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Demonstrating the process of transregional biogeography and mechanisms underlying evolutionary radiations is crucial to understanding biological evolution. Here, we use Hydrangeeae (Hydrangeaceae), a tribe with a unique disjunct distribution and complex trait variations, using a solid phylogenetic framework, to investigate how geographical and climatic factors interact with functional traits to trigger plant evolutionary radiations. We constructed the first highly supported and dated phylogenetic framework using 79 protein-coding genes obtained from 81 plastomes, representing 63 species and all major clades, and found that most extant species originated from asynchronous diversification of two lineages undergoing repeated expansion and retraction, at middle and high latitudes of the Northern Hemisphere between East Asia and North America, during the Eocene to Pleistocene (driven by geologic and climatic dynamics). In accordance with these drivers, interactions of flora between central-eastern China and Japan occurred frequently after the Late Tertiary. We found that resource limitation and range fragmentation probably accelerated the diversification of Hydrangeeae, which supports the resource-use hypothesis. Our study sheds light on the evolutionary radiation and assembly of flora within East Asia, and the East Asian–North American disjunction, through integration of phylogenomic and biogeographic data with functional trait and ecological data. [ABSTRACT FROM AUTHOR]

Aim: The Late Cenozoic flourishing of polar marine ecosystems, just when temperatures were reaching their lowest levels, has always seemed anomalous. Such an observation is coupled with an increasing volume of molecular phylogenetic evidence to indicate that some polar taxa radiated at exceptionally high evolutionary rates. The canonical latitudinal diversity gradient (LDG) may not be underpinned by a parallel gradient in evolutionary rates. This study provides a review of this critical question. Location: A variety of polar – tropical comparisons are made, with some emphasis on the Southern Ocean. Taxa: Both marine and terrestrial taxa are used, with some emphasis on marine Mollusca. Methods: High – low latitude comparisons of evolutionary rates over the last 66 Myr are made using two approaches: rates derived from molecular phylogenies, and rates derived from the fossil record. For the former of these data are taken from various marine and terrestrial taxa, and for the latter use is made of the excellent fossil record of marine Mollusca. Results: For approximately the first half of the Cenozoic era (i.e., 66 Ma onwards) there is strong palaeontological evidence to suggest that the global LDG developed in a conventional way, with higher rates of origination in the tropics than at the poles. However, there then appears to have been a marked change in the latter half of the Cenozoic when origination rates increased in the high‐latitude and polar regions. The modern latitudinal diversity gradient may be a fossil feature that formed in the Early Cenozoic. Main Conclusions: As the extra‐tropical regions expanded through the Cenozoic they provided increasingly more ecological opportunities for a wide variety of marine and terrestrial taxa. Substantially lower temperatures in the polar regions were clearly not an obstacle to spectacular evolutionary radiations such as that based on the krill ecosystem. [ABSTRACT FROM AUTHOR]

The article describes the paleobiogeographic history of the modern subfamilies so-called “crown deer” of the family Cervidae (Artiodactyla, Mammalia) in the world from the late Miocene to the late Pleistocene. The study overviews the taxonomic diversity and evolutionary radiation of Cervidae from all zoogeographic realms where this systematic group is present in the paleontological record. The evolutionary diversification of the fossil Cervidae is based on the estimations of species body masses that are regarded here as a proxy of occupied ecological niches. The study reveals two important evolutionary radiations of Cervidae during the late Miocene of Eurasia that gave the origin of the modern subfamilies Cervinae and Capreolinae. The evolutionary radiation of Capreolinae during the Pleistocene in South America shows a range of diversity comparable to the late Miocene radiations of Old World deer and provides multiple examples of evolutionary convergences with Eurasian Pleistocene cervids. The article discusses factors that shaped the modern biogeographic distribution of representatives of the subfamilies Cervinae and Capreolinae.

