environments near water sources. [ABSTRACT FROM AUTHOR]

The evolution of high-crowned teeth or hypsodonty in herbivorous mammals is widely interpreted as a species-specific adaptation to increasingly wear-inducing diets and environments at evolutionary time scales, with internal abrasives (such as phytoliths in grasses) and/or external abrasives (such as dust or grit) as putative causative factors. The mesowear score ( MS) instead describes tooth wear experienced by individual animals during their lifetime., Under the assumption that the abrasiveness that causes the MS in individuals is the same abrasiveness to which species adapted by evolving hypsodonty, one would expect a close correlation between the MS and the hypsodonty index ( HI). Alternatively, if these two measures reflect different aspects of wear, one would expect differences in the way that proxies of diet or environment/climate correlate with each parameter., In order to test these hypotheses, we collated a dataset on the HI, MS, percentage of grass in the natural diet (%grass), habitat (open, intermediate, closed) and annual precipitation ( PREC) in extant mammalian herbivores. The availability of a quantitative MS constrained the dataset to 75 species. Data were analysed with and without phylogenetic generalized least squares., Correlations with PREC were stronger for HI than for MS, whereas correlations with %grass were similar for HI and MS. Habitat had a significant influence on the relationship with %grass for HI but not for MS. Habitat also had a significant influence on the relationship between HI and MS. MS improved the predictive power of HI for %grass, but not for PREC., These results suggest that while the MS indicates predominantly the wear effect of the diet (internal abrasives), HI represents an adaptation to a wear effect that comprises both diet and environment (external abrasives). The additional environmental wear effect must reduce tooth height without causing macroscopic changes in tooth facet development as described by the MS., The most parsimonious explanation for the apparent discrepancy between HI and MS is that external abrasives of very fine particle size play a major role in naturally occurring tooth wear. The experimental testing of this hypothesis will enhance our understanding of the processes involved in tooth wear. [ABSTRACT FROM AUTHOR]

Ice Age megafauna have long been known to be associated with global cooling during the Pleistocene, and their adaptations to cold environments, such as large body size, long hair, and snow-sweeping structures, are best exemplified by the woolly mammoths and woolly rhinos. These traits were assumed to have evolved as a response to the ice sheet expansion. We report a new Pliocene mammal assemblage from a high-altitude basin in the western Himalayas, including a primitive woolly rhino. These new Tibetan fossils suggest that some megaherbivores first evolved in Tibet before the beginning of the Ice Age. The cold winters in high Tibet served as a habituation ground for the megaherbivores, which became preadapted for the Ice Age, successfully expanding to the Eurasian mammoth steppe. [ABSTRACT FROM AUTHOR]

One of the classic examples of faunal turnover in the fossil record is the Miocene transition from faunas dominated by anchitheriine horses with low-crowned molar teeth to faunas with hipparionine horses characterized by high-crowned teeth. The spread of hipparionine horses is associated with increased seasonality and the expansion of open habitats. It is generally accepted that anchitheriine horses did not display an evolutionary increase in tooth crown height prior to their extinction. Nevertheless, to test whether anchitheriines showed any changes interpretable as adaptation to local conditions, we analyzed molar teeth from multiple populations of Anchitherium in three dimensions. Our results show differences in tooth morphology that suggest incipient hypsodonty in Spain, the first region experiencing increasingly arid conditions in the early Miocene of Europe. Furthermore, analyses of tooth wear show that Spanish specimens cluster with present ungulates that eat foliage together with grasses and shrubs, whereas German specimens cluster with present-day ungulates that eat mostly foliage. Taken together, even a taxon such as Anchitherium, with a long and successful history of forest adaptation, did respond to regional environmental changes in an adaptive manner. [ABSTRACT FROM AUTHOR]

Abstract: The East Asian climate history during the Neogene is a complicated and contentious issue, in particular because of its bearing on the development of the East Asian monsoon and Tibetan uplift chronology. Here we present a paleoprecipitation analysis based on mean molar tooth height (hypsodonty) of large herbivorous mammals to investigate the spatial pattern of climate zonation in East Asia during the middle Miocene. We show a generally humid and uniform situation before the late middle Miocene, replaced by a mid-latitude arid belt from the late middle Miocene, into the earlier part of the late Miocene. These findings are concordant with the global phenomena of the middle Miocene climate optimum and the subsequent cooling, and suggest that the predominant climate in East Asia for most of the Miocene was planetary rather than monsoonal. Our results support a late initiation of the East Asian summer monsoon, coincidentally with the beginning of eolian red clay deposition in the later late Miocene at 7–8 Ma. [Copyright &y& Elsevier]

