Vertebrate Extinctions Research Articles

Convergent evolution toward a slow pace of life predisposes insular endotherms to anthropogenic extinctions.

Island vertebrates have evolved a number of morphological, physiological, and life history characteristics that set them apart from their mainland relatives. However, to date, the evolution of metabolism and its impact on the vulnerability to extinction of insular vertebrates remains poorly understood. This study used metabolic data from 2813 species of tetrapod vertebrates, including 695 ectothermic and 2118 endothermic species, to reveal that island mammals and birds evolved convergent metabolic strategies toward a slow pace of life. Insularity was associated with shifts toward slower metabolic rates and greater generation lengths in endotherms, while insularity just drove the evolution of longer generation lengths in ectotherms. Notably, a slow pace of life has exacerbated the extinction of insular endemic species in the face of anthropogenic threats. These findings have important implications for understanding physiological adaptations associated with the island syndrome and formulating conservation strategies across taxonomic groups with different metabolic modes.

Undiscovered bird extinctions obscure the true magnitude of human-driven extinction waves

Birds are among the best-studied animal groups, but their prehistoric diversity is poorly known due to low fossilization potential. Hence, while many human-driven bird extinctions (i.e., extinctions caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as land use change, fire, and the introduction of invasive species) have been recorded, the true number is likely much larger. Here, by combining recorded extinctions with model estimates based on the completeness of the fossil record, we suggest that at least ~1300–1500 bird species (~12% of the total) have gone extinct since the Late Pleistocene, with 55% of these extinctions undiscovered (not yet discovered or left no trace). We estimate that the Pacific accounts for 61% of total bird extinctions. Bird extinction rate varied through time with an intense episode ~1300 CE, which likely represents the largest human-driven vertebrate extinction wave ever, and a rate 80 (60–95) times the background extinction rate. Thus, humans have already driven more than one in nine bird species to extinction, with likely severe, and potentially irreversible, ecological and evolutionary consequences.

Multiple co‐occurring bioeconomic drivers of overexploitation can accelerate rare species extinction risk

AbstractThe unsustainable harvest of species for the global wildlife trade is a major cause of vertebrate extinction. Through the anthropogenic Allee effect (AAE), overexploitation to extinction can occur when a species' rarity drives up its market price, enabling profitable harvest of all remaining individuals. Even in the absence of rarity value, however, the harvest of other species can subsidize the overexploitation of a rare species to the point of extinction, a phenomenon termed opportunistic exploitation. These two pathways to extinction have been considered independently, but many traded species experience them simultaneously.In this study, we develop a simple model that incorporates these mechanisms simultaneously and demonstrate that including multiple harvest strategies with market‐based feedbacks fundamentally alters rare species extinction risk and the rate at which overexploitation occurs. As a pertinent case study, we consider the harvest of ground pangolinsSmutsia temminckii.Our results show that pangolin extinction was generally associated with high rarity value, the use of multiple harvest strategies and the simultaneous harvest of a common species that has a fast life history. Pangolin population depletion and short‐term extinction risk were greatest when harvesters used a combination of pursuit and opportunistic (i.e. multi‐species) harvest strategies.Policy implications.Our results suggest that feedbacks between multiple financial incentives to overharvest can exacerbate the risk of extinction of rare species. As a result, continuing to address AAE and opportunistic exploitation as separate extinction pathways may insufficiently capture extinction risk for many exploited species. Criteria for assessing extinction risk or harvest sustainability of exploited species should incorporate multiple drivers of harvest pressure, with an expanded focus on including species with high rarity value that are exploited in multi‐species harvest regimes.