Aim: Groundwater harbours an exceptional fauna and provides invaluable ecosystem services, yet is among the least explored and consequently least protected ecosystems. Successful protection of its biodiversity depends on complete species inventories, knowledge of species spatial distribution, and quantification of biodiversity patterns, as well as disentanglement of the processes that shaped biodiversity patterns. We studied the hyper‐speciose amphipod genus Niphargus as a model system within a global subterranean biodiversity hotspot. We linked the biodiversity patterns with possible underlying processes and discuss the needs to include information on different origins of biodiversity into conservation approaches. Location: Europe, Western Balkans. Methods: We analysed biodiversity patterns of Niphargus using two biodiversity metrics, species richness and phylogenetic diversity, on a grid‐based approach. To account for high cryptic diversity, we replaced nominal species with taxonomic units identified in unilocus delimitations (MOTUs). We built a time‐calibrated multilocus phylogeny of 512 Niphargus MOTUs from within and outside the study area, and calculated Faith's phylogenetic diversity, standardized effect sizes of phylogenetic diversity, and residual of phylogenetic diversity regressed onto species richness. Results: Within the study area, we recognized 245 MOTUs, belonging to different Niphargus clades. Species richness is highest in a north‐western hotspot, although some species‐rich cells were detected also in the south‐east. High phylogenetic diversity coincides with high species richness in the north‐west, while in the south‐east it is lower than expected. Main conclusions: We have shown that species richness does not predictably correlate with phylogenetic diversity. This difference suggests that different processes have led to the formation of species‐rich areas in the Western Balkans: through a combination of dispersal and speciation in the north‐west, and local radiation in the south‐east, respectively. This calls for caution in conservation strategies relying solely on number of species and may change the view on conservation priorities within this region. [ABSTRACT FROM AUTHOR]

The article describes the paleobiogeographic history of the modern subfamilies so-called "crown deer" of the family Cervidae (Artiodactyla, Mammalia) in the world from the late Miocene to the late Pleistocene. The study overviews the taxonomic diversity and evolutionary radiation of Cervidae from all zoogeographic realms where this systematic group is present in the paleontological record. The evolutionary diversification of the fossil Cervidae is based on the estimations of species body masses that are regarded here as a proxy of occupied ecological niches. The study reveals two important evolutionary radiations of Cervidae during the late Miocene of Eurasia that gave the origin of the modern subfamilies Cervinae and Capreolinae. The evolutionary radiation of Capreolinae during the Pleistocene in South America shows a range of diversity comparable to the late Miocene radiations of Old World deer and provides multiple examples of evolutionary convergences with Eurasian Pleistocene cervids. The article discusses factors that shaped the modern biogeographic distribution of representatives of the subfamilies Cervinae and Capreolinae. [ABSTRACT FROM AUTHOR]

This study documents the distribution of matgrounds in a wide variety of environments recorded in the Ordovician Lashkerak and Ghelli Formations in the Alborz Mountains of northern Iran in order to evaluate controls on their distribution along the marine depositional profile. Detailed facies analysis allowed differentiating three groups of facies associations in the Lower to Upper Ordovician deposits of the Lashkerak formation: (i) estuarine system; (ii) wave‐dominated shoreface‐offshore complex; and (iii) mixed river‐ and wave‐influenced deltaic system. The Middle to Upper Ordovician deposits of the Ghelli formation are divided into two groups of facies associations: (i) tide‐influenced deltaic succession and (ii) deep‐water fan system. Microbially induced sedimentary structures (MISS) are present in deposits formed in the central estuarine basin (Lashkerak formation) and in proximal lobes and lobe fringes of deep–water turbidite fans (Ghelli formation). On the contrary, MISS are absent in deposits from the wave‐dominated shoreface‐offshore complex, river‐ and tide‐dominated deltas, and various subenvironments of the incised wave‐dominated estuary (i.e., bayhead delta and estuary mouth) and the deep‐marine turbidite fan system (i.e., turbidite channel, slope, and outer lobe). The lack of evidence of mat‐building microorganisms in the deltaic systems may have resulted from two factors: (1) high physico‐chemical stressors caused by river‐induced processes, and (2) increase in degree of sediment disturbance, biodiffusion, and bioirrigation by burrowing organisms. Formation of microbial mats in the wave‐dominated shoreface‐offshore complex was inhibited by the activity of an abundant and diverse infauna capable of reworking the sediment. Our analysis shows that the spatial distribution of microbial mats was controlled by an interplay of environmental factors and innovations in animal‐substrate interactions, mostly expressed by secular changes in bioturbation. This study supports the notion that the agronomic revolution was diachronic, with marginal‐marine and deep‐sea ecosystems lagging behind shallow‐marine settings. [ABSTRACT FROM AUTHOR]

