1,721,116 research outputs found
Unexpected diversity within the extinct elephant birds (Aves: Aepyornithidae) and a new identity for the world's largest bird
Full text linkMadagascar’s now-extinct radiation of large-bodied ratites, the
elephant birds (Aepyornithidae), has been subject to little modern
research compared to the island’s mammalian megafauna and
other Late Quaternary giant birds. The family’s convoluted and
conflicting taxonomic history has hindered accurate interpretation
of morphological diversity and has restricted modern research into
their evolutionary history, biogeography and ecology. We present
a new quantitative analysis of patterns of morphological diversity
of aepyornithid skeletal elements, including material from all
major global collections of aepyornithid skeletal remains, and
constituting the first taxonomic reassessment of the family for over
50 years. Linear morphometric data collected from appendicular
limb elements, and including nearly all type specimens, were
examined using multivariate cluster analysis and the Bayesian
information criterion, and with estimation of missing data using
multiple imputation and expectation maximization algorithms.
These analyses recover three distinct skeletal morphotypes within
the Aepyornithidae. Two of these morphotypes are associated
with the type specimens of the existing genera Mullerornis and
Aepyornis, and represent small-bodied and medium-bodied
aepyornithids, respectively. Aepyornis contains two distinct
morphometric subgroups, which are identified as the largely
allopatric species A. hildebrandti and A. maximus. The third
morphotype, which has not previously been recognized as a
distinct genus, is described as the novel taxon Vorombe titan.
Vorombe represents the largest-bodied aepyornithid and is the
world’s largest bird, with a mean body mass of almost 650 kg.
This new taxonomic framework for the Aepyornithidae provides
an important new baseline for future studies of avian evolution
and the Quaternary ecology of Madagascar
Correction to ‘Unexpected diversity within the extinct elephant birds (Aves: Aepyornithidae) and a new identity for the world's largest bird’
Full text linkThis correction is to fulfil the requirements of the International Commission on Zoological Nomenclature (ICZN) article 8.5.3 [1] for the publication of new taxonomic names. In order for the genus Vorombe to be an available nomen, this name needed to be registered in ZooBank at the time of publication, with the ZooBank number appearing with the publication [2]. This correction aims to solve this issue, and the ZooBank LSID number is shown below along with a reiteration of the systematic section. The original work [2] should be cited along with this correction when citing this genus name
Correction to "Extinct insular oryzomyine rice rats (Rodentia: Sigmodontinae) from the Grenada Bank, southern Caribbean" (Zootaxa 4951 (3): 434-460) and reply to Ronez and Pardiñas (2021)
No full textWeksler, Marcelo, Giovas, Christina M., Mistretta, Brittany A., Turvey, Samuel T. (2021): Correction to "Extinct insular oryzomyine rice rats (Rodentia: Sigmodontinae) from the Grenada Bank, southern Caribbean" (Zootaxa 4951 (3): 434-460) and reply to Ronez and Pardiñas (2021). Zootaxa 5061 (2): 392-392, DOI: https://doi.org/10.11646/zootaxa.5061.2.1
Taxonomy, phylogeny, and diversity of the extinct Lesser Antillean rice rats (Sigmodontinae: Oryzomyini), with description of a new genus and species
No full textRice rats (Sigmodontinae: Oryzomyini) are abundant in the Late Quaternary fossil record and in Holocene pre-Columbian archaeological middens across the Lesser Antilles. All of these rice rats are now extinct, and their regional diversity and systematics remain extremely poorly understood. We redescribe all of the region's rice rat taxa known from adequate diagnostic material (Megalomys desmarestii, Megalomys luciae, and Oligoryzomys victus), and describe a new genus and species, Pennatomys nivalis gen. et sp. nov., from archaeological sites on St. Eustatius, St. Kitts, and Nevis, which formed a single larger island during Quaternary low sea-level stands. Cladistic analysis supports the inclusion of O. victus within Oligoryzomys, and identifies Megalomys as a sister group of the large-bodied genera Sigmodontomys or Sigmodontomys + Nectomys, suggesting that large body size in Megalomys represents phyletic gigantism rather than ‘island gigantism’. Megalomys and Pennatomys belong to an oryzomyine clade that has undergone remarkable radiation throughout the oceanic and continental-shelf islands of the Neotropical region, but these genera do not represent a monophyletic group within the Nectomys subclade, indicating multiple over-water colonization events of the Lesser Antillean island chain. Although Lesser Antillean rice rats were heavily exploited by prehistoric Amerindians, it is likely that most or all of these taxa survived until European arrival in the region.<br/