Worldwide host associations of the tick genus Ixodes suggest relationships based on environmental sharing rather than on co-phylogenetic events

BackgroundThis study aims to capture how ticks of the genus Ixodes gained their hosts using network constructs. We propose two alternative hypotheses, namely, an ecological background (ticks and hosts sharing environmentally available conditions) and a phylogenetic one, in which both partners co-evolved, adapting to existing environmental conditions after the association took place.MethodsWe used network constructs linking all the known pairs of associations between each species and stage of ticks with families and orders of hosts. Faith’s phylogenetic diversity was used to evaluate the phylogenetic distance of the hosts of each species and changes occurring in the ontogenetic switch between consecutive stages of each species (or the extent of the changes in phylogenetic diversity of hosts for consecutive stages of the same species).ResultsWe report highly clustered associations among Ixodes ticks and hosts, supporting the influence of the ecological adaptation and coexistence, demonstrating a lack of strict tick-host coevolution in most cases, except for a few species. Keystone hosts do not exist in the relationships between Ixodes and vertebrates because of the high redundancy of the networks, further supporting an ecological relationship between both types of partners. The ontogenetic switch of hosts is high for species with enough data, which is another potential clue supporting the ecological hypothesis. Other results suggest that the networks displaying tick-host associations are different according to the biogeographical realms. Data for the Afrotropical region reveal a lack of extensive surveys, while results for the Australasian region are suggestive of a mass extinction of vertebrates. The Palearctic network is well developed, with many links demonstrating a highly modular set of relationships.ConclusionsWith the obvious exceptions of Ixodes species restricted to one or a few hosts, the results point to an ecological adaptation. Even results on species linked to groups of ticks (such as Ixodes uriae and the pelagic birds or the bat-tick species) are suggestive of a previous action of environmental forces.Graphical

Half-millennium evidence suggests that extinction debts of global vertebrates started in the Second Industrial Revolution

Extinction debt describes the time-lagged process of species extinction, which usually requires dozens to hundreds of years to be paid off. However, due to the lack of long-term habitat data, it is indeterminate how strong the signal of extinction debts is at the global scale and when the debts started. Here, by compiling the geographical distributions of 6120 reptiles, 6047 amphibians, and 4278 mammals and correlating them with annual forest cover data from 1500 to 1992, we show that the beginning of the Second Industrial Revolution (the mid-19th century) was the earliest signal of cumulative extinction debts for global forest-dwelling vertebrate groups. More importantly, the impact of global protected areas on mitigating accumulated vertebrate extinction debt is not as immediate as that of mitigating reduced forest cover but rather suffers from pronounced time-lag effects. As the disequilibrium of vertebrate richness and forested habitat is currently taking place, preventive actions should be taken to promote a well-balanced status among forest restoration, protected areas, and biodiversity conservation to slow the accumulating debts for global forest-dwelling vertebrates.

The loss of biodiversity in Madagascar is contemporaneous with major demographic events

Only 400km off the coast of East Africa, the island of Madagascar is one of the last large land masses to have been colonized by humans. While many questions surround the human occupation of Madagascar, recent studies raise the question of human impact on endemic biodiversity and landscape transformation. Previous genetic and linguistic analyses have shown that the Malagasy population has emerged from an admixture that happened during the last millennium, between Bantu-speaking African populations and Austronesian-speaking Asian populations. By studying the sharing of chromosome segments between individuals (IBD determination), local ancestry information, and simulated genetic data, we inferred that the Malagasy ancestral Asian population was isolated for more than 1,000 years with an effective size of just a few hundred individuals. This isolation ended around 1,000 years before present (BP) by admixture with a small African population. Around the admixture time, there was a rapid demographic expansion due to intrinsic population growth of the newly admixed population, which coincides with extensive changes in Madagascar's landscape and the extinction of all endemic large-bodied vertebrates. Therefore, our approach can provide new insights into past human demography and associated impacts on ecosystems.