Abstract Background A large number of taxa have undergone evolutionary radiations in mountainous areas, rendering alpine systems particularly suitable to study the extrinsic and intrinsic factors that have shaped diversification patterns in plants. The species-rich genus Saxifraga L. is widely distributed throughout the Northern Hemisphere, with high species numbers in the regions adjacent to the Qinghai-Tibet Plateau (QTP) in particular the Hengduan Mountains and the Himalayas. Using a dataset of 297 taxa (representing at least 60% of extant Saxifraga species), we explored the variation of infrageneric diversification rates. In addition, we used state-dependent speciation and extinction models to test the effects of geographic distribution in the Hengduan Mountains and the entire QTP region as well as of two morphological traits (cushion habit and specialized lime-secreting glands, so-called hydathodes) on the diversification of this genus. Results We detected two to three rate shifts across the Saxifraga phylogeny and two of these shifts led to radiations within two large subclades of Saxifraga, sect. Ciliatae Haworth subsect. Hirculoideae Engl. & Irmsch. and sect. Porphyrion Tausch subsect. Kabschia Engl. GEOSSE analyses showed that presence in the Hengduan Mountains had a positive effect on diversification across Saxifraga. Influence of these mountains was strongest in Saxifraga sect. Ciliatae subsect. Hirculoideae given its pronounced distribution there, and thus the radiation in this group can be classified at least partially as geographic. In contrast, the evolution of the cushion life form and lime-secreting hydathodes had positive effects on diversification only in selected Saxifraga sections, including sect. Porphyrion subsect. Kabschia. We therefore argue that radiation in this group was likely adaptive. Conclusions Our study underlines the complexity of processes and factors underpinning plant radiations: Even in closely related lineages occupying the same life zone, shifts in diversification are not necessarily governed by similar factors. In conclusion, alpine plant radiations result from a complex interaction among geographical settings and/or climatic modifications providing key opportunities for diversification as well as the evolution of key innovations.

Cushion plants exhibiting adaptive convergence in cold and dry environments are keystone and foundation species in the alpine/subnival habitat on the Qinghai‐Tibet Plateau (QTP). To date, little attention has been paid to the molecular phylogeny, origin, and biogeography of cushion plants on the QTP. We investigated the molecular phylogeny of classic cushion Arenaria subg. Dolophragma, A. subg. Eremogoneastrum, and Thylacospermum on the QTP, within the framework of the Caryophyllaceae. A new Thylacospermum‐Dolophragma clade was identified using combined plastid markers (rps16, matK, trnL‐trnF, trnS‐trnfM) and nuclear ribosomal DNA. Molecular divergence dating suggested that Thylacospermum and A. subg. Dolophragma originated in the middle to late Miocene (11.68 Ma). Combined with ancestral range reconstruction, there is an indication that all species of cushion Arenaria (A. subg. Dolophragma, A. subg. Eremogoneastrum) originated during/after the late Pliocene, and the QTP was their ancestral area. Furthermore, ecological niche modeling showed that the areas occupied by the three studied cushion plants during the last glacial maximum (LGM) was broader than that of their present distribution, implying a reduction in their range after the LGM. This evidence clearly illustrates that multistage uplift of the QTP and bordering mountains since the Miocene associated with climatic change (worldwide cooling, aridification in Central Asia, Quaternary glaciation) played a role in triggering and facilitating the speciation and/or evolutionary radiations of the species studied. [ABSTRACT FROM AUTHOR]

Aim: To quantify the effect of Pleistocene climate fluctuations on habitat connectivity across páramos in the Northern Andes. Location: Northern Andes. Methods: The unique páramos habitat underwent dynamic shifts in elevation in response to changing climate conditions during the Pleistocene. The lower boundary of the páramos is defined by the upper forest line, which is known to be highly responsive to temperature. Here, we reconstruct the extent and connectivity of páramos over the last 1 million years (Myr) by reconstructing the upper forest line from the long fossil pollen record of Funza09, Colombia, and applying it to spatial mapping on modern topographies across the Northern Andes for 752 time slices. Data provide an estimate of how often and for how long different elevations were occupied by páramos and estimate their connectivity to provide insights into the role of topography in biogeographical patterns of páramos. Results: Our findings show that connectivity amongst páramos of the Northern Andes was highly dynamic, both within and across mountain ranges. Connectivity amongst páramos peaked during extreme glacial periods but intermediate cool stadials and mild interstadials dominated the climate system. These variable degrees of connectivity through time result in what we term the 'flickering connectivity system'. We provide a visualization (video) to showcase this phenomenon. Patterns of connectivity in the Northern Andes contradict patterns observed in other mountain ranges of differing topographies. Main conclusions: Pleistocene climate change was the driver of significant elevational and spatial shifts in páramos causing dynamic changes in habitat connectivity across and within all mountain ranges. Some generalities emerge, including the fact that connectivity was greatest during the most ephemeral of times. However, the timing, duration and degree of connectivity varied substantially among mountain ranges depending on their topographical configuration. The flickering connectivity system of the páramos uncovers the dynamic settings in which evolutionary radiations shaped the most diverse alpine biome on Earth. [ABSTRACT FROM AUTHOR]