The study of mammalian evolution depends greatly on understanding the evolution of teeth and the relationship of tooth shape to diet. Links between gross tooth shape, function and diet have been proposed since antiquity, stretching from Aristotle to Cuvier, Owen and Osborn. So far, however, the possibilities for exhaustive, quantitative comparisons between greatly different tooth shapes have been limited. Cat teeth and mouse teeth, for example, are fundamentally distinct in shape and structure as a result of independent evolutionary change over tens of millions of years. There is difficulty in establishing homology between their tooth components or in summarizing their tooth shapes, yet both carnivorans and rodents possess a comparable spectrum of dietary specializations from animals to plants. Here we introduce homology-free techniques to measure the phenotypic complexity of the three-dimensional shape of tooth crowns. In our geographic information systems (GIS) analysis of 441 teeth from 81 species of carnivorans and rodents, we show that the surface complexity of tooth crowns directly reflects the foods they consume. Moreover, the absolute values of dental complexity for individual dietary classes correspond between carnivorans and rodents, illustrating a high-level similarity between overall tooth shapes despite a lack of low-level similarity of specific tooth components. These results suggest that scale-independent forces have determined the high-level dental shape in lineages that are widely divergent in size, ecology and life history. This link between diet and phenotype will be useful for inferring the ecology of extinct species and illustrates the potential of fast-throughput, high-level analysis of the phenotype. [ABSTRACT FROM AUTHOR]

Several large suid cranial remains attributed to Microstonyx major are part of a new Hipparion Fauna collection from the Hezheng area, Northern China. The new material confirms the presence of Microstonyx in the late Miocene of the area. The Chinese form belongs to a small-sized eastern population with reduced premolar row and clear sexual bimodality. Statistical comparison shows that Microstonyx major was a polymorphic species and reinforces recognition of Hippopotamodon as a separate genus, defined by relatively stout premolars resulting from a different underlying pattern of allometric growth. The presence of Microstonyx in North China and the distinct suid assemblage that lived there suggest biogeographic connections between Northern China and Western Eurasia in contrast to isolation from Southern China and the Indian subcontinent. The suid fauna of the late Miocene of Northern China seems to have been restricted to the later, more humid phase represented by the Red Clay faunas. [Copyright &y& Elsevier]

Over the last few decades, several types of evidence such as presence of hominin remains, lithic assemblages, and bones with anthropogenic surface modifications have demonstrated that early human communities inhabited the European subcontinent prior to the Jaramillo Subchron (1.07–0.98 Ma). While most studies have focused primarily on early European lithic technologies and raw material management, relatively little is known about food procurement strategies. While there is some evidence showing access to meat and other animal-based food resources, their mode of acquisition and associated butchery processes are still poorly understood. This paper presents a taphonomic and zooarchaeological analysis of the Fuente Nueva-3 (FN3) (Guadix-Baza, Spain) faunal assemblage, providing a more in-depth understanding of early hominin subsistence strategies in Europe. The present results show that hominins had access to the meat and marrow of a wide range of animal taxa, including elephants, hippopotami, and small- and medium-sized animals. At the same time, evidence of carnivore activity at the site suggests that these communities likely faced some degree of competition from large predators when acquiring and processing carcasses. [ABSTRACT FROM AUTHOR]

Venta Micena is an area containing several palaeontological sites marking the beginning of the Calabrian stage (Early Pleistocene). The richness of the fossil accumulation including species of Asian, African and European origin, makes Venta Micena a key site for the the palaeoecological and palaeoenvironmental study of southern Europe during the Early Pleistocene. Thus, research has been focused on Venta Micena 3, which was originally interpreted as a single palaeosurface associated with a marshy context, in which most of the fauna was accumulated by Pachycrocuta brevirostris. Recent excavations have unearthed a new site, Venta Micena 4, located in the same stratigraphic unit (Unit C) and in close proximity to Venta Micena 3. Here we show the first analyses regarding the taphonomic and spatial nature of this new site, defining two stratigraphic boundaries corresponding to two different depositional events. Furthermore, the taphonomic analyses of fossil remains seem to indicate a different accumulative agent than Pachycrocuta, thus adding more complexity to the palaeobiological interpretation of the Venta Micena area. These results contribute to the discussion of traditional interpretations made from Venta Micena 3. [ABSTRACT FROM AUTHOR]