Endemic rodents of Hispaniola: biogeography and extinction timing during the Holocene

Hispaniola is the second-largest island in the West Indies bioregion and along with Cuba is considered the cradle of Greater Antillean rodent evolution and diversification. While the fossil record in Hispaniola includes ten extinct species of late Quaternary rodents, only a single species, the Hispaniola hutia (Plagiodontia aedium), is extant on the island. Changes in climate and anthropogenic effects have been suggested as drivers for these extinctions, but there are few radiometric dates associated with these fossils which limits our understanding of the timing of rodent extinctions on Hispaniola relative to shifts in Holocene climate and major events in human settlement and colonization. We report nine new AMS radiocarbon dates for six endemic rodents of Hispaniola that, when coupled with previously reported dates, provide last occurrence records for eight of the ten extinct rodent species there. Results show that Hispaniola rodent extinction occurred in a series of episodes, with more than half (63.6%) surviving into the late Holocene (4200 cal BP to present), postdating the initial arrival of Ceramic Age Indigenous groups, with extinction likely only after European colonization. This pattern in Hispaniola is consistent with what recent studies have found on the timing of extinction of other terrestrial vertebrates in the West Indies. Results from analysis of stable isotopes of fossil bone suggest that the extinction of endemic rodents from Hispaniola largely also postdate habitat changes following the onset of drier conditions in the late Holocene, suggesting that while climate may have shaped the geographic distribution of species, it probably played a minimal direct role in their extinctions on Hispaniola.

Senescence and Differential Size-Based Survival in Puerto Rican Giant Groundlizards, Pholidoscelis exsul (Squamata: Teiidae), on Guana Island, British Virgin Islands

Invasive species are a major threat and primary driver of vertebrate extinctions on islands, including native and endemic lizards such as West Indian Groundlizards (Genus Pholidoscelis). The genus comprises 19 extant species that range collectively from the Bahamas through the Greater Antilles south to Dominica in the Lesser Antilles. Few studies have addressed aspects of Groundlizard population ecology despite invasive mammals being implicated in Groundlizard declines and three extinctions. From 2007 to 2011, we conducted a capture–recapture study of Puerto Rican Giant Groundlizards (Pholidoscelis exsul) on Guana Island. Guana Island is privately owned and hosts a small number of feral cats, but is mongoose-free and has otherwise experienced only minor human modification since the mid-18th Century. Thus, the island provides a unique opportunity to study lizard demography under conditions minimally impacted by human activities. Our objective was to establish benchmark demographic parameter estimates of P. exsul that may be used in future studies to detect ecological changes. We hypothesized that lizards would be encountered more frequently in disturbed habitat than in less-disturbed habitat because of available anthropogenic food subsidies. We also predicted that large lizards would have higher annual survival rates than would small lizards, and lizards with higher indices of body condition would have correspondingly higher annual survival rates than lizards of the same size class with lower indices of body condition. Our results showed that male growth rates were comparable to similar studies, and individuals reached the presumed size of sexual maturity within 1 yr, with growth rates declining thereafter. Annual survival increased with size class (small = 0.155, 95% confidence interval [CI] = 0.069–0.312; large = 0.518, 95% CI = 0.374–0.660), but we found no evidence of a body condition effect on annual survival. The probability of mortality increased to 99.4% by age 6, but evidence of senescence via declining body condition was apparent sooner. Daily capture probabilities were higher in heavily modified habitat (0.081, 95% CI = 0.049–0.132) than in relatively natural habitat (0.025, 95% CI = 0.012–0.054). Mean maximum distance moved between recaptures was 24.4 m (2–350 m). Estimates of annual abundance ranged from 139 to 250 individuals. Density estimates among years based on the upper confidence limit ranged from 41.9–81.5 individuals/ha within the core sampling area (6.01 ha) and 20.1–39.2 individuals/ha when a 12.5-m buffer strip was incorporated into the effective sampling area.

Global ecomorphological restructuring of dominant marine reptiles prior to the Cretaceous-Palaeogene mass extinction.

