Find research datasets worth reusing

opennotspecifiedDec 2019View details →

FIGURE 6. Scale-shaped sclerites under polarized light showing concentric extinction patterns. A in A review of the genus Trichogorgia (Cnidaria, Octocorallia), including descriptions of new species

FIGURE 6. Scale-shaped sclerites under polarized light showing concentric extinction patterns. A: Stephanogorgia diomedea (USNM 75108); B: Trichogorgia lyra (USNM 52875); C: S. wainwrighti (USNM 1112682); D: T. muzikae sp. nov. (USNM 77155, holotype).

opennotspecifiedOct 2019View details →

Subspecies and Distribution. E. s. semicaudata Peale, 1848 - Samoa (Savai'i and Upolu Is), American Samoa (Ta'u Is), Fiji (Rotuma, Kuata in Yusawa Group, Taveuni, Ovalau, and Lakeba Is), and Tonga (Niuafo'ou and 'Eua Is, and likely occurs on other islands in the group). Not recorded in Tutuila (American Samoa) since 1976 despite dedicated searches for cave roosts and use of echolocation detectors and also likely extinct on Vitu Levu (Fiji) where the last specimens were collected in 1979. E. s. palauensis Yamashima, 1932 - Palau Is (including Babeldaob, Koror, Peleliu, and Angaur). E. s. rotensis Yamashima, 1943 - Northern Mariana Is and Guam I, last surviving population is currently restricted to tiny Aguigan I; it appears to be extirpated on Anatahan, Tonowas, Rota, Saipan, and Tinian Is, and on Guam I. E. s. sulcataG. S. Miller, 1911 — Caroline Is (Chuuk and Pohnpei Is). in Emballonuridae

Subspecies and Distribution. E. s. semicaudata Peale, 1848 - Samoa (Savai'i and Upolu Is), American Samoa (Ta'u Is), Fiji (Rotuma, Kuata in Yusawa Group, Taveuni, Ovalau, and Lakeba Is), and Tonga (Niuafo'ou and 'Eua Is, and likely occurs on other islands in the group). Not recorded in Tutuila (American Samoa) since 1976 despite dedicated searches for cave roosts and use of echolocation detectors and also likely extinct on Vitu Levu (Fiji) where the last specimens were collected in 1979. E. s. palauensis Yamashima, 1932 - Palau Is (including Babeldaob, Koror, Peleliu, and Angaur). E. s. rotensis Yamashima, 1943 - Northern Mariana Is and Guam I, last surviving population is currently restricted to tiny Aguigan I; it appears to be extirpated on Anatahan, Tonowas, Rota, Saipan, and Tinian Is, and on Guam I. E. s. sulcataG. S. Miller, 1911 — Caroline Is (Chuuk and Pohnpei Is).

opennotspecifiedOct 2019View details →

Distribution. SJapan, Okinawa Is, Iheyajima (one record in 1992), Tokashikijima (one record in 1978), Kumejima, Miyakojima (probably extinct after 1971), and Irabu Is. in Rhinolophidae

Distribution. SJapan, Okinawa Is, Iheyajima (one record in 1992), Tokashikijima (one record in 1978), Kumejima, Miyakojima (probably extinct after 1971), and Irabu Is.

opencc-by-4.0Jan 2010View details →

Sighting record data to estimate extinction likelihood for North American and Hawaiian birds

This is an updated version of Table S1 from Elphick, C.S., D.L. Roberts, and J.M. Reed. 2010. Estimated dates of recent extinctions for North American and Hawaiian birds. Biological Conservation 143: 617-624. The original version (Version 1) used in the paper was published as supplemental material to the paper and is available at: https://www.sciencedirect.com/science/article/pii/S0006320709004911?via%3Dihub#app1 This updated version (Version 2) was previously posted online at: http://hydrodictyon.eeb.uconn.edu/people/birdlab/Elphick_et_al_2010_supplement_18_Jan_10_update.pdf The table Sighting data used in analyses for Elphick et al. 2010. The citation number for each year within a sighting record is given by the superscript. We include data for species (or populations) that fit our analysis goals, but for which too few data were available to analyze in the hopes that others will be able to find additional sighting data. This data set is modified from that originally published on-line to incorporate additional information that has subsequently come to light (changes highlighted in blue). No changes in the statistical results that arose from the inclusion of new information (see bottom of the document). Yes, it's annoying its a .doc file (sorry - expediency is winning here ...)