FIGURE 2 in A new subspecies of hutia (Plagiodontia, Capromyidae, Rodentia) from southern Hispaniola
Full text linkFIGURE 2. Principal Component Analysis for non-reduced dataset of craniodental measurements of southeastern palaeoisland hutias (squares), Plagiodontia aedium hylaeum (triangles), Plagiodontia aedium aedium (circles), and holotype of Plagiodontia aedium aedium (diamond). Percentage variation explained by PCA: axis 1, 43.41%; axis 2, 11.36%; cumulative variation, 54.78%.Published as part of Turvey, Samuel T., Hansford, James, Kennerley, Rosalind J., Nuñez-Miño, José M., Brocca, Jorge L. & Young, Richard P., 2015, A new subspecies of hutia (Plagiodontia, Capromyidae, Rodentia) from southern Hispaniola, pp. 201-214 in Zootaxa 3957 (2) on page 205, DOI: 10.11646/zootaxa.3957.2.4, http://zenodo.org/record/24026
A new species of extinct Late Quaternary giant tortoise from Hispaniola
No full textInsular giant tortoise diversity has been depleted by Late Quaternary extinctions, but the taxonomic status of many extinct populations remains poorly understood due to limited available fossil or subfossil material, hindering our ability to reconstruct Quaternary island biotas and environments. Giant tortoises are absent from current-day insular Caribbean ecosystems, but tortoise remains from Quaternary deposits indicate the former widespread occurrence of these animals across the northern Caribbean. We report new Quaternary giant tortoise material from several cave sites in Pedernales Province, southern Dominican Republic, Hispaniola, representing at least seven individuals, which we describe as Chelonoidis marcanoi sp. nov. Although giant tortoise material was first reported from the Quaternary record of Hispaniola almost 35 years ago, tortoises are absent from most Quaternary deposits on the island, which has been studied extensively over the past century. The surprising abundance of giant tortoise remains in both vertical and horizontal caves in Hispaniola’s semi-arid ecoregion may indicate that this species was adapted to open dry habitats and became restricted to a habitat refugium in southeastern Hispaniola following climatic-driven environmental change at the Pleistocene-Holocene boundary. Hispaniola’s dry forest ecosystem may therefore have been shaped by giant tortoises for much of its evolutionary history
FIGURE 5 in A new subspecies of hutia (Plagiodontia, Capromyidae, Rodentia) from southern Hispaniola
No full textFIGURE 5. Living individuals of Plagiodontia aedium bondi: a, typical individual, photographed on 5 November 2009 near Mencia (18°10'49"N, 71°44'40"W); b, albino individual, photographed on 29 November 2009 at Fondo Paradi, Parque Nacional Jaragua (17°47'36"N, 71°27'57"W).Published as part of Turvey, Samuel T., Hansford, James, Kennerley, Rosalind J., Nuñez-Miño, José M., Brocca, Jorge L. & Young, Richard P., 2015, A new subspecies of hutia (Plagiodontia, Capromyidae, Rodentia) from southern Hispaniola, pp. 201-214 in Zootaxa 3957 (2) on page 210, DOI: 10.11646/zootaxa.3957.2.4, http://zenodo.org/record/24026
Holocene range collapse of giant muntjacs and pseudo-endemism in the Annamite large mammal fauna
No full textAim:To clarify the post-glacial biogeography of the Annamite and eastern Chinese ungulate faunas, and determine whether current understanding of Asian mammalian biogeography is biased by pseudo-extinctions and pseudo-endemism associated with a historical extinction filter.Location:Modern-day specimens of giant muntjac (Muntiacus vuquangensis) from the Annamite Mountains of Laos and Vietnam were compared with zooarchaeological specimens of extinct giant muntjac (M. gigas) from eastern China, and with a reference sample of northern red muntjac (M. vaginalis) from China, Southeast Asia and South Asia.Methods:We analysed a data set of antler measurements using Multivariate analyses of variance (MANOVAs), principal component analyses (PCAs) and scaling relationships, to quantify morphometric variation between