In their technical comment raise several issues, including an important topic affecting most, or perhaps all, paleoecological studies-the difficulty of determining a reasonable way to deal with taxonomy. Specifically, Salesa et al. draw our attention to a taxonomic revision of Iberian Anchitherium (), that we failed to follow in our study (), and express concerns that a different handling of Anchitherium taxonomy would have affected our results and conclusions. [ABSTRACT FROM AUTHOR]

Aim: The links between geo‐ and biodiversity, postulated by Humboldt, can now be made quantitative. Species are adapted to their environments and interact with their environments by having pertinent functional traits. We aim to improve global ecometric models using functional traits for estimating palaeoclimate and apply models to Pleistocene fauna for palaeoclimate interpretation. Location: Global at present day, Pleistocene of Europe for fossil data analysis. Taxa: Artiodactyla, Perissodactyla, Proboscidea and Primates. Methods: We quantify functional traits of large mammal communities and develop statistical models linking trait distributions to local climate at present day. We apply these models to the fossil record, survey functional traits, and quantitatively estimate climates of the past. This approach to analysing functional relationships between faunal communities and their environments is called ecometrics. Results and main conclusions: Here, we present new global ecometric models for estimating mean annual and minimum temperature from dental traits of present day mammalian communities. We also present refined models for predicting net primary productivity. Using dental ecometric models, we produce palaeoclimate estimates for 50 Pleistocene fossil localities in Europe and show that the estimates are consistent with trends derived from other proxies, especially for minimum temperatures, which we hypothesize to be ecologically limiting. Our new temperature models allow us to trace the distribution of freezing and non‐freezing ecosystems in the recent past, opening new perspectives on the evolution of cold‐adaptive biota as the Pleistocene cooling progressed. [ABSTRACT FROM AUTHOR]

The oldest evidence of a human presence in western Europe is currently documented at the late Early Pleistocene sites of Barranco León and Fuente Nueva 3 (Guadix-Baza Basin, SE Spain), dated respectively to 1.4 and 1.2 Ma. Understanding the climatic variability that these hominins encountered and coped with is of outstanding importance for placing their activities in an ecological context and understanding their capacity to adapt to changing conditions. Glacial-interglacial variability during this period was considerably less intense than during later phases of the Pleistocene. To date, however, no quantitative estimates are available for this climate variability in Early Pleistocene hominin sites, and no 'cold' reconstructions directly associated with the early hominin occupations of Europe have been performed either. Here stratigraphically constrained quantitative climatic reconstructions are provided for the sites of Barranco León and Fuente Nueva 3, using an improvement on the Mutual Ecogeographic Range method by projecting the niche envelope of the extant representatives of Ophisaurus sp. We ascertain differences in temperature and rainfall between the different layers of the two sites, in line with previous reconstructions that revealed warm, humid periods ('interglacial') as well as more temperate but drier periods ('glacial''), consistent with Early Pleistocene climate cyclicity. Our new estimates suggest that late Early Pleistocene hominins, though conditioned to some degree by climatic factors, were able to deal with changing climatic and environmental conditions ('interglacial' and 'glacial'') in the southwestern extremity of the European continent. [Display omitted] • The oldest human evidence in western Europe is currently documented at 1.4 Ma. • Understanding the climatic variability that these hominins encountered is relevant. • Paleoclimatic data are provided for an archaeopaleontological sequence. • The Early Pleistocene hominins were able to cope with changing climatic conditions. [ABSTRACT FROM AUTHOR]

Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Olduvai during Middle Bed II at ∼1.7–1.4 Ma, an interval that captures the local transition from Oldowan to Acheulean technology. We expand the faunal list for this interval, name a new bovid species, clarify the evolution of several mammalian lineages, and record new local first and last appearances. Compositions of the fish and large mammal assemblages support previous indications for the dominance of open and seasonal grassland habitats at the margins of an alkaline lake. Fish diversity is low and dominated by cichlids, which indicates strongly saline conditions. The taphonomy of the fish assemblages supports reconstructions of fluctuating lake levels with mass die-offs in evaporating pools. The mammals are dominated by grazing bovids and equids. Habitats remained consistently dry and open throughout the entire Bed II sequence, with no major turnover or paleoecological changes taking place. Rather, wooded and wet habitats had already given way to drier and more open habitats by the top of Bed I, at 1.85–1.80 Ma. This ecological change is close to the age of the Oldowan-Acheulean transition in Kenya and Ethiopia, but precedes the local transition in Middle Bed II. The Middle Bed II large mammal community is much richer in species and includes a much larger number of large-bodied species (>300 kg) than the modern Serengeti. This reflects the severity of Pleistocene extinctions on African large mammals, with the loss of large species fitting a pattern typical of defaunation or ‘downsizing’ by human disturbance. However, trophic network (food web) analyses show that the Middle Bed II community was robust, and comparisons with the Serengeti community indicate that the fundamental structure of food webs remained intact despite Pleistocene extinctions. The presence of a generalized meat-eating hominin in the Middle Bed II community would have increased competition among carnivores and vulnerability among herbivores, but the high generality and interconnectedness of the Middle Bed II food web suggests this community was buffered against extinctions caused by trophic interactions. [ABSTRACT FROM AUTHOR]