Mosasaurid squamates were the dominant amniote predators in marine ecosystems during most of the Late Cretaceous. Here, we use a suite of biomechanically rooted, functionally descriptive ratios in a framework adapted from population ecology to investigate how the morphofunctional disparity of mosasaurids evolved prior to the Cretaceous-Palaeogene (K/Pg) mass extinction. Our results suggest that taxonomic turnover in mosasaurid community composition from Campanian to Maastrichtian is reflected by a notable global increase in morphofunctional disparity, especially driving the North American record. Ecomorphospace occupation becomes polarized during the Late Maastrichtian, with morphofunctional disparity plateauing in the Southern Hemisphere and decreasing in the Northern Hemisphere. We show that these changes are not strongly associated with mosasaurid size, but rather with the functional capacities of their skulls. Our novel approach indicates that mosasaurid morphofunctional disparity was in decline in multiple provincial communities before the K/Pg mass extinction, highlighting region-specific patterns of disparity evolution and the importance of assessing vertebrate extinctions both globally and locally. Ecomorphological differentiation in mosasaurid communities, coupled with declines in other formerly abundant marine reptile groups, indicates widespread restructuring of higher trophic levels in marine food webs was well underway when the K/Pg mass extinction took place.

An inconvenient misconception: Climate change is not the principal driver of biodiversity loss

AbstractThe current perception that climate change is the principal threat to biodiversity is at best premature. Although highly relevant, it detracts focus and effort from the primary threats: habitat destruction and overexploitation. We collated causes of vertebrate extinctions since 1900, threat information for amphibia, birds, and mammals from the IUCN Red List, and scrutinized others’ attempts to compare climate change with commensurate anthropogenic threats. In each analysis, none of the arguments founded on climate change's wide‐ranging effects are as urgent for biodiversity as those for habitat loss and overexploitation. Present conservation efforts must refocus on these issues. Conserving ecosystems by focusing on these major threats not only protects biodiversity but is the only available, economically viable, global strategy to reverse climate change.

Forests Without Frugivores and Frugivores Without Forests – An Investigation Into the Causes of a Paradox in One of the Last Archipelagos Colonized by Humans

The Mascarenes are sadly famous worldwide for the massive extinction of their native vertebrates since recent human colonization. However, extinction patterns show astonishing disparities between the two main islands and between lineages of forest vertebrates. On Réunion (2,512 km2, 3,070 m) where about a third of native habitats remains, most large-bodied vertebrates, especially frugivores, collapsed by the first half of the 18th century, while several have survived longer and some still exist on Mauritius (1,865 km2, 828 m) where more than 95% of native habitats have been transformed. Considering lineages of forest vertebrates shared by both islands (23 genera, 53 species), we test the hypothesis that differing patterns of lowland suitable habitat destruction is the main cause behind this paradox. Before that, we assess the potential impact of other major drivers of extinctions since first contact with humans. Firstly, Mauritius shows earlier and more numerous introductions of mammal predators known for their devastating impact (except northern islets which have thus become important sanctuaries for several squamates). Secondly, settlers were inveterate hunters on both islands, but while Réunion was overhunted before Mauritius, the burst of human population in the latter in late 18th century has not led to the rapid extinction of all large native vertebrates. These two factors alone therefore cannot explain the observed paradox. Rather, the early destruction of lowland habitats (<400 m) on Réunion is concomitant with most extinctions of forest vertebrate, notably frugivores that rapidly lost most lowland habitats dominated by large fleshy-fruited plants. Moreover, landform-induced fragmentation has likely decreased the ability of adjacent habitats to act as effective refuges. Conversely, Mauritius retained suitable low-fragmented habitats until the late 19th which probably allowed, at least for a time, several native vertebrates to escape from multiple human-induced disturbances. Despite the almost total destruction of native habitats since then on Mauritius, conservation actions have saved several threatened vertebrate species that play a fundamental role in the functioning of native ecosystems. The fact that there are now more favorable habitats on Réunion than on Mauritius argues for the rewilding of Réunion with these extant large vertebrates.

Trading Animal Lives: Ten Tricky Issues on the Road to Protecting Commodified Wild Animals.