extinct and living giant muntjacs in relation to variation shown by a different sympatric large-bodied muntjac species. We also attempted ancient biomolecule analysis of Holocene samples from China.Results:Although the combined giant muntjac sample can be differentiated from the reference red muntjac sample in all of our multivariate morphometric analyses, no significant differences are shown between extinct and living giant muntjacs using any analyses, matching the pattern seen when comparing conspecific red muntjac samples from across the same geographical region.Main conclusions:We find no support for recognizing extinct and living giant muntjacs as distinct taxa, and post-glacial populations from China and the Annamites should probably all be referred to M. gigas. The likely conspecificity of giant muntjacs across Eastern and Southeast Asia demonstrates that current-day Asian mammalian biogeography has been shaped by an extinction filter and challenges the idea that the Annamite region represents a cradle of evolution; instead, it may represent a refuge of diversity for some taxa, preserving remnant pseudo-endemic populations of species that have been extirpated across other parts of their former ranges
Early holocene human presence in Madagascar evidenced by exploitation of avian megafauna
No full textPrevious research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis, which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss.</p
Accelerating population decline of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis)
No full textThe Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is now the only cetacean species in the Yangtze River following the probable extinction of the baiji (Lipotes vexillifer). However, population abundance estimates and genetic diversity studies both indicate that the porpoise population is declining and may also become extinct in the wild in the near future. We used data from 279 stranded porpoises that were collected along the middle and lower reaches of the Yangtze River since 1978 to construct life tables for the porpoise population before and after 1993. Demographic rate estimates reveal an accelerating decline of the Yangtze porpoise population according to the instantaneous rate of increase ((r) over bar), from (r) over bar = -0.0159 (SD = 0.0135) to (r) over bar = -0.0625 (SD = 0.0169). Using an individual-based Leslie matrix model, there is a high probability of extinction (86.06%) within the next 100 years. Effective conservation measures must be enacted immediately. The pattern of cetacean decline and extinction in the Yangtze provides a startling demonstration of how rapid economic development without adequate environmental control leads to deterioration of natural habitats and threatens native species extremely rapid. This research also emphasizes the need for precautionary conservation action in other riverine systems containing freshwater cetacean species. (C) 2012 Elsevier Ltd. All rights reserved.The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is now the only cetacean species in the Yangtze River following the probable extinction of the baiji (Lipotes vexillifer). However, population abundance estimates and genetic diversity studies both indicate that the porpoise population is declining and may also become extinct in the wild in the near future. We used data from 279 stranded porpoises that were collected along the middle and lower reaches of the Yangtze River since 1978 to construct life tables for the porpoise population before and after 1993. Demographic rate estimates reveal an accelerating decline of the Yangtze porpoise population according to the instantaneous rate of increase ((r) over bar), from (r) over bar = -0.0159 (SD = 0.0135) to (r) over bar = -0.0625 (SD = 0.0169). Using an individual-based Leslie matrix model, there is a high probability of extinction (86.06%) within the next 100 years. Effective conservation measures must be enacted immediately. The pattern of cetacean decline and extinction in the Yangtze provides a startling demonstration of how rapid economic development without adequate environmental control leads to deterioration of natural habitats and threatens native species extremely rapid. This research also emphasizes the need for precautionary conservation action in other riverine systems containing freshwater cetacean species. (C) 2012 Elsevier Ltd. All rights reserved
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