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1.
Zootaxa ; 4951(2): zootaxa.4951.2.6, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33903405

RESUMO

The nine currently recognized subspecies in the Brown Tinamou (Crypturellus obsoletus) complex are disjunctly widespread in South America, and at least three of them occur in Brazil. Morphological diagnosis of most of these taxa is imprecise, in contrast with consistent vocal differences described in the literature. We conducted a taxonomic review of two Amazonian taxa, C. o. griseiventris and C. o. hypochraceus, using morphological, morphometric, and vocal characters. Our results indicate that C. o. hypochraceus (Miranda-Ribeiro, 1938) is a junior synonym of C. o. griseiventris (Salvadori, 1895), and that Crypturellus griseiventris (Salvadori, 1895) must be treated as a full species, based on unique and fully diagnosable plumage and vocal patterns.


Assuntos
Paleógnatas , Animais , Aves , Classificação , Paleógnatas/classificação , Filogenia
2.
BMC Evol Biol ; 19(1): 233, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881941

RESUMO

BACKGROUND: Palaeognathae is a basal clade within Aves and include the large and flightless ratites and the smaller, volant tinamous. Although much research has been conducted on various aspects of palaeognath morphology, ecology, and evolutionary history, there are still areas which require investigation. This study aimed to fill gaps in our knowledge of the Southern Cassowary, Casuarius casuarius, for which information on the skeletal systems of the syrinx, hyoid and larynx is lacking - despite these structures having been recognised as performing key functional roles associated with vocalisation, respiration and feeding. Previous research into the syrinx and hyoid have also indicated these structures to be valuable for determining evolutionary relationships among neognath taxa, and thus suggest they would also be informative for palaeognath phylogenetic analyses, which still exhibits strong conflict between morphological and molecular trees. RESULTS: The morphology of the syrinx, hyoid and larynx of C. casuarius is described from CT scans. The syrinx is of the simple tracheo-bronchial syrinx type, lacking specialised elements such as the pessulus; the hyoid is relatively short with longer ceratobranchials compared to epibranchials; and the larynx is comprised of entirely cartilaginous, standard avian anatomical elements including a concave, basin-like cricoid and fused cricoid wings. As in the larynx, both the syrinx and hyoid lack ossification and all three structures were most similar to Dromaius. We documented substantial variation across palaeognaths in the skeletal character states of the syrinx, hyoid, and larynx, using both the literature and novel observations (e.g. of C. casuarius). Notably, new synapomorphies linking Dinornithiformes and Tinamidae are identified, consistent with the molecular evidence for this clade. These shared morphological character traits include the ossification of the cricoid and arytenoid cartilages, and an additional cranial character, the articulation between the maxillary process of the nasal and the maxilla. CONCLUSION: Syrinx, hyoid and larynx characters of palaeognaths display greater concordance with molecular trees than do other morphological traits. These structures might therefore be less prone to homoplasy related to flightlessness and gigantism, compared to typical morphological traits emphasised in previous phylogenetic studies.


Assuntos
Laringe/anatomia & histologia , Paleógnatas/anatomia & histologia , Paleógnatas/genética , Filogenia , Animais , Evolução Biológica , Feminino , Glote/anatomia & histologia , Masculino , Orofaringe/anatomia & histologia , Paleógnatas/classificação , Vocalização Animal
3.
PLoS Biol ; 17(10): e3000448, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31577791

RESUMO

The development of an organism involves the formation of patterns from initially homogeneous surfaces in a reproducible manner. Simulations of various theoretical models recapitulate final states of natural patterns, yet drawing testable hypotheses from those often remains difficult. Consequently, little is known about pattern-forming events. Here, we surveyed plumage patterns and their emergence in Galliformes, ratites, passerines, and penguins, together representing the three major taxa of the avian phylogeny, and built a unified model that not only reproduces final patterns but also intrinsically generates shared and varying directionality, sequence, and duration of patterning. We used in vivo and ex vivo experiments to test its parameter-based predictions. We showed that directional and sequential pattern progression depends on a species-specific prepattern: an initial break in surface symmetry launches a travelling front of sharply defined, oriented domains with self-organising capacity. This front propagates through the timely transfer of increased cell density mediated by cell proliferation, which controls overall patterning duration. These results show that universal mechanisms combining prepatterning and self-organisation govern the timely emergence of the plumage pattern in birds.