More than half a century ago, Percy Butler touted the importance of analyzing teeth to understand their function in an evolutionary context. There have been many advances in the study of dental functional morphology since that time. Here we review the various approaches to characterizing and comparing occlusal form that have been developed, especially dental topographic analysis. We also report on a new study of dental topography of platyrrhine primates (n = 341 individuals representing 16 species) with known differences in both dietary preferences and other food items eaten. Results indicate frugivores, gummivores, folivores, and seed eaters each have a unique combination of slope, relief, angularity, sharpness, and occlusal orientation patch size and count values. Likewise, among frugivores, those that supplement their diets with hard objects, insects, leaves, and seeds, also each have a distinctive suite of topographic features. We conclude that both primary and secondary diet choices select for occlusal form, and that functional morphology more reflects the types of foods and mechanical challenges they pose rather than the frequencies in which they are eaten. [ABSTRACT FROM PUBLISHER]

Venta Micena (Orce, Guadix-Baza Basin, Spain) is an Early Pleistocene locality renowned for the richness and quality of its palaeontological record. VM is spread over an area of 2.5 km2, where several exposed fossil outcrops are visible amidst its gorges and ravines. The best known of these sites, VM3, has been interpreted as a hyaena den. In addition, a new site, named VM4, has recently been the focus of fieldwork and taphonomic studies. The publication by Luzón et al. (2021) pointed out that VM4 presents a more complex history than VM3. First, two different sub-levels were identified: VM4-I and VM4-II. Secondly, the preliminary taphonomic analysis showed conspicuous differences with regard to VM3. Nevertheless, such interpretation has been challenged by Palmqvist et al. (2022) who proposed that VM3 and VM4 are both the result of a single depositional process, entailing the selective transport of skeletal parts by the giant extinct hyaena Pachycrocuta brevirostris back to its den. Using well-preserved faunal elements whose depositional context and provenance are reliable, in this paper we show that: 1) there are two clearly defined sub-levels in VM4 with some shared taphonomic characteristics as well as some notable differences; 2) VM3 and VM4 exhibit enough divergence to support differences in site formation processes; 3) The interpretation of both VM4-I and VM4-II is more consistent with their characterisation as open-air sites in which multiple agents and depositional processes contributed to its formation, rather than with hyaena dens. Nevertheless, excavations are still in progress at VM4 and therefore any results and interpretations ought to be considered as provisional. • VM3 has been interpreted as a hyaena den. • VM4 presents a more complex history than VM3. • VM4-II, is more consistent with an open-air site. • VM4 is not a carnivore den site. [ABSTRACT FROM AUTHOR]

Damiao, Inner Mongolia, has three main fossil horizons representing the early, middle, and late Miocene. The middle Miocene locality DM01 is the only primate locality from the region and also represents the latest occurrence of pliopithecoids in northern China. The presence of pliopithecoid primates in central Asia after the middle Miocene climatic optimum seems to contradict the general trend of strengthening climatic zonality and increasing aridity. To investigate this enigma, we employ faunal similarity, ecometrics, and stable isotope analysis. Our results support previous inferences concerning the presence of locally humid environments within the increasingly arid surroundings that characterized central Asia. Hypsodonty, estimated mean annual precipitation (MAP), local sedimentology, and large mammal fossils suggest more humid and possibly more forested and wooded environments for the DM01 locality. We compared our results with the adjacent fossil-rich middle Miocene Tunggur localities. However, the small mammal fauna and isotope data are consistent with a mosaic of forest and grassland environment for all Damiao localities. Based on our results, Tunggur may have been too seasonal or not sufficiently humid for pliopithecids. This is supported by the higher mean hypsodonty and lower estimated MAP estimates, as well as slightly higher δ 13 C values. We suggest that DM01, the driest known Asian pliopithecid locality, may have been a more humid refugium within a generally drier regional context. [ABSTRACT FROM AUTHOR]