Background: Balaenopterid mysticetes represent the most successful family-rank group of this clade. Their evolutionary history is characterized by a rich fossil record but the origin of the living genera is still largely not understood. Recent discoveries in the southern border of the North Sea revealed a number of well preserved fossil balaenopterid whales that may help resolving this problem. In particular, skull NMR 14035 shares morphological characters with the living humpback whale, Megaptera novaeangliae and, for this reason, its characteristics are investigated here. Methods: The comparative anatomical analysis of the new specimen formed the basis of a new phylogenetic analysis of the Mysticeti based on a matrix including 350 morphological character states scored for 82 Operational Taxonomic Units. The stratigraphic age of the specimen was determined based on the analysis of the dinocyst assemblage recovered in the associated sediment. We assessed clade diversity in Balaenopteridae by counting the numbers of clades in given time intervals and then plotted the results. Results: Nehalaennia devossi n. gen. et sp. is described for the first time from the late Tortonian (8.7–8.1 Ma) of the Westerschelde (The Netherlands). This new taxon belongs to Balaenopteridae and shows a surprisingly high number of advanced characters in the skull morphology. Nehalaennia devossi is compared to a large sample of balaenopterid mysticetes and a phylogenetic analysis placed it as the sister group of a clade including the genus Archaebalaenoptera. The inclusion of this fossil allowed to propose a phylogenetic hypothesis for Balaenopteridae in which (1) Eschrichtiidae (gray whales) represents a family of its own, (2) Balaenopteridae + Eschrichtiidae form a monophyletic group (superfamily Balaenopteroidea), (3) Cetotheriidae is the sister group of Balaenopteroidea, (4) living Balaenoptera species form a monophyletic group and (5) living M. novaeangliae is the sister group of Balaenoptera. Our work reveals a complex phylogenetic history of Balaenopteridae and N. devossi informs us about the early morphological transformations in this family. Over time, this family experienced a number of diversity pulses suggesting that true evolutionary radiations had taken place. The paleoecological drivers of these pulses are then investigated. [ABSTRACT FROM AUTHOR]

Characterization of evolutionary radiations benefits from describing the temporal patterns of trait disparification. Comparative methods attempt this by evaluating the statistical fit of trait distributions to a phylogenetic hypothesis under assumed evolutionary models. However, it can be challenging to differentiate between models, with discriminatory power depending on the modes of evolution underlying trait distributions. We suggest rates of ‘trait space saturation’, standardized for limits to evolutionary change, as an additional tool to distinguish between modes of trait evolution. We evaluate this approach using simulations and show that trait space saturation can identify the true model of trait evolution in cases where traditional comparative methods can fail. We illustrate our approach using diverse empirical studies that represent contrasting scenarios of evolutionary radiation. [ABSTRACT FROM AUTHOR]

Abstract: We are beginning to appreciate that the origin of the modern Antarctic marine fauna is related to a series of key events throughout the Cenozoic era. In the first of these, the mass extinction at the Cretaceous–Palaeogene boundary (66 Ma) reset the evolutionary stage and led to a major radiation of modern taxa in the benthic realm. Although this took place in a greenhouse world, there is evidence to suggest that the radiation was tempered by the seasonality of primary productivity, and this may be a time‐invariant feature of the polar regions. Although there could well have been a single, abrupt extinction event at c. 34 Ma, there is also evidence to suggest a phased extinction of various taxa over a period of millions of years. Important new molecular phylogenetic data are indicating that a wide variety of both benthic and pelagic taxa radiated shortly after a second major phase of cooling at c. 14 Ma. Such a phenomenon is linked to a series of major palaeoceanographic changes, which in turn led to a proliferation of diatom‐based ecosystems. Although the modern benthic marine fauna can be traced back some 45–50 Myr, a substantial component of the modern pelagic one may be less than 14 Myr old. The latter is also characterized by assemblages of high abundance but comparatively low species richness and evenness. A distinctive signature of low diversity but high dominance within Antarctic marine assemblages was maintained by the interplay between temperature and primary productivity throughout the Cenozoic. [ABSTRACT FROM AUTHOR]