opennotspecifiedJun 2020View details →

FIGURE 2 in Systematics of a survivor: the Cambrian kingstoniid trilobite Blountia Walcott, 1916 across the Marjuman-Steptoean (Guzhangian-Paibian) extinction interval in Laurentian North America

FIGURE 2. Phylogenetic analysis of Blountia and related taxa. 1. Strict consensus of six trees of length 30 (CI, 0.50; RI, 0.62; RC, 0.31). Names of species from Steptoean strata are identified by bold font. 2. Optimized character distribution plotted on one of the most parsimonious trees. Only unambiguous transformations (i.e., optimize to the same nodes under the assumptions of ACCTRAN and DELTRAN) are shown; open circles indicate characters that are homoplastic. Numbers above the circles refer to characters and those below identify particular states (Table 2).

opennotspecifiedJul 2020View details →

FIGURES 3–4 in Description of the first extinct member of the tribe Anaglyptini (Coleoptera: Cerambycidae) from European Tertiary

FIGURES 3–4. Acanthoglyptus picollus gen. et sp. nov., holotype: 3—habitus, ventrolateral view; 4—body, dorsolateral view. Scale bars represent 2.0 mm.

opennotspecifiedJul 2020View details →

FIGURES 1–2 in Description of the first extinct member of the tribe Anaglyptini (Coleoptera: Cerambycidae) from European Tertiary

FIGURES 1–2. Acanthoglyptus picollus gen. et sp. nov., holotype: 1—habitus, dorsolateral view; 2—forebody, dorsolateral view. Scale bars represent 2.0 mm.

opencc-zeroDec 2018View details →

Data from: Risk of extinction of a unique skate population due to predation by a recovering marine mammal

Benefitting from reduced harvesting and an end to culling, many marine mammals are now recovering from past overexploitation. These recoveries represent important conservation successes but present a serious conservation problem when the recovering mammals are predators of species of conservation concern. Here we examine the role of predation by recovering grey seals (Halichoerus grypus) in the near-extinction of a unique skate population in the southern Gulf of St. Lawrence (sGSL) in Atlantic Canada. Winter skate (Leucoraja ocellata) in the sGSL are distinct from winter skate elsewhere and may represent an endemic species. Their adult abundance has declined by 98% since 1980 and these skates are now detectable in only a small fraction of their former range. Population modelling indicates that the ongoing collapse of this population is due to increases in the natural mortality of adults. Based on model projections this population would be extinct by mid-century if its current rate of productivity were to persist. A second population model incorporated predation by grey seals. Model estimates of skate consumption by seals were consistent with historical and recent estimates of the contribution of skates to grey seal diets. The estimated consumption accounted for the increases in the natural mortality of adult skates. A Type III functional response for grey seals preying on winter skate emerged from the model results. This indicates that, when skate abundance is very low, grey seals are expected to switch to alternate prey, resulting in declines in the mortality of skates due to predation. Consequently, contrary to projections at current productivity, winter skate are expected to be trapped at very low abundance in a "predator pit" instead of declining to extinction. Nonetheless, extinction risk would remain very high at the very small population size in the predator pit. Our results emphasize the need for an ecosystem-based approach to the management of living resources in this ecosystem.

opencc-zeroSep 2020View details →

Data from: A framework for the integrated analysis of the magnitude, selectivity, and biotic effects of extinction and origination

The taxonomic and ecologic composition of Earth's biota has shifted dramatically through geologic time, with some clades going extinct while others diversified. Here, we derive a metric that quantifies the change in biotic composition due to extinction or origination and show that it equals the product of extinction/origination magnitude and selectivity (variation in magnitude among groups). We also define metrics that describe the extent to which a recovery (1) reinforced or reversed the effects of extinction on biotic composition and (2) changed composition in ways uncorrelated with the extinction. To demonstrate the approach, we analyzed an updated compilation of stratigraphic ranges of marine animal genera. We show that mass extinctions were not more selective than background intervals at the phylum level; rather, they tended to drive greater taxonomic change due to their higher magnitudes. Mass extinctions did not represent a separate class of events with respect to either strength of selectivity or effect. Similar observations apply to origination during recoveries from mass extinctions, and on average, extinction and origination were similarly selective and drove similar amounts of biotic change. Elevated origination during recoveries drove bursts of compositional change that varied considerably in effect. In some cases, origination partially reversed the effects of extinction, returning the biota towards the pre-extinction composition; in others, it reinforced the effects of the extinction, magnifying biotic change. Recoveries were as important as extinction events in shaping the marine biota, and their selectivity deserves systematic study alongside that of extinction.