We discuss a proboscidean bone fragment discovered in southern Finland, including the morphological analysis of the bone, as well as pollen and diatom analyses from sediment contained in the marrow cavity. Preliminary analysis of the bone suggested petrification and thus an apparently old age, while the microfossil assemblages include numerous unequivocally pre-Quaternary pollen, spore, and diatom types. A Miocene age for the bone is determined based on the presence of the diatom genus Alveolophora , indicating a minimum age of 5 Ma, and based on the earliest appearance of proboscideans outside Africa, setting a maximum age of 19 Ma. Based on morphology, the bone is determined as a partial humerus of the left foreleg of a large proboscidean. The bone is tentatively assigned to cf. Deinotherium sp., which is consistent with the diatom-based minimum age. The pollen assemblage is rich in spores of shoreline pteridophytes, while the diatom assemblage is also consistent with a shoreline freshwater environment, suggesting that the bone was deposited post-mortem near the shore of a lake or a stream. Miocene sediments do not currently exist in southern Finland or in the near vicinity. This implies that the bone has been transported over a considerable distance. Due to the discovery of the bone in early-Holocene Baltic Sea clay, the final transport phase and deposition must have taken place via iceberg rafting. This was likely preceded by one or more phases of glacial and/or glacio-fluvial transport. While we are unable to conclusive ascertain the region of origin, the alkaline composition of the contained sediment and diatoms point towards the Russian Plain region in the east. This specimen represents the oldest mammalian bone discovered in Finland and the northernmost discovery of a Miocene proboscidean bone in Europe. [ABSTRACT FROM AUTHOR]

Palynological investigations in the Orce Archaeological Zone (OAZ) (Guadix-Baza Basin, Granada, Spain), Venta Micena 1 (VM1), Barranco León (BL) and Fuente Nueva 3 (FN3) are presented. This archaeological region is connected with the first Homo populations in Western Eurasia during the Early Pleistocene. The VM1 pollen record is characterized by Ephedra , and to a lesser extent, Pinus , Juniperus and evergreen Quercus , occassionally accompanied by Olea , Genisteae, Erica , deciduous Quercus , Alnus , Castanea , Fraxinus , Salix and Phillyrea. BL is dominated by Juniperus , Olea , Pinus , Poaceae, and evergreen Quercus. FN3 is characterized by an open Mediterranean woodland dominated by evergreen Quercus, Pinus, Juniperus and Olea , accompanied by deciduous Quercus , Castanea , Populus , Salix , Ulmus, Fraxinus , Pistacia , Phillyrea , Genisteae, Erica , Cistus , and Ephedra fragilis. Relic Tertiary taxa in OAZ include Carya, Pterocarya, Eucommia, Zelkova , and Juglans. The Early Pleistocene OAZ vegetation is a mosaic of different landscapes embracing mesophytes, thermophytes, xerophytes, xerothermophytes, and Mediterranean elements. These finds are compared with former pollen analyses in the region and beyond within the Iberian Peninsula. • Pollen help reconstruct Early Pleistocene vegetation in the Orce Archaeological sites. • Venta Micena, Barrranco León and Fuente Nueva sites, southern Spain, have been studied. • New palaeoecological data for the first Homo populations in Western Eurasia. • The Early Pleistocene vegetation in the OAZ is a mosaic of different landscapes. • The vegetation of the first Homo included forested areas with high plant diversity. [ABSTRACT FROM AUTHOR]