Wildlife commodification can generate benefits for biodiversity conservation, but it also has negative impacts; overexploitation of wildlife is currently one of the biggest drivers of vertebrate extinction risk. In the present article, we highlight 10 issues that in our experience impede sustainable and humane wildlife trade. Given humanity's increasing demands on the natural world we question whether many aspects of wildlife trade can be compatible with appropriate standards for biodiversity conservation and animal welfare, and suggest that too many elements of wildlife trade as it currently stands are not sustainable for wildlife or for the livelihoods that it supports. We suggest that the onus should be on traders to demonstrate that wildlife use is sustainable, humane, and safe (with respect to disease and invasion risk), rather than on conservationists to demonstrate it is not, that there is a need for a broad acceptance of responsibility and, ultimately, widespread behavior change. We urge conservationists, practitioners, and others to take bold, progressive steps to reach consensus and action.

Slow life history leaves endangered snake vulnerable to illegal collecting

Global wildlife trade is a multibillion-dollar industry and a significant driver of vertebrate extinction risk. Yet, few studies have quantified the impact of wild harvesting for the illicit pet trade on populations. Long-lived species, by virtue of their slow life history characteristics, may be unable to sustain even low levels of collecting. Here, we assessed the impact of illegal collecting on populations of endangered broad-headed snakes (Hoplocephalus bungaroides) at gated (protected) and ungated (unprotected) sites. Because broad-headed snakes are long-lived, grow slowly and reproduce infrequently, populations are likely vulnerable to increases in adult mortality. Long-term data revealed that annual survival rates of snakes were significantly lower in the ungated population than the gated population, consistent with the hypothesis of human removal of snakes for the pet trade. Population viability analysis showed that the ungated population has a strongly negative population growth rate and is only prevented from ultimate extinction by dispersal of small numbers of individuals from the gated population. Sensitivity analyses showed that the removal of a small number of adult females was sufficient to impose negative population growth and suggests that threatened species with slow life histories are likely to be especially vulnerable to illegal collecting.

Turtle biodiversity losses suggest coming sixth mass extinction

Biodiversity losses in the face of climate change are among the most important issues facing humanity today. Vertebrate extinction is at an all-time high, and losses of reptiles are no exception. The turtles are a unique vertebrate group of grave conservation concern. I compared recent declines in turtle biodiversity to the losses of Testudinata (Cryptodira + Pleurodira) and non-dinosaurian reptiles during the most recent mass extinction. Fuzzy arithmetic was used because of its suitability to deal with uncertainty in these kinds of data sets and the questions that arise with comparing geological data with those from recent times. This revealed that extinctions of turtles in modern times massively exceed losses observed at the Cretaceous–Paleogene border. Further, if turtle extinctions continued at their current level, massive losses of these charismatic animals could occur within our lifetime and loss of the entire group could occur in just a few centuries. We must ask ourselves, how much more can we lose before we also disappear.

Were human-introduced diseases the responsible for Pleistocene-Holocene megafaunal extinctions? First evidence from South America

Diverse hypotheses have been proposed with the aim to explain the extinction of Late Pleistocene/Holocene mammals, including the Megafauna from America. Some authors support that human being was the direct responsible of extinction by means of intensive hunting, as proposed by the “blitzkrieg” or overkilling hypothesis. However, evidence is not conclusive. As is well known by biologists, exotic diseases may play an important role in local extinction of diverse vertebrates. On this basis, some speculated that the arrival of man may also have introduced new diseases that may have played an important role on native mammals, especially megafaunal populations, probably constituting a key factor on their extinction. Recent findings of the parasite Fasciola hepatica in endemic deer from Holocene sites in Patagonia (and also probably from camelids in Peru) previous to Hispanic colonization constitute indirect evidence that may sustain this hypothesis. Because one of the main definite host of this parasite are humans, this potential disease may have been introduced by human populations as hosts and then disperse through the entire continent, as evidenced by the finding of Fasciola hepatica in Patagonia. Its presence in endemic deer and camelids previous to Hispanic colonization, reinforces the proposal that human-related diseases may have played some role in Late Pleistocene extinction of large native mammals.