An effect size statistical framework for investigating sexual dimorphism in non-avian dinosaurs and other extinct taxa

Despite reports of sexual dimorphism in extinct taxa, such claims in non-avian dinosaurs have been underrepresented recently (~the last decade) and often criticized. Since dimorphism is widespread in sexually reproducing organisms today, underrepresentation might suggest either methodological shortcomings or that this diverse group exhibited highly unusual reproductive biology. Univariate significance testing, especially for bimodality, is ineffective and prone to false negatives. Species recognition and mutual sexual selection hypotheses, therefore, may not be required to explain supposed absence of sexual dimorphism across the grade, likely a type II error. Instead, multiple lines of evidence support sexual selection and variation of structures consistent with secondary sexual characteristics, strongly suggesting sexual dimorphism in non-avian dinosaurs. We propose a framework for studying sexual dimorphism in fossils, focusing on likely secondarily sexual traits and testing against all alternate hypotheses for variation in them using multiple lines of evidence. We use effect size statistics appropriate for low sample sizes, rather than significance testing, to analyze potential divergence of growth curves in traits and constrain estimates for dimorphism magnitude. In many cases, estimates of sexual variation can be reasonably accurate, and further developments in methods to improve sex assignments and account for intrasexual variation (e.g., mixture modelling) will improve accuracy. It is better to compare estimates for the magnitude of and support for dimorphism between datasets than to dichotomously reject or fail to reject monomorphism in a single species, enabling the study of sexual selection across phylogenies and time. We defend our approach with simulated and empirical data, including dinosaur data, showing that even simple approaches can yield fairly accurate estimates of sexual variation in many cases, allowing for comparison of species with high and low support for sexual variation.

Figs 25–36 in Taxonomic revision of the genus Schildia Aldrich, 1923 (Diptera: Asilidae: Leptogastrinae) with the description of new extant and extinct species

Figs 25–36. Male terminalia with gonostyli (dark grey) and lateral processes of gonostyli (light grey) shaded in lateral views, abdominal T8, and wings of Schildia species. (25–27) Male terminalia of S. malaya sp.n.: 25, lateral; 26, dorsal; 27, ventral. (28–30) Male terminalia of S. microthorax. 28, lateral; 29, dorsal; 30, ventral. (31–33) Male terminalia and T8 of S. fragilis: 31, lateral; 32, dorsal; 33, ventral; 34, T8 dorsal. (35–36) Wings: 35, S. malaya sp.n.; 36, S. microthorax. Scale bars = 1 mm.

Figs 5–8 in Taxonomic revision of the genus Schildia Aldrich, 1923 (Diptera: Asilidae: Leptogastrinae) with the description of new extant and extinct species

Figs 5–8. SEM micrographs of head and metathoracic tarsus of Schildia microthorax (EMF, Costa Rica). (5) Head, anterior view; (6) head, dorsal view; (7) tarsus, lateral view; (8) detail of claws, lateral view. Scale bars = 100 µm.

Figs 2–4 in Taxonomic revision of the genus Schildia Aldrich, 1923 (Diptera: Asilidae: Leptogastrinae) with the description of new extant and extinct species

Figs 2–4. SEM micrographs of wing of Schildia microthorax (EMF, Costa Rica) with veins labeled. (2) Distal tip of wing; (3) detail of trichoid spicules; (4) posterior margin of wing. Scale bars = 50 µm.

Fig. 1 in Taxonomic revision of the genus Schildia Aldrich, 1923 (Diptera: Asilidae: Leptogastrinae) with the description of new extant and extinct species

Fig. 1. Map of the world with extant and extinct distribution of Schildia indicated with solid circles. Note the restricted Old World distribution in Madagascar and Malaysia.

