Large Vertebrates Research Articles

No evidence for trade-offs in plant responses to consumer food web manipulations.

Plants face a range of trade-offs as they attempt to maximize their fitness within a complex web composed of competitors, mutualists, and herbivores. In addition to growth-defense and competition-defense trade-offs, plants must balance their response to a wide range of potential enemies including pathogens and vertebrate and invertebrate herbivores. We tested for trade-offs in plant species' responses to different types of consumers using a foodweb manipulation experiment in which we selectively excluded large vertebrate herbivores and removed foliar fungi, soil fungi, and insects from natural and experimentally planted grassland communities. We found no evidence for trade-offs in the ability of plants to defend themselves against different sets of consumers, although plants varied widely in their responses to removal of different consumer groups. In addition, the species-level responses to consumer removal in monoculture were uncorrelated with each species' response in more diverse communities, highlighting the important role of local context (e.g., competition and apparent competition) in determining the effects of consumers. Plants must balance their allocation of energy among a wide variety of tasks including growing, competing for limited resources, and defending themselves against an array of potential enemies. We found that while plant species differed greatly in their response to the removal of consumers, species that were susceptible to the effects of one consumer group (e.g., insect herbivores) also were susceptible to other consumer groups (e.g., fungal pathogens). This suggests that plants differ in their overall allocation to defense, but defense investment can proffer protection against a wide array of natural enemies. We also found that plant responses to consumers depended on the diversity of the surrounding plant community, suggesting that among-plant interactions can alter their susceptibility to the impacts of consumers.

Seasonal dynamics of terrestrial vertebrate abundance between Amazonian flooded and unflooded forests.

The flood pulse is the main factor structuring and differentiating the ecological communities of Amazonian unflooded (terra firme) and seasonally-flooded (várzea) forests as they require unique adaptations to survive the prolonged annual floods. Therefore, várzea and terra firme forests hammer out a spatio-temporal mosaic of resource availability, which may result in landscape scale seasonal movements of terrestrial vertebrates between adjacent forest types. Yet the lateral movements of terrestrial vertebrates between hydrologically distinct neighbouring forest types exhibiting staggered resource availability remains poorly understood, despite the important implications of this spatial dynamic for the ecology and conservation of forest wildlife. We examined the hypothesis of terrestrial fauna seasonal movements between two adjacent forest types at two contiguous sustainable-use forest reserves in Western Brazilian Amazonia. We used camera trapping data on the overall species richness, composition, and abundance of nine major vertebrate trophic guilds to infer on terrestrial vertebrate movements as a function of seasonal changes in floodplain water level. Species richness differed in neighboring terra firme forests between the high-and low-water phases of the flood pulse and terra firme forests were more species rich than várzea forests. There were clear differences in species composition between both forest types and seasons. Generalized Linear Models showed that water level was the main factor explaining aggregate abundance of all species and three trophic guilds. Our results indicate that the persistence of viable populations of large terrestrial vertebrates adjacent to major Amazonian rivers requires large, well-connected forest landscapes encompassing different forest types to ensure large-scale lateral movements by forest wildlife.

Persistence of ground-dwelling invertebrates in desert grasslands during a period of low rainfall – Part 2

Current knowledge on the life history of Australia's arid zone invertebrates is sparse. From the studies conducted in arid zones globally, the primary drivers of invertebrates are thought to be climate, particularly temperature and rainfall. In Australia, a limited number of studies have shown vegetation and inter-species interactions are also highly influential. We investigated the effects of multiple potential drivers on ground-dwelling invertebrates in the spinifex sand plains of central Australia. The study was conducted during a period of low rainfall immediately following several years of higher than average rainfall. Results supported the trends found globally, with rainfall and temperature the most consistent drivers. Vegetation cover was not found to be an important driver; however increased abundance of large vertebrate predators coincided with greater abundance of many invertebrate orders. Areas supporting greater invertebrate abundances likely attract predators, particularly during periods when resources are low, and potentially play an important role in sustaining their populations during these periods. No suppressive effects were found, indicating many invertebrates can withstand the higher predator pressure apparent during low rainfall periods. This study highlights the important roles invertebrates play in ecosystem functioning and a need to gain a greater understanding of this little known group.