Background: A large number of taxa have undergone evolutionary radiations in mountainous areas, rendering alpine systems particularly suitable to study the extrinsic and intrinsic factors that have shaped diversification patterns in plants. The species-rich genus Saxifraga L. is widely distributed throughout the Northern Hemisphere, with high species numbers in the regions adjacent to the Qinghai-Tibet Plateau (QTP) in particular the Hengduan Mountains and the Himalayas. Using a dataset of 297 taxa (representing at least 60% of extant Saxifraga species), we explored the variation of infrageneric diversification rates. In addition, we used state-dependent speciation and extinction models to test the effects of geographic distribution in the Hengduan Mountains and the entire QTP region as well as of two morphological traits (cushion habit and specialized lime-secreting glands, so-called hydathodes) on the diversification of this genus. Results: We detected two to three rate shifts across the Saxifraga phylogeny and two of these shifts led to radiations within two large subclades of Saxifraga, sect. Ciliatae Haworth subsect. Hirculoideae Engl. & Irmsch. and sect. Porphyrion Tausch subsect. Kabschia Engl. GEOSSE analyses showed that presence in the Hengduan Mountains had a positive effect on diversification across Saxifraga. Influence of these mountains was strongest in Saxifraga sect. Ciliatae subsect. Hirculoideae given its pronounced distribution there, and thus the radiation in this group can be classified at least partially as geographic. In contrast, the evolution of the cushion life form and lime-secreting hydathodes had positive effects on diversification only in selected Saxifraga sections, including sect. Porphyrion subsect. Kabschia. We therefore argue that radiation in this group was likely adaptive. Conclusions: Our study underlines the complexity of processes and factors underpinning plant radiations: Even in closely related lineages occupying the same life zone, shifts in diversification are not necessarily governed by similar factors. In conclusion, alpine plant radiations result from a complex interaction among geographical settings and/or climatic modifications providing key opportunities for diversification as well as the evolution of key innovations. [ABSTRACT FROM AUTHOR]

Contrasts between the Cambrian Explosion (CE) and the Great Ordovician Biodiversification Event (GOBE) have long been recognized. Whereas the vast majority of body plans were established as a result of the CE, taxonomic increases during the GOBE were manifested at lower taxonomic levels. Assessing changes of ichnodiversity and ichnodisparity as a result of these two evolutionary events may shed light on the dynamics of both radiations. The early Cambrian (series 1 and 2) displayed a dramatic increase in ichnodiversity and ichnodisparity in softground communities. In contrast to this evolutionary explosion in bioturbation structures, only a few Cambrian bioerosion structures are known. After the middle to late Cambrian diversity plateau, ichnodiversity in softground communities shows a continuous increase during the Ordovician in both shallow- and deep-marine environments. This Ordovician increase in bioturbation diversity was not paralleled by an equally significant increase in ichnodisparity as it was during the CE. However, hard substrate communities were significantly different during the GOBE, with an increase in ichnodiversity and ichnodisparity. Innovations in macrobioerosion clearly lagged behind animal-substrate interactions in unconsolidated sediment. The underlying causes of this evolutionary decoupling are unclear but may have involved three interrelated factors: (i) a Middle to Late Ordovician increase in available hard substrates for bioerosion, (ii) increased predation, and (iii) higher energetic requirements for bioerosion compared with bioturbation. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Puzzling rocks and complicated clocks: how to optimize molecular dating approaches in historical phytogeography" by Q Wang, and K.-S. Mao in a 2016 issue.

[Display omitted] • A new species-level phylogenetic hypothesis and time-tree of the Malagasy Scincinae are provided. • Diversification rate was constant until a sharp decrease around 6–4 million years ago. • Body size evolved homogenously across sub-clades and did not influence diversification rate. • Fossorial lifestyle evolved five independent times from quadrupedal ancestors and did not influence diversification rate. • Fossorial sand-swimmer genera likely diverged following an aridification of the Malagasy climate around 20 million years ago. Most of the unique and diverse vertebrate fauna that inhabits Madagascar derives from in situ diversification from colonisers that reached this continental island through overseas dispersal. The endemic Malagasy Scincinae lizards are amongst the most species-rich squamate groups on the island. They colonised all bioclimatic zones and display many ecomorphological adaptations to a fossorial (burrowing) lifestyle. Here we propose a new phylogenetic hypothesis for their diversification based on the largest taxon sampling so far compiled for this group. We estimated divergence times and investigated several aspects of their diversification (diversification rate, body size and fossorial lifestyle evolution, and biogeography). We found that diversification rate was constant throughout most of the evolutionary history of the group, but decreased over the last 6–4 million years and independently from body size and fossorial lifestyle evolution. Fossoriality has evolved from fully quadrupedal ancestors at least five times independently, which demonstrates that even complex morphological syndromes – in this case involving traits such as limb regression, body elongation, modification of cephalic scalation, depigmentation, and eyes and ear-opening regression – can evolve repeatedly and independently given enough time and eco-evolutionary advantages. Initial diversification of the group likely occurred in forests, and the divergence of sand-swimmer genera around 20 Ma appears linked to a period of aridification. Our results show that the large phenotypic variability of Malagasy Scincinae has not influenced diversification rate and that their rich species diversity results from a constant accumulation of lineages through time. By compiling large geographic and trait-related datasets together with the computation of a new time tree for the group, our study contributes important insights on the diversification of Malagasy vertebrates. [ABSTRACT FROM AUTHOR]