The spatiotemporal pattern of the late Cenozoic spread of C 4 vegetation is an important indicator of environmental change that is intertwined with the uplift of the Himalaya and Tibetan Plateau, and the development of the East Asian monsoons. To explore the spread of C 4 vegetation in China and shed new light on regional climatic evolution, we measured δ 13 C values of more than 200 small mammal teeth (primarily rodents and lagomorphs) using a laser ablation isotope ratio mass spectrometry approach. Small mammals are highly sensitive indicators of their environment because they have limited spatial ranges and because they have minimal time-averaging of carbon isotope signatures of dietary components. The specimens originate from four classic Late Miocene fossil localities, Lufeng, Yuanmou, Lingtai, and Ertemte, along a southwest-northeast transect from Yunnan Province to Inner Mongolia. In Yunnan (Lufeng, Yuanmou) and on the Loess Plateau (Lingtai), the small mammal δ 13 C values record nearly pure C 3 ecosystems, and mixed but C 3 -based ecosystems, respectively, in agreement with previous studies based on carbon isotopes of large herbivores and soil carbonates. In Inner Mongolia, the micromammalian tooth enamel δ 13 C record picks up the presence of C 4 vegetation where large mammal samples do not, indicating a mixed yet C 3 -dominated ecosystem at ~ 6 Ma. As a whole, the results support a scenario of northward increasing C 4 grass abundance in a pattern that mirrors northward decreasing precipitation of the summer monsoon system. The results highlight differences between large and small mammals as indicators of C 4 vegetation in ancient ecosystems, particularly the ability of small mammal δ 13 C values to detect the presence of minor components of the vegetation structure. [ABSTRACT FROM AUTHOR]

Luxuriant, bushy antlers, bizarre crests, and huge, twisting horns and tusks are conventionally understood as products of sexual selection. This view stems from both direct observation and from the empirical finding that the size of these structures grows faster than body size (i.e., ornament size shows positive allometry).We contend that the familiar evolutionary increase in the complexity of ornaments over time in many animal clades is decoupled from ornament size evolution. Increased body size comes with extended growth. Since growth scales to the quarter power of body size, we predicted that ornament complexity should scale according to the quarter power law as well, irrespective of the role of sexual selection in the evolution and function of the ornament. To test this hypothesis, we selected three clades (ammonites, deer, and ceratopsian dinosaurs) whose species bore ornaments that differ in terms of the importance of sexual selection to their evolution.We found that the exponent of the regression of ornament complexity to body size is the same for the three groups and is statistically indistinguishable from0.25.We suggest that the evolution of ornament complexity is a by-product of Cope's rule. We argue that although sexual selection may control size in most ornaments, it does not influence their shape. [ABSTRACT FROM AUTHOR]

Since the discovery of mammalian fossils in Central Inner Mongolia in the beginning of the 20th century, this area has produced a rich and diverse record of Miocene faunas. Nevertheless, the stratigraphy has remained poorly constrained owing to scattered faunal horizons and lack of continuous vertical exposures. Consequently, most age estimates of these Miocene sites are based on paleontological evidence alone, with very few sites having been dated independently. Our field investigations in Damiao, in Siziwang Qi, Inner Mongolia have yielded more than 30 new fossiliferous localities from three horizons, including a pliopithecid fauna. This study presents the litho-, bio- and magnetostratigraphy of the Damiao area and provides age estimates for the three fossil-bearing horizons. The sedimentary sequence is interpreted as the remains of a fluvial system comprising channels, subaerially exposed floodplains and floodbasin environments. The two local stratigraphic sections measured and sampled for paleomagnetic analysis coincide with species-rich vertebrate fossil localities. The paleomagnetic results and faunal evidence suggest a correlation of lowermost fossil horizon (DM16) producing relatively rich small mammal assemblage to the early Miocene chron C6Ar or C6An.1r, roughly in 20–21 Ma age range. The pliopithecid locality level (DM01) represents latest middle Miocene and has an age estimate of about 12.1 Ma while the youngest localities (DM02) with cervoids and abundant and diverse small mammal fauna represents the earliest late Miocene with an age estimate of about 11.6 Ma. Our magnetostratigraphic results confirm that the Damiao strata constitute one of the best sequences in Inner Mongolia with early, middle and late Miocene mammalian faunas in stratigraphic superposition. The results also provide constraints on the paleoenvironmental evolution and bioevents of the area. The occurrence of pliopithecid primates in the middle Miocene of Inner Mongolia suggests humid habitats and challenges the scenarios suggesting arid and highly seasonal conditions for Central Asia since Early Miocene. The presence of pliopithecids may also bear witness to locally humid environments and greater habitat heterogeneity than previously known in central Inner Mongolia. [ABSTRACT FROM AUTHOR]