Before, during and after megafaunal extinctions: Human impact on Pleistocene-Holocene trophic networks in South Patagonia

Worldwide extinctions of large terrestrial vertebrates in the late Pleistocene provide insight on how humans reshape ecological communities. Understanding the ecological causes and consequences of megafaunal extinctions requires integrating approaches to reconstruct the ecological communities from the past. Here, we combined archeological and paleontological evidence with network analyses to understand the changes in ecological communities from late Pleistocene to the Holocene in South Patagonia, the last continental region where the encounter between humans and extinct megafauna occurred. The zooarcheological record suggests humans would have interacted mainly with large-bodied species, which comprise a small subset of the available prey. Accordingly, using network reconstructions and structural analyses, we found that human arrival would have produced minor changes in the overall structure of trophic networks. However, those few novel interactions established by humans would have created multiple indirect paths among megafaunal species. Indirect paths are the route for indirect effects such as competition and increase the vulnerability of interaction networks to perturbations. After the extinctions of most of the megafauna, the impoverished network became structurally simpler and densely connected. Our reconstructions of past trophic networks show that multiple indirect effects, potentially contributing to extinctions, can emerge even from a limited number of novel interactions and illustrate how network organization can affect and be affected by extinctions events.

Human carnivory as a major driver of vertebrate extinction

Although a considerable part of the anthropogenic impacts on other species has been caused by our habit of eating other animals, little attention has been given to understanding and quantifying how human carnivory threatens biodiversity globally. Herein we review the anthropogenic threats to 1000 species randomly selected among more than 46,000 vertebrate entries in the IUCN Red List database. We identified the following mechanisms by which human carnivory (i.e., our habit of feeding on other animals and related products) negatively affects the world's vertebrates: two mechanisms related to predation (predation and bycatch), two to competition (prey depletion and persecution), one to biohazards (any negative impacts caused by livestock or alien species whose introduction is linked to human carnivory), four to environmental changes (destructive harvesting practices, livestock, agriculture, and climate change), and a miscellaneous category for processes more indirectly connected with our high trophic position. Our conservative estimate, which does not include livestock impacts via agriculture and climate change, reveals that about one-quarter of the world's vertebrates are threatened by at least one mechanism related to human carnivory, and that this proportion is higher than that attributable to other leading causes of biodiversity decline including agriculture, forestry, infrastructure, pollution, invasive species, energy production and mining, fire regime and water systems modifications, and climate change. Our results suggest that human carnivory is the major driver of the current biodiversity crisis, and we hope our findings may contribute to raise awareness about this fundamental yet overlooked aspect of human ecology.

Assessing the role of humans in Greater Antillean land vertebrate extinctions: New insights from Cuba

The Caribbean archipelago is a hotspot of biodiversity characterized by a high rate of extinction. Recent studies have examined these losses, but the causes of the Antillean Late Quaternary vertebrate extinctions, and especially the role of humans, are still unclear. Previous results provide support for climate-related and human-induced extinctions, but often downplaying other complex bio-ecological factors that are difficult to model or to detect from the fossil and archaeological record. Here, we discuss Caribbean vertebrate extinctions and the potential role of humans derived from new and existing fossil and archaeological data from Cuba. Our results indicate that losses of Cuba’s native fauna occurred in waves: one during the late Pleistocene and early Holocene, a second during the middle Holocene, and a third one during the last 2 ka, combining the arrival of agroceramists and later of Europeans. The coexistence of now-extinct species with multiple cultural groups in Cuba for over 4 ka implies that Cuban indigenous non-ceramic cultures exerted far fewer extinction pressures to native fauna than the later agroceramists and Europeans that followed. This suggests a determinant value to increased technological sophistication and demographics as plausible effective extinction drivers. Beyond looking at dates of first human arrival alone, future studies should also consider cultural diversity with attention to different bio-ecological factors that influence these biodiversity changes.