Evolutionary radiations have intrigued biologists for more than 100 years, and our understanding of the patterns and processes associated with these radiations continues to grow and evolve. Recently it has been recognized that there are many different types of evolutionary radiation beyond the well-studied adaptive radiations. We focus here on multifarious types of evolutionary radiations, paying special attention to the abiotic factors that might trigger diversification in clades. We integrate concepts such as exaptation, species selection, coevolution, and the turnover-pulse hypothesis (TPH) into the theoretical framework of evolutionary radiations. We also discuss other phenomena that are related to, but distinct from, evolutionary radiations that have relevance for evolutionary biology. [ABSTRACT FROM AUTHOR]

Tropical rainforest hyperdiversity is often suggested to have evolved over a long time-span (the 'museum' model), but there is also evidence for recent rainforest radiations. The mahoganies (Meliaceae) are a prominent plant group in lowland tropical rainforests world-wide but also occur in all other tropical ecosystems. We investigated whether rainforest diversity in Meliaceae has accumulated over a long time or has more recently evolved., We inferred the largest time-calibrated phylogeny for the family to date, reconstructed ancestral states for habitat and deciduousness, estimated diversification rates and modeled potential shifts in macro-evolutionary processes using a recently developed Bayesian method., The ancestral Meliaceae is reconstructed as a deciduous species that inhabited seasonal habitats. Rainforest clades have diversified from the Late Oligocene or Early Miocene onwards. Two contemporaneous Amazonian clades have converged on similar ecologies and high speciation rates., Most species-level diversity of Meliaceae in rainforest is recent. Other studies have found steady accumulation of lineages, but the large majority of plant species diversity in rainforests is recent, suggesting (episodic) species turnover. Rainforest hyperdiversity may best be explained by recent radiations from a large stock of higher level taxa. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including evolutionary plant radiations on island-like systems, an empirical evidence for the timing of vascular plants' diversification, and progressive radiations across angiosperms.

283I.283II.284III.284IV.287V.288288References288 Summary: Evolutionary divergence‐age estimates derived from molecular ‘clocks’ are frequently correlated with paleogeographic, paleoclimatic and extinction events. One prominent hypothesis based on molecular data states that the dominant pattern of Southern Hemisphere biogeography is post‐Gondwanan clade origins and subsequent dispersal across the oceans in a metaphoric ‘Green Web’. We tested this idea against well‐dated Patagonian fossils of 19 plant lineages, representing organisms that actually lived on Gondwana. Most of these occurrences are substantially older than their respective, often post‐Gondwanan molecular dates. The Green Web interpretation probably results from directional bias in molecular results. Gondwanan history remains fundamental to understanding Southern Hemisphere plant radiations, and we urge significantly greater caution when using molecular dating to interpret the biological impacts of geological events. [ABSTRACT FROM AUTHOR]