Efficient Digitisation of Unaccessioned Specimens in a Large Vertebrate Fossil Collection to Enhance Data Quality and Mitigate Risk

The Museums Victoria (NMV) Vertebrate Palaeontology Collection holds more than 130,000 specimens, including the single largest collection of vertebrate fossils from the state of Victoria, Australia. Accessioned specimens make up around one third of the collection; however, few of the other, unaccessioned specimens have been catalogued. Vertebrate fossil accession at NMV is carried out in three stages: registration under a permanent specimen number, entry into the database software catalogue Axiell EMu, and barcode-based location tracking using a handheld device linked to an online application (http://mvwise.museum.vic.gov.au). In the past, unregistered specimens have been catalogued or location- tracked only infrequently, and the scale of legacy subcollections makes full registration an impractical goal for unaccessioned specimens. Accurate knowledge of unaccessioned specimens is essential to estimate collection size and composition, and predict future resource needs. Where such knowledge is held by staff but not documented, there is a persistent risk of dissociation or loss. Further, having accessible digital records greatly enhances data discoverability for research and exhibition users. We describe an EMu-based workflow for unaccessioned specimens in the NMV Vertebrate Palaeontology Collection, which newly documents and tracks specimens without the time burden of prior accession protocols. Minimum-data EMu catalogue records are generated from a handheld MVWISE scanner (based on Apple mobile hardware), with photographs that include the specimen along with any existing metadata or context. These records are immediately linked to trackable barcodes associated with storage locations. Subsequently, relevant taxonomic, stratigraphic or historical information can be cross-referenced to catalogue records en masse, either directly or using import functions. This metadata is accessed efficiently from within Axiell EMu via the specimen photographs, rather than requiring a subsequent physical search. The risks mitigable by this project are discussed, as are reasons commonly cited for not accessioning specimens, and dilemmas and consequences arising from the new approach. We also provide guidance on the rates of data generation, the required and recommended resources to be used, and forecast practical benefits in discovery and use for the collection.

Proactive conservation and restoration of botanical diversity in the Anthropocene's “rambunctious garden”

Proactive conservation and restoration of botanical diversity in the Anthropocene's “rambunctious garden”

When predators become prey: Community-based monitoring of caiman and dolphin hunting for the catfish fishery and the broader implications on Amazonian human-natural systems

Wildlife hunting for commercial products has been responsible for decline of many large vertebrates around the globe. An Amazonian example of this worldwide trend is the use of caiman and dolphins as bait for the piracatinga catfish fishery. While it is a controversial issue in Amazonia conservation, there is no data on key biological aspects, such as age and sex, of those animals illegally hunted for bait. This lack of data complicates understanding of the true impact of bait-hunting on the targeted species. In this study, we present results of one year of participatory monitoring of bait-hunting in 12 communities in the Mamirauá Sustainable Development Reserve (MSDR), Brazilian Amazonia, during which participants recorded aspects of hunting activity and biometric data of animals used as piracatinga bait. The piracatinga fishery at MSDR has distinct spatial and seasonal patterns, being concentrated close to distribution centers and intensifying during the dry season. Adult male black caiman is the main bait used by fishermen, but viscera of commercial fish provide a potential alternative bait source for the piracatinga fishery. All recorded bait hunting was for caiman, none for dolphins. Despite the predominant use of caiman as bait, MSDR caiman populations remain the largest within the species' distribution. We suggest that informal management of caiman conducted by MSDR residents has guaranteed regional sustainability of the piracatinga fishery. In a broader context, the current study highlights the potential for participatory research with local populations in formulating well-informed decisions for the conservation of natural resources and economic alternatives focused on the conservation of human-natural systems.

Late Cretaceous climate in the Canadian Arctic: Multi-proxy constraints from Devon Island