Aim To propose a unified framework for quantifying taxon ( Tβ), phylogenetic ( Pβ) and functional ( Fβ) beta diversity via pairwise comparisons of communities, which allows these types of beta diversity to be partitioned into ecologically meaningful additive components. Location Global, with case studies in Europe and the Azores archipelago. Methods Using trees as a common representation for taxon, phylogenetic and functional diversity, we partition total beta diversity (βtotal) into its replacement (turnover, βrepl) and richness difference (βrich) components according to which part of a global tree was shared by or unique to communities that were being compared. We demonstrate the application of this framework using artificial and empirical examples (mammals in Europe and epigean arthropods in the Azores). Results Our empirical examples show that comparing Pβ and Fβ with the most commonly used Tβ revealed previously hidden patterns of beta diversity. More importantly, we demonstrate that partitioning Pβtotal and Fβtotal into their respective βrepl and βrich components facilitates the detection of more complex patterns than using the overall coefficients alone, further elucidating the different forces operating in community assembly. Main conclusions The methods presented here allow the integration and full comparison of Tβ, Pβ and Fβ. They provide a tool for effectively disentangling the replacement (turnover) and richness difference components of the different biodiversity facets within the same methodological framework. [ABSTRACT FROM AUTHOR]

The evolution of a particular sensory organ is often discussed with no consideration of the roles played by other senses. Here, we treat mammalian vision, olfaction and hearing as an interconnected whole, a three-dimensional sensory space, evolving in response to ecological challenges. Until now, there has been no quantitative method for estimating how much a particular animal invests in its different senses. We propose an anatomical measure based on sensory organ sizes. Dimensions of functional importance are defined and measured, and normalized in relation to animal mass. For 119 taxonomically and ecologically diverse species, we can define the position of the species in a three-dimensional sensory space. Thus, we can ask questions related to possible trade-off vs. co-operation among senses. More generally, our method allows morphologists to identify sensory organ combinations that are characteristic of particular ecological niches. After normalization for animal size, we note that arboreal mammals tend to have larger eyes and smaller noses than terrestrial mammals. On the other hand, we observe a strong correlation between eyes and ears, indicating that co-operation between vision and hearing is a general mammalian feature. For some groups of mammals we note a correlation, and possible co-operation between olfaction and whiskers. [ABSTRACT FROM AUTHOR]

It has been demonstrated in climate models that both the Indian and East Asian summer monsoons (ISM and EASM) are strengthened by the uplift of the entire Asian orography or Tibetan Plateau (TP) (i.e. bulk mountain uplift). Such an effect is widely perceived as the major mechanism contributing to the evolution of Asian summer monsoons in the Neogene. However, geological evidence suggests more diachronous growth of the Asian orography (i.e. regional mountain uplift) than bulk mountain uplift. This demands a re-evaluation of the relation between mountain uplift and the Asian monsoon in the geological periods. In this study, sensitivity experiments considering the diachronous growth of different parts of the Asian orography are performed using the regional climate model COSMO-CLM to investigate their effects on the Asian summer monsoons. The results show that, different from the bulk mountain uplift, the regional mountain uplift can lead to an asynchronous development of the ISM and EASM. While the ISM is primarily intensified by the thermal insulation (mechanical blocking) effect of the southern TP (Zagros Mountains), the EASM is mainly enhanced by the surface sensible heating of the central, northern and eastern TP. Such elevated surface heating can induce a low-level cyclonic anomaly around the TP that reduces the ISM by suppressing the lower tropospheric monsoon vorticity, but promotes the EASM by strengthening the warm advection from the south of the TP that sustains the monsoon convection. Our findings provide new insights to the evolution of the Asian summer monsoons and their interaction with the tectonic changes in the Neogene. [ABSTRACT FROM AUTHOR]

Data, whether images, measurements, counts, occurrences, or character codings, are a cornerstone of vertebrate paleontology. Every published paper, master's thesis, and doctoral dissertation relies on these data to document patterns and processes in evolution, ecology, taphonomy, geography, geologic time, and functional morphology, to name just a few. In turn, the vertebrate paleontology community relies on published data in order to reproduce and verify others’ work, as well as to expand upon published analyses in new ways without having to reconstitute data sets that have been used by earlier authors and to accurately preserve data for future generations of researchers. Here, we review several databases that are of interest to vertebrate paleontologists and strongly advocate for more deposition of basic research data in publicly accessible databases by vertebrate paleontologists. [ABSTRACT FROM PUBLISHER]