Mating patterns influence vulnerability to the extinction vortex

Earth's biodiversity is undergoing mass extinction due to anthropogenic compounding of environmental, demographic and genetic stresses. These different stresses can trap populations within a reinforcing feedback loop known as the extinction vortex, in which synergistic pressures build upon one another through time, driving down population viability. Sexual selection, the widespread evolutionary force arising from competition, choice and reproductive variance within animal mating patterns, could have vital consequences for population viability and the extinction vortex: 1) if sexual selection reinforces natural selection to fix 'good genes' and purge 'bad genes', then mating patterns encouraging competition and choice may help protect populations from extinction; 2) by contrast, if mating patterns create load through evolutionary or ecological conflict, then population viability could be further reduced by sexual selection. We test between these opposing theories using replicate populations of the model insect Tribolium castaneum exposed to over ten years of experimental evolution under monogamous versus polyandrous mating patterns. After a 95-generation history of divergence in sexual selection, we compared fitness and extinction of monogamous versus polyandrous populations through an experimental extinction vortex comprising 15 generations of cycling environmental and genetic stresses. Results showed that lineages from monogamous evolutionary backgrounds, with limited opportunities for sexual selection, showed rapid declines in fitness and complete extinction through the vortex. By contrast, fitness of populations from the history of polyandry, with stronger opportunities for sexual selection, declined slowly, with 60% of populations surviving by the study end. The three vortex stresses of i) nutritional deprivation, ii) thermal stress and iii) genetic bottlenecking had similar impacts on fitness declines and extinction risk, with an overall sigmoid decline in survival through time. We therefore reveal sexual selection as an important force behind lineages facing extinction threats, identifying the relevance of natural mating patterns for conservation management.

Shifts in sexual dimorphism across a mass extinction in ostracods: implications for sexual selection as a factor in extinction risk

Sexual selection often favors investment in expensive sexual traits that help individuals compete for mates. In a rapidly changing environment, however, allocation of resources to traits related to reproduction at the expense of those related to survival may elevate extinction risk. Empirical testing of this hypothesis in the fossil record, where extinction can be directly documented, is largely lacking. The rich fossil record of cytheroid ostracods offers a unique study system in this context: the male shell is systematically more elongate than that of females, and thus the sexes can be distinguished, even in fossils. Using mixture models to identify sex clusters from size and shape variables derived from the digitized valve outlines of adult ostracods, we estimated sexual dimorphism in ostracod species before and after the Cretaceous/Paleogene mass extinction in the United States Coastal Plain. Across this boundary, we document a substantial shift in sexual dimorphism, driven largely by a pronounced decline in the taxa with dimorphism indicating both very high and very low male investment. The shift away from high male investment, which arises largely from evolutionary changes within genera that persist through the extinction, parallels extinction selectivity previously documented during the Late Cretaceous under a background extinction regime. Our results suggest that sexual selection and the allocation of resources towards survival versus reproduction may be an important factor for species extinction during both background and mass extinctions.

Data from Cretaceous-Paleogene plant extinction and recovery in Patagonia

The Cretaceous-Paleogene (K/Pg) extinction appears to have been geographically heterogeneous for some organismal groups. Southern Hemisphere K/Pg palynological records have shown lower extinction and faster recovery than in the Northern Hemisphere, but no comparable, well-constrained Southern Hemisphere macrofloras spanning this interval had been available. Here, macrofloral turnover patterns are addressed for the first time in the Southern Hemisphere, using over 3,500 dicot leaves from the latest Cretaceous (Maastrichtian) and the earliest Paleocene (Danian) of Argentine Patagonia. A maximum ca. 90% macrofloral extinction and ca. 45% drop in rarefied species richness is estimated across the K/Pg, consistent with substantial species-level extinction and previously observed extirpation of host-specialized leaf-mines. However, prior palynological and taxonomic studies indicate low turnover of higher taxa and persistence of general floral composition in the same sections. High species extinction, decreased species richness, and homogenous Danian macrofloras across time and facies resemble patterns often observed in North America, but there are several notable differences. When compared with boundary-spanning macrofloras at similar absolute paleolatitudes (ca. 50⁰S or N) from the Williston Basin (WB) in the Dakotas, both Maastrichtian and Danian Patagonian species richness are higher, extending a history of elevated South American diversity into the Maastrichtian. Despite high species turnover, our analyses also reveal continuity and expansion of leaf morphospace, including an increase in lobed and toothed species unlike the Danian WB. Thus, both Patagonian and WB K/Pg macrofloras support a significant extinction event, but they may also reflect geographically heterogeneous diversity, extinction, and recovery patterns warranting future study.