Arctic climate in the Late Cretaceous has long been recognized to have been warm and wet relative to the present, but quantitative assessments of paleoclimate have been challenging due, in part, to disagreements between proxies in marine and terrestrial environments. This study provides a first multiproxy evaluation of Late Cretaceous (~93–90 Ma to 73–72 Ma) paleoclimate and paleohydrology from Devon Island in the Canadian High Arctic (modern location: 76°17′N, 91°12′W; Late Cretaceous location: ~71°30′N, ~24°30′W). Surface temperatures are reconstructed at ~12.6 to 20.6 °C for the ocean and 11.7 to 16.9 °C over land, using glycerol dialkyl glycerol tetraether (GDGT) based proxies measured from marine (TEX86) and terrestrial samples (MBT′5ME). These proxies are likely skewed toward warm month temperatures, based on novel analysis and interpretation of biomarkers in sediment and co-occurring marine vertebrate coprolites. The hydrogen isotopic composition (δ2H) of precipitation is constrained to have varied from −123‰ to −82‰ (VSMOW) using evidence from n-alkanes likely derived from higher plants. δ18O of shelfal marine surface water is constrained to have been between −10.5‰ to −3.4‰, using phosphate oxygen isotopes of marine vertebrate teeth and coprolites. From these, marine salinity is modeled to have varied from 10 PSU and 30 PSU, indicative of periodic freshwater influx. These estimates indicate that large marine vertebrates lived and fed, at least intermittently, in near-shore brackish waters. Finally, the Arctic was similarly warm in both the Late Cretaceous and Paleocene/Eocene, but the Late Cretaceous isotopic composition of precipitation at Devon Island was enriched in the heavy isotope of hydrogen by up to +60 to +70‰ relative to Arctic Eocene sites. The combination of techniques used here reduces uncertainties related to the application of proxies to an environment without a modern analogue, providing novel paleoclimatic constraints on the Late Cretaceous Arctic region.

Armed conflicts and wildlife decline: Challenges and recommendations for effective conservation policy in the Sahara‐Sahel

AbstractIncreasing conflicts and social insecurity are expected to accelerate biodiversity decline and escalate illegal wildlife killing. Sahara‐Sahel megafauna has experienced recent continuous decline due to unsustainable hunting pressure. Here, we provide the best available data on distribution and population trends of threatened, large vertebrates, to illustrate how escalating regional conflict (565% growth since 2011) is hastening population decline in areas that were formerly refugia for megafauna. Without conservation action, the unique and iconic biodiversity of Earth's largest desert will be forever lost. We recommend: (1) establishing strong commitments for change in global attitude toward nature; (2) engraining a culture of environmental responsibility among all stakeholders; (3) fostering environmental awareness to drive societal change; (4) reinforcing regional security and firearms control; and (5) implementing local research and wildlife monitoring schemes. We identify relevant international partners needed to tackle these challenges and to make strong policy change for biodiversity conservation and regional stability.

Analysis of occurrence patterns and biological factors of cetaceans based on long‐term and fine‐scale data from platforms of opportunity: Madeira Island as a case study

AbstractManagement and conservation issues are addressed through the identification of areas of particular importance, which requires the acquisition of baseline information on species distribution and dynamics. These types of data are particularly difficult to obtain at high resolution for large marine vertebrates like cetaceans, given that dedicated surveys are complex and logistically expensive. This study uses daily presence–absence sighting data of cetaceans collected year‐round from whale‐watching boats to support the theory that fine‐scale data obtained from platforms of opportunity can provide valuable information on species occurrence and group dynamics. Data from 7,551 (daily) sightings comprising 22 species were collected from 3,527 surveyed days over 11 years (mean of 321 days per year, SD = 17) in the pelagic environment of Madeira Island. Cetaceans were observed on 92% of the surveyed days, and a mean of 15.4 (SD = 1.5), 8.2 (SD = 2.0) and 2.1 (SD = 1.2) species were recorded per year, month, and day, respectively. There were significant differences in the number of species per month (p < .001), with the highest diversity recorded in June. At least nine species, comprising 96% of all sightings, were found to use the Madeiran waters on a regular basis, such as the Atlantic spotted dolphin (Stenella frontalis), the short‐beaked common dolphin (Delphinus delphis), the bottlenose dolphin (Tursiops truncatus), and others featured in the Red List of the International Union for Conservation of Nature as Endangered, Vulnerable, and Data Deficient. In addition, 10 species were found to use the Madeiran waters for travelling, feeding, resting, socializing and calving, which suggests that the southern and southeastern waters of Madeira Island constitute an area of interest for cetaceans. This study characterizes the cetaceans’ community structure (occurrence, aggregation sizes, behaviours, proportion of calves, and inter‐specific relationships) of a poorly studied region, providing important information for managers. Finally, the advantages and limitations of using fine‐scale data from a type of platform of opportunity that is increasing along coastlines globally are discussed.