Although only a small fraction of the estimated 6000 extant bryozoan species has been analysed in a molecular phylogenetic context, the resultant trees have increased our understanding of the interrelationships between major bryozoan groups, as well as between bryozoans and other metazoan phyla. Molecular systematic analyses have failed to recover the Lophophorata as a monophyletic clade until recently, when phylogenomic data placed the Brachiopoda as sister to a clade formed by Phoronida + Bryozoa. Among bryozoans, class Phylactolaemata has been shown to be the sister group of Gymnolaemata + Stenolaemata, corroborating earlier anatomical inferences. Despite persistent claims, there are no unequivocal bryozoans of Cambrian age: the oldest bryozoans are stenolaemates from the Tremadocian of China. Stenolaemates underwent a major radiation during the Ordovician, but the relationships between the six orders involved are poorly understood, mostly because the simple and plastic skeletons of stenolaemates make phylogenetic analyses difficult. Bryozoans were hard-hit by the mass extinction/s in the late Permian and it was not until the Middle Jurassic that they began to rediversify, initially through the cyclostome stenolaemates. The most successful post- Palaeozoic order ( Cheilostomata) evolved a calcareous skeleton de novo from a soft-bodied ancestor in the Late Jurassic, maintained a low diversity until the mid- Cretaceous and then began to radiate explosively. A remarkable range of morphological structures in the form of highly modified zooidal polymorphs, or non-zooidal or intrazooidal modular elements, is postulated to have evolved repeatedly in this group. Crucially, many of these structures have been linked to micropredator protection and can be interpreted as key traits linked to the diversification of cheilostomes. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibetan Plateau (QTP) is the highest and one of the most extensive plateaus in the world. Phylogenetic, phylogeographic and ecological studies support plant diversifications on the QTP through multiple mechanisms such as allopatric speciation via geographic isolation, climatic oscillations and divergences, pollinator-mediated isolation, diploid hybridization and introgression, and allopolyploidy. These mechanisms have driven spectacular radiations and/or species diversifications in various groups of plants such as Pedicularis L., Saussurea DC., Rhododendron L., Primula L., Meconopsis Vig., Rhodiola L., and many lineages of gymnosperms. Nevertheless, much work is needed toward understanding the evolutionary mechanisms of plant diversifications on the QTP. Well-sampled biogeographic analyses of the QTP plants in the broad framework of the Northern Hemisphere as well as the Southern Hemisphere are still relatively few and should be encouraged in the next decade. This paper reviews recent evidence from phylogenetic and biogeographic studies in plants, in the context of rapid radiations, mechanisms of species diversifications on the QTP, and the biogeographic significance of the QTP in the broader context of both the Northern and Southern Hemisphere biogeography. Integrative multidimensional analyses of phylogeny, morphological innovations, geography, ecology, development, species interactions and diversifications, and geology are needed and should shed insights into the patterns of evolutionary assembly and radiations in this fascinating region.

Mammalian phylogeny is far too asymmetric for all contemporaneous lineages to have had equal chances of diversifying. We consider this asymmetry or imbalance from four perspectives. First, we infer a minimal set of 'regime changes'-points at which net diversification rate has changed- identifying 15 significant radiations and 12 clades that may be 'downshifts'. We next show that mammalian phylogeny is similar in shape to a large set of published phylogenies of other vertebrate, arthropod and plant groups, suggesting that many clades may diversify under a largely shared set of 'rules'. Third, we simulate six simple macroevolutionary models, showing that those where speciation slows down as geographical or niche space is filled, produce more realistic phylogenies than do models involving key innovations. Lastly, an analysis of the spatial scaling of imbalance shows that the phylogeny of species within an assemblage, ecoregion or larger area always tends to be more unbalanced than expected from the phylogeny of species at the next more inclusive spatial scale. We conclude with a verbal model of mammalian macroevolution, which emphasizes the importance to diversification of accessing new regions of geographical or niche space. [ABSTRACT FROM AUTHOR]

Evolutionary radiations, times of profound diversification of species against a broader background of more muted evolutionary change, have long been considered one of the fundamental patterns in the fossil record. Further, given the important role geological, environmental, and climatic processes play in causing speciation, analyzing the biogeographic context of radiations can yield important insight into their evolutionary mechanisms. In this study we examine biogeographic patterns and quantify rates of speciation in a diverse group of Devonian trilobites, the calmoniids, that has been hailed as a classic paleontological example of an evolutionary radiation. In particular, a phylogenetic biogeographic analysis—modified Brooks Parsimony Analysis—was used to examine the processes and geographic setting of speciation within the group. Results indicate that the Malvinokaffric Realm was a geographically complex area, and this geographic complexity created various opportunities for speciation via geodispersal and vicariance that created the fuel that fed the speciation in these taxa. Part of the geographic complexity was created not only by the inherent geologic backdrop of the region, but the overlying changes of sea level rise and fall. Rates of speciation were highest when sea level was lowest. Low sea level encouraged isolation of faunas in different tectonic basins. By contrast, sea level rise facilitated range expansion and geodispersal to other distinct tectonic basins, and speciation rates concomitantly fell; however, the taxa with the expanded ranges were later fodder for diversification when sea level fell again. Here we present a view of evolutionary radiations driven fundamentally by external abiotic factors—geology and climate—that cause range expansion and opportunities for geographic isolation with resultant rapid speciation. [ABSTRACT FROM AUTHOR]