Aim Our aims were to test: (1) the extent to which vascular plant associations are related in space to mammalian associations, and (2) whether the plant associations are more closely related than the mammalian associations to climate and to a published environmental stratification of Europe. Location Europe, as defined by the following boundaries: 11° W, 32° E, 71° N and 35° N. Methods The analysis is based on presence/absence records of mammal species and plant species with a resolution of 50 km × 50 km. The similarity of the overall spatial structure was tested using a partial Mantel test while controlling for the effect of geographical proximity. To further identify the main spatial components in the datasets, we used k-means clustering and principal components analysis. The resulting geographical patterns were compared with one another, with climate variables and with the environmental stratification of Europe. Results The clustering of the plant data forms coherent areas that can be interpreted as reflections of floristic regions that are controlled to a large extent by climate and topography. In terms of the correlation between distance matrices, the relationship between plants and mammals is relatively strong. The relationships between mammals and climate, and between plants and climate, are more complex but always statistically significant. There is no evidence that the plant clusters are more closely related than the mammalian clusters to climate, although plant clusters are closer to environmental data than to climate. Main conclusions The clustering patterns of mammals and plants form groups that agree with one another in their spatial extent. The forcing of floristic patterns into coherent entities appears mainly to be caused by climatic variables (temperature, temperature range and rainfall), mediated by elevation differences. The formation of individual plant clusters is also related to species numbers and to local and regional floristic differences. The close correlation between the floristic and faunal patterns suggests that the mammal and plant distributions are controlled by the same environmental variables, although the extent to which the mammals are controlled directly by climate or through the influence of vegetation requires more detailed study. [ABSTRACT FROM AUTHOR]

We have recently shown that rainfall, one of the main climatic determinants of terrestrial net primary productivity (NPP), can be robustly estimated from mean molar tooth crown height (hypsodonty) of mammalian herbivores. Here, we show that another functional trait of herbivore molar surfaces, longitudinal loph count, can be similarly used to extract reasonable estimates of rainfall but also of temperature, the other main climatic determinant of terrestrial NPP. Together, molar height and the number of longitudinal lophs explain 73 per cent of the global variation in terrestrial NPP today and resolve the main terrestrial biomes in bivariate space. We explain the functional interpretation of the relationships between dental function and climate variables in terms of long- and short-term demands. We also show how the spatially and temporally dense fossil record of terrestrial mammals can be used to investigate the relationship between biodiversity and productivity under changing climates in geological time. The placement of the fossil chronofaunas in biome space suggests that they most probably represent multiple palaeobiomes, at least some of which do not correspond directly to any biomes of today's world. [ABSTRACT FROM AUTHOR]

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a planetary-scale 'tipping point' highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes. [ABSTRACT FROM AUTHOR]

The Cretaceous-Paleogene mass extinction approximately 66 million years ago is conventionally thought to have been a turning point in mammalian evolution. Prior to that event and for the first two-thirds of their evolutionary history, mammals were mostly confined to roles as generalized, small-bodied, nocturnal insectivores, presumably under selection pressures from dinosaurs. Release from these pressures, by extinction of non-avian dinosaurs at the Cretaceous-Paleogene boundary, triggered ecological diversification of mammals. Although recent individual fossil discoveries have shown that some mammalian lineages diversified ecologically during the Mesozoic era, comprehensive ecological analyses of mammalian groups crossing the Cretaceous-Paleogene boundary are lacking. Such analyses are needed because diversification analyses of living taxa allow only indirect inferences of past ecosystems. Here we show that in arguably the most evolutionarily successful clade of Mesozoic mammals, the Multituberculata, an adaptive radiation began at least 20 million years before the extinction of non-avian dinosaurs and continued across the Cretaceous-Paleogene boundary. Disparity in dental complexity, which relates to the range of diets, rose sharply in step with generic richness and disparity in body size. Moreover, maximum dental complexity and body size demonstrate an adaptive shift towards increased herbivory. This dietary expansion tracked the ecological rise of angiosperms and suggests that the resources that were available to multituberculates were relatively unaffected by the Cretaceous-Paleogene mass extinction. Taken together, our results indicate that mammals were able to take advantage of new ecological opportunities in the Mesozoic and that at least some of these opportunities persisted through the Cretaceous-Paleogene mass extinction. Similar broad-scale ecomorphological inventories of other radiations may help to constrain the possible causes of mass extinctions. [ABSTRACT FROM AUTHOR]

How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous—Paleogene (K—Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes. [ABSTRACT FROM AUTHOR]

The article discusses a study which estimated the species richness from climate and environmental variables across spatial scales using 10-kilometer grid data from Finnish Bird Atlas. Ordinary least squares (OLS) linear-regression model with a quadratic error function was used to estimate the occurring number of bird species. The study found that the length of the growing season with R squared values is the best estimator for avian species richness in Finland.