Road Mortality of Vertebrates Along Two-Lane Highway in Southcentral Kansas: Historical Data from the 1980's

Road kills impact many wildlife species, but only a limited number of studies have included small animals during these surveys. This study described the road mortality for large, medium and small vertebrates, which includes amphibians, reptiles, small mammals and birds. A 32.2 km stretch of Kansas Highway K254 was surveyed from 31 May 1985 thru 20 May 1987. Eighty-eight species comprised the 4484 individuals found during this study. The road mortality for mammal and bird groups here resembled those reported in other studies, but differed from those reported for herpetofauna group. Ornate box turtle, prairie kingsnake and gopher snake sustained higher road mortalities than found in previous studies. Wildlife also experienced greater road mortality in a landscape where prairie occurred in large contiguous tracts compared with a patchwork of small stands. This study showed that surveying a limited stretch of highway represents a feasible way to obtain accurate road mortality data.

Evidence for nonconsumptive effects from a large predator in an ungulate prey?

Predators can indirectly affect prey survival and reproduction by evoking costly antipredator responses. Such nonconsumptive effects may be as strong or stronger than consumptive predator effects. However, evidence for this in large terrestrial vertebrate systems is equivocal and few studies quantify the actual fitness costs of nonconsumptive effects. Here, we investigated whether nonconsumptive effects elicited by Eurasian lynx (Lynx lynx), a large terrestrial predator, reduced survival in an ungulate prey, the European roe deer (Capreolus capreolus). To reveal the behavioral processes underlying nonconsumptive effects, we distinguished between proactive risk avoidance of areas with high lynx encounter probability, and reactive risk avoidance in response to actual lynx encounters and analyzed these responses using step selection functions. We also quantified the consequences of these behaviors for deer survival. Deer reacted differently at day and at night, but avoided high-risk areas proactively during the day and at night in the summer. During a predator encounter, deer increased avoidance of high-risk areas at night but not during the day. Thus, roe deer exhibited a behavioral response race that involved temporally and spatially varying tradeoffs with environmental constraints. We found evidence that nonconsumptive effects of lynx predation risk reduced deer survival and that survival was more sensitive to variation in nonconsumptive effects of lynx than to variation in human proximity. Our findings highlight that nonconsumptive effects may depend on the spatiotemporal distribution of risks and the environmental context, and we discuss how human factors contribute to predator–prey dynamics in human dominated landscapes.

African carnivores as taphonomic agents: Contribution of modern coprogenic sample analysis to their identification

AbstractIn archaeological sites, large, medium, and small vertebrate remains may have been accumulated by humans, by nonhuman predators, or both. It is now assumed that neotaphonomic referentials are essential to contribute to characterising the accumulators of fossil assemblages. However, such reference data are lacking for many areas (such as North Africa) and for several predators. In addition, most of the existing studies focus on skeleton representation, bone fragmentation, and tooth marks on noningested remains. Faeces‐containing ingested remains are still rarely considered, especially for viverrids, small or medium canids, or large felids. This paper provides new taphonomic data concerning the ingested remains of diversified prey (herbivores, lagomorphs, rodents, amphibians, fish, squamates, birds, and insects) from coprogenic samples accumulated by these predators. As expected, small or medium‐small carnivores consumed more small vertebrates than did medium‐large and large carnivores. Among the small vertebrate remains from small and medium‐small carnivore scats, limb extremities are less represented than other parts of the skeleton, whereas in meso‐macromammal remains from medium‐large and large carnivore scats, small bones (from limb extremities) are abundant. Digestion attack seems to be more developed on small vertebrate remains from small and medium‐small carnivore scats than in mesofaunal prey remains from medium‐large and large carnivore scats. Among small and medium‐small carnivores, prey from cf. fox scats (mainly microvertebrates) are more diversified, more fragmented, and more digested than in small carnivore (cf. genet) samples. Among medium‐large and large carnivores, fragmentation and digestion attack on mesofaunal remains are more intense in large carnivore (cf. leopard) scats than in medium‐large (cf. jackal/wolf) scats. Finally, in order to improve characterisation of the predator responsible for fossil faunal accumulations, we highlight here the importance of considering all the small bone fragments from sieve residues in archaeological contexts (and not only whole bones and identified bone fragments).