Taphrhelminthopsis was originally introduced for trace fossils with a bilobate lower surface recorded in post-Paleozoic deep-marine deposits but has more recently been reinterpreted convincingly as a preservational variant of Scolicia. However, Taphrhelminthopsis has also been used for Cambrian shallow-marine trace fossils, whose taxonomic affinity remains elusive. This practice was introduced with the erection of Taphrhelminthopsis circularis Crimes et al., 1977 , based on specimens from lower Cambrian strata of Asturias, Spain, that have a bilobate morphology with a median furrow and a tendency to form a roughly circular course. Taphrhelminthopsis circularis subsequently has been recorded in many lower Cambrian successions worldwide. No information on toponomy was provided in the original description, which has complicated the reevaluation of this ichnotaxon. Reanalysis of the type specimen and study of additional material at the type locality demonstrate that Taphrhelminthopsis circularis occurs on the tops of sandstone layers, with a convex-upward bilobate structure, representing a preservational and behavioral variant of Psammichnites, in agreement with earlier tentative proposals. The presence in some material of a sinuous axial furrow, which is regarded as diagnostic of Psammichnites gigas, argues for synonymization of Taphrhelminthopsis circularis with that ichnospecies. However, to underscore potentially significant preservational and behavioral variability, we refer to this form as Psammichnites gigas circularis. We also discuss the relationships between Psammichnites and other trace fossils commonly recorded from Cambrian shallow-marine strata under a wide variety of names, including Archaeonassa fossulata, Arcuatichnus wimani, Helminthoida crassa, Helminthoida miocenica, Multilaqueichnus ganluonensis, Multilaqueichnus meishucunensis, Nereites saltensis, Parapsammichnites pretzeliformis, Plagiogmus arcuatus, Sellaulichnus meishucunensis, Taphrhelminthoida dailyi, Taphrhelminthopsis nelsoni, and Taphrhelminthopsis minimus. We recommend reassigning Plagiogmus arcuatus to Psammichnites gigas arcuatus, acknowledging the distinctive "ladder-trail" ornament found on its lower surface but also its overall similarity to Psammichnites gigas, as recognized by previous workers. Additionally we recommend applying the designation Psammichnites gigas gigas to specimens of Psammichnites gigas characterized by high convexity, a straight to sinuous axial ridge or groove, and a straight, sinuous, or curved path, and lacking a "ladder-trail" ornament. Documenting the multiple preservational variants of Cambrian Psammichnites is important to estimate ichnodiversity levels accurately during the Cambrian explosion and to enhance the value of this ichnotaxon for stratigraphic correlation. [ABSTRACT FROM AUTHOR]

To introduce and describe the functioning of a new algorithm, phylogenetic analysis for comparing trees (PACT), for generating area cladograms that provide accurate representation of information contained in taxon–area cladograms.PACT operates in the following steps. Convert all phylogenies to taxon–area cladograms. Convert all taxon–area cladograms to Venn diagrams. Choose any taxon–area cladogram from the set of taxon–area cladograms to be analysed and determine its elements. This will be the template area cladogram. Select a second taxon–area cladogram. Determine its elements. Document which elements in the second tree occur in the template tree (denoted by‘Y’) and which do not (denoted by‘N’). Each‘Y’ indicates a match with previous pattern and these are combined. Each‘N’ is a new element and is attached to the template area cladogram at the node where it is linked with a Y. This requires two rules: (1)‘Y + Y = Y’ (combine common elements) as long as they are connected at the same node; and (2)‘Y + N = YN’ (add novel elements to the template area cladogram at the node where they first appear). Once the novel elements in the second taxon–area cladogram have been added to the template area cladogram, see if any of them can be further combined. This requires three additional rules: (1)‘Y(Y− = Y(Y−’ (do not combine Y's if they are attached at different nodes on the template area cladogram); (2)‘Y + YN = YN’ (Y is part of group YN); and (3)‘YN + YN = YNN’ (Y is the same for each, but each N is different). Repeat for all available taxon–area cladograms.Three exemplars demonstrate that PACT provides the most accurate area cladograms for vicariance-driven biotic diversification, dispersal-driven biotic diversification and taxon pulse-driven biotic diversification. PACT can also be used as ana priorimethod of biogeographical analysis.PACT embodies all the strong points and none of the weaknesses of previously proposed methods of historical biogeography. It is most useful as ana posteriorimethod, but it is also superior to all previousa priorimethods because it does not specify costs, or weights or probabilities, or likelihoods of particular biogeographical processesa prioriand is thus sensitive to clade-specific historical contingencies. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various topics within the issue including broad spectrum of plant science, the evolutionary ecology of ant-plant symbioses and evolution of mycorrhiza.