Alarming evidence of widespread mite extinctions in the shadows of plant, insect and vertebrate extinctions

AbstractThis paper, which addresses the issue of the extinction of mite species at the global scale for the first time, highlights mite diversity, assesses the evidence for an extinction process, discusses contributing factors and estimates losses. The ~1 250 000 mite species occupy an enormous variety of terrestrial and freshwater ecosystems from the equator to the polar regions and to high altitudes. Some groups provide essential ecosystem services, including the incorporation of organic matter into the soil. The maintenance of mite diversity is inextricably linked to the continuance of floristic diversity, habitat complexity and insect diversity. The majority of mite species are assumed to be in the tropical rainforests, of which >50% has been destroyed or severely degraded. Most biodiversity hotspots are in tropical forests; endemic phytoseiid mite species are at least 17 times more concentrated in the hotspots than outside. Habitat destruction and degradation continue on an enormous scale, with increasing human population growth and resource consumption the overarching drivers of extinction. Moreover, climate change is likely to be worsening the effects of the other drivers at an increasing rate. The small body of direct evidence and a considerable body of indirect evidence strongly suggest the continuing, widespread extinction of mite species. Based on estimates of overall biodiversity loss, ~15% of mite species were likely to have become extinct by 2000, with losses currently expected to increase by between 0.6% and 6.0% by 2060. More detailed information on both spatial differences in mite assemblages and anthropogenic threats worldwide is crucial because they underpin the total number of species and their vulnerability to extinction, respectively. The rapid expansion of the protected area estate to capture the maximum possible area of ecosystem heterogeneity, especially in the biodiversity hotspots, is essential, as is best practice management of these areas.

Mid-Cenozoic climate change, extinction, and faunal turnover in Madagascar, and their bearing on the evolution of lemurs

BackgroundWas there a mid-Cenozoic vertebrate extinction and recovery event in Madagascar and, if so, what are its implications for the evolution of lemurs? The near lack of an early and mid-Cenozoic fossil record on Madagascar has inhibited direct testing of any such hypotheses. We compare the terrestrial vertebrate fauna of Madagascar in the Holocene to that of early Cenozoic continental Africa to shed light on the probability of a major mid-Cenozoic lemur extinction event, followed by an “adaptive radiation” or recovery. We also use multiple analytic approaches to test competing models of lemur diversification and the null hypothesis that no unusual mid-Cenozoic extinction of lemurs occurred.ResultsComparisons of the terrestrial vertebrate faunas of the early Cenozoic on continental Africa and Holocene on Madagascar support the inference that Madagascar suffered a major mid-Cenozoic extinction event. Evolutionary modeling offers some corroboration, although the level of support varies by phylogeny and model used. Using the lemur phylogeny and divergence dates generated by Kistler and colleagues, RPANDA and TESS offer moderate support for the occurrence of unusual extinction at or near the Eocene-Oligocene (E-O) boundary (34 Ma). TreePar, operating under the condition of obligate mass extinction, found peak diversification at 31 Ma, and low probability of survival of prior lineages. Extinction at the E-O boundary received greater support than other candidate extinctions or the null hypothesis of no major extinction. Using the lemur phylogeny and divergence dates generated by Herrera & Dàvalos, evidence for large-scale extinction diminishes and its most likely timing shifts to before 40 Ma, which fails to conform to global expectations.ConclusionsWhile support for large-scale mid-Cenozoic lemur extinction on Madagascar based on phylogenetic modeling is inconclusive, the African fossil record does provide indirect support. Furthermore, a major extinction and recovery of lemuriforms during the Eocene-Oligocene transition (EOT) would coincide with other major vertebrate extinctions in North America, Europe, and Africa. It would suggest that Madagascar’s lemurs were impacted by the climate shift from “greenhouse” to “ice-house” conditions that occurred at that time. This could, in turn, help to explain some of the peculiar characteristics of the lemuriform clade.