Eggs for breakfast? Analysis of a probable mosasaur biting trace on the Cretaceous echinoid <i>Echinocorys ovata</i> Leske, 1778

Abstract. Fossil biting traces (praedichnia) represent indirect evidence of predation and shed light on fossil predator–prey interactions and fossil food webs. Especially from echinoderm skeletons, biting traces are well known. Here, we describe the oral surface of a large Cretaceous (Maastrichtian) holasteroid echinoid Echinocorys ovata Leske, 1778 from Hemmoor (northern Germany) which exhibits four circular punctures arranged in a semi-circular arc. Whereas three of the punctures penetrated the skeleton, one puncture only just hit the margin of the echinoid test at the ambitus, leaving a long incision furrow in the skeleton. The punctures were not lethal to the sea urchin as is indicated by progressed skeletal regeneration and closure of the fractures. The overall appearance of the punctures suggests that they were produced during a single mechanical event, most likely by the biting action of the teeth of a large vertebrate animal. We analysed the shape and arrangement of the biting trace and conclude that it was probably produced by a marine reptile possessing a prognath tooth position, most likely by a globidensine mosasauroid. Our finding not only sheds light on mosasaur feeding behaviour and prey selection but also increases the knowledge of the food webs in the chalk sea ecosystem during the uppermost Cretaceous.

Convergence of marine megafauna movement patterns in coastal and open oceans

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.

Diverse papillomaviruses identified in Weddell seals.

Papillomaviridae is a diverse family of circular, double-stranded DNA (dsDNA) viruses that infect a broad range of mammalian, avian and fish hosts. While papillomaviruses have been characterized most extensively in humans, the study of non-human papillomaviruses has contributed greatly to our understanding of their pathogenicity and evolution. Using high-throughput sequencing approaches, we identified 7 novel papillomaviruses from vaginal swabs collected from 81 adult female Weddell seals (Leptonychotes weddellii) in the Ross Sea of Antarctica between 2014-2017. These seven papillomavirus genomes were amplified from seven individual seals, and six of the seven genomes represented novel species with distinct evolutionary lineages. This highlights the diversity of papillomaviruses among the relatively small number of Weddell seal samples tested. Viruses associated with large vertebrates are poorly studied in Antarctica, and this study adds information about papillomaviruses associated with Weddell seals and contributes to our understanding of the evolutionary history of papillomaviruses.

Defaunation increases the spatial clustering of lowland Western Amazonian tree communities

Abstract Declines of large vertebrates in tropical forests may reduce dispersal of tree species that rely on them, and the resulting undispersed seedlings might suffer increased distance‐ and density‐dependent mortality. Consequently, extirpation of large vertebrates may alter the composition and spatial structure of plant communities and impair ecosystem functions like carbon storage. We analysed spatial patterns of tree recruitment within six forest plots along a defaunation gradient in western Amazonia. We divided recruits into two size cohorts (“saplings”: ≥1 m tall and <1 cm diameter at breast height [dbh], and juveniles, 1–2 cm dbh) and examined the spatial organisation of conspecific recruits within each cohort (within‐cohort) and around conspecific reproductive‐sized trees (between‐cohort). We used replicated spatial point pattern analysis to quantify relationships between recruit clustering and cohort, defaunation intensity, each tree species reliance on hunted dispersers and the interactions among these three covariates. Within‐cohort clustering of conspecific saplings increased with reliance of tree species on hunted dispersers, and this trend strengthened significantly as defaunation increased, probably because of reduced dispersal. Within‐cohort clustering of conspecifics declined from saplings to juveniles, suggesting density‐dependent mortality of saplings. However, the positive relationship between sapling clustering and defaunation did not lead to greater reductions in within‐cohort clustering during the sapling–juvenile transition, suggesting that higher conspecific densities did not translate into increased mortality. Instead, the increased spatial clustering associated with defaunation was retained for juvenile recruits. Between‐cohort clustering was unrelated to defaunation and did not change during the sapling–juvenile transition. Synthesis. Defaunation increased spatial aggregation of saplings of tree species reliant on hunted dispersers. The increase in sapling clustering did not increase density‐dependent thinning, and persisted into older recruit cohorts, suggesting that hunting may initiate long‐term spatial reorganisation of Amazonian tree communities. The lack of increased density‐dependent thinning indicates that reduced dispersal did not increase mortality of large‐vertebrate dispersed tree species that contribute disproportionately to forest biomass. We, therefore, caution against the fait accompli acceptance of the prediction by recent modelling studies that overhunting will precipitate a collapse in carbon sequestration by tropical forests.

Ungulate dietary adaptations and palaeoecology of the Middle Pleistocene site of Fontana Ranuccio (Anagni, Central Italy)

The Middle Pleistocene site of Fontana Ranuccio (Anagni Basin, Central Italy) has yielded nearly 25,000 remains belonging to large and small vertebrates, including four isolated teeth of Homo sp., and a rich lithic assemblage containing bone tools. Here we provide new dental wear analyses of the ungulate community to improve the palaeoenvironmental reconstruction for the site. Analyses indicate a mostly browsing diet for the cervids and a grazing diet for the perissodactyls Stephanorhinus sp. and Equus cf. E. mosbachensis, suggesting a range of habitats that spanned from forests to open grasslands. A discrepancy between mesowear and microwear results is observed in the case of the bovid, Bos primigenius; this can be tentatively explained as resulting from a temporal switch towards a sub-optimal diet, possibly reflecting the effects of marked seasonality. Findings shed new light on the structure of the 400 kyr ecosystems that existed during the early occupation of Homo in Europe.

A test of the predator satiation hypothesis, acorn predator size, and acorn preference

Mast seeding is hypothesized to satiate seed predators with heavy production and reduce populations with crop failure, thereby increasing seed survival. Preference for red or white oak acorns could influence recruitment among oak species. We tested the predator satiation hypothesis, acorn preference, and predator size by concurrently measuring acorn production, mouse abundance, and white versus red oak acorn removal rates in exclosures allowing access by mice (HW), squirrels and smaller-sized vertebrates (WW), or all-sized vertebrates (C) for 12 years. Annual removal rate varied, but virtually all acorns were eventually removed from all exclosure types all years except one. Acorns were removed more slowly from HW than from WW or C exclosures, indicating that large vertebrates were not major acorn consumers, locally. Red and white oak acorn removal rates were similar except in two years, when red oak acorns were removed more rapidly. Removal slowed with increasing acorn crops, suggesting that heavy crops can “swamp” predators. Removal rate was negatively correlated with crop size the previous fall. A positive trend between mouse abundance and crop size the previous fall was evident; abundance decreased sharply the year following crop failures but not after moderate or heavy crops, suggesting that poor crops can dampen acorn predation the following year.

Palaeoecology before ecology: the rise of actualism, palaeoenvironmentes studies and palaeoclimatology in the Italian panorama between the fourteenth and eighteenth centuries

The systematic use of fossil and sedimentological characters in palaeoenvironmental, palaeoecological and palaeoclimatic reconstructions is a fairly recent breakthrough of Earth Sciences. Traditionally, the works by James Hutton and Charles Lyell are viewed as true milestones of geology and the first coherent reasoning in the palaeoecologic context, as a necessary result of the new 'doctrine' of actualism. However, the foundation for actualistic reasoning, and their genuine use to interpret the fossil deposits, are clearly found in the writings of Italian naturalists more than four centuries before the publication of The Principles. In this paper, the first seeds of actualistic and palaeoecological reasoning, detectable in the Italian panorama between the thirteenth and early nineteenth century, are discussed. As early as the thirteenth century, authors like Ristoro d'Arezzo used sedimentary processes currently observed to interpret the fossil deposits. Naturalists as Marsili and Donati emphasized the close correspondence between the current seabed, abundance and distribution of species, and the conditions observed in the fossil deposits. Targioni Tozzetti surprises correctly interpreting the remains of large vertebrates in Italy as belonging to animals endemic of the Peninsula, using this evidence to infer a warmer climate in the past and surprising readers of the day with the modernity of his ideas. These great naturalists not only imagined a completely different flora based on the fossil record, but attributed the warmer climate of the past to changes in the sea level, thus providing arguments used by Lyell some eighty years later to explain climate change over geological time.

Global priorities for conserving the evolutionary history of sharks, rays and chimaeras.

In an era of accelerated biodiversity loss and limited conservation resources, systematic prioritization of species and places is essential. In terrestrial vertebrates, evolutionary distinctness has been used to identify species and locations that embody the greatest share of evolutionary history. We estimate evolutionary distinctness for a large marine vertebrate radiation on a dated taxon-complete tree for all 1,192 chondrichthyan fishes (sharks, rays and chimaeras) by augmenting a new 610-species molecular phylogeny using taxonomic constraints. Chondrichthyans are by far the most evolutionarily distinct of all major radiations of jawed vertebrates-the average species embodies 26 million years of unique evolutionary history. With this metric, we identify 21 countries with the highest richness, endemism and evolutionary distinctness of threatened species as targets for conservation prioritization. On average, threatened chondrichthyans are more evolutionarily distinct-further motivating improved conservation, fisheries management and trade regulation to avoid significant pruning of the chondrichthyan tree of life.