Assuntos
Galliformes/genética , Modelos Estatísticos , Paleógnatas/genética , Passeriformes/genética , Pigmentação/genética , Spheniscidae/genética , Animais , Cor , Embrião não Mamífero , Plumas/citologia , Plumas/crescimento & desenvolvimento , Plumas/metabolismo , Galliformes/anatomia & histologia , Galliformes/classificação , Galliformes/crescimento & desenvolvimento , Padrões de Herança , Morfogênese/genética , Paleógnatas/anatomia & histologia , Paleógnatas/classificação , Paleógnatas/crescimento & desenvolvimento , Passeriformes/anatomia & histologia , Passeriformes/classificação , Passeriformes/crescimento & desenvolvimento , Filogenia , Pele/citologia , Pele/crescimento & desenvolvimento , Pele/metabolismo , Spheniscidae/anatomia & histologia , Spheniscidae/classificação , Spheniscidae/crescimento & desenvolvimento
4.
Syst Biol ; 68(6): 937-955, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31135914

RESUMO

Palaeognathae represent one of the two basal lineages in modern birds, and comprise the volant (flighted) tinamous and the flightless ratites. Resolving palaeognath phylogenetic relationships has historically proved difficult, and short internal branches separating major palaeognath lineages in previous molecular phylogenies suggest that extensive incomplete lineage sorting (ILS) might have accompanied a rapid ancient divergence. Here, we investigate palaeognath relationships using genome-wide data sets of three types of noncoding nuclear markers, together totaling 20,850 loci and over 41 million base pairs of aligned sequence data. We recover a fully resolved topology placing rheas as the sister to kiwi and emu + cassowary that is congruent across marker types for two species tree methods (MP-EST and ASTRAL-II). This topology is corroborated by patterns of insertions for 4274 CR1 retroelements identified from multispecies whole-genome screening, and is robustly supported by phylogenomic subsampling analyses, with MP-EST demonstrating particularly consistent performance across subsampling replicates as compared to ASTRAL. In contrast, analyses of concatenated data supermatrices recover rheas as the sister to all other nonostrich palaeognaths, an alternative that lacks retroelement support and shows inconsistent behavior under subsampling approaches. While statistically supporting the species tree topology, conflicting patterns of retroelement insertions also occur and imply high amounts of ILS across short successive internal branches, consistent with observed patterns of gene tree heterogeneity. Coalescent simulations and topology tests indicate that the majority of observed topological incongruence among gene trees is consistent with coalescent variation rather than arising from gene tree estimation error alone, and estimated branch lengths for short successive internodes in the inferred species tree fall within the theoretical range encompassing the anomaly zone. Distributions of empirical gene trees confirm that the most common gene tree topology for each marker type differs from the species tree, signifying the existence of an empirical anomaly zone in palaeognaths.


Assuntos
Genoma/genética , Paleógnatas/classificação , Paleógnatas/genética , Filogenia , Animais , Genômica
5.
Zootaxa ; 4032(5): 493-514, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26624382

RESUMO

The extinct Lithornithidae include several genera and species of flying palaeognathous birds of controversial affinities known from the Early Paleogene of North America and Europe. An almost complete, articulated skeleton from the Early Eocene marine deposits of the Fur Formation (Denmark) was recently assigned to Lithornis vulturinus Owen, 1840. This study provides a detailed redescription and comparison of this three-dimensionally preserved specimen (MGUH 26770), which is one of the best preserved representatives of the Lithornithidae yet known. We suggest that some new features might be diagnostic of Lithornis vulturinus, including a pterygoid fossa shallower than in other species of Lithornis and the presence of a small caudal process on the os palatinum. We propose that Lithornis nasi (Harrison, 1984) is a junior synonym of Lithornis vulturinus and we interpret minor differences in size and shape among the specimens as intraspecific variation. To date, Lithornis vulturinus is known with certainty from the latest Paleocene-earliest Eocene to Early Eocene of the North Sea Basin (Ølst, Fur and London Clay Formations). Among the four species of the genus Lithornis, the possibility that Lithornis plebius Houde, 1988 (Early Eocene of Wyoming) is conspecific with either Lithornis vulturinus or Lithornis promiscuus Houde, 1988 (Early Eocene of Wyoming) is discussed. The presence of closely related species of Lithornis on either side of the North Atlantic in the Early Eocene reflects the existence of a high-latitude land connection between Europe and North America at that time.


Assuntos
Paleógnatas/anatomia & histologia , Paleógnatas/classificação , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Dinamarca , Fósseis/anatomia & histologia , Tamanho do Órgão , Paleógnatas/crescimento & desenvolvimento
6.
Artigo em Inglês | MEDLINE | ID: mdl-26123777

RESUMO

Ratites differ in the anatomy of their digestive organs and their digesta excretion patterns. Ostriches (Struthio camelus) have large fermentation chambers and long digesta retention, emus (Dromaius novaehollandiae) have a short gut and short retention times, and rheas (Rhea americana) are intermediate. A recent study showed that ostriches produce as much methane (CH4) as expected for a similar-sized, non-ruminant mammalian herbivore. We hypothesized that emus and rheas produce less CH4 than ostriches. We individually measured, by chamber respirometry, the amount of O2 consumed as well as CO2 and CH4 emitted from six adult rheas (body mass 23.4±8.3 kg) and two adult emus (33.5 and 32.0 kg) during 23-hour periods on a pelleted lucerne diet. In contrast to previous studies, which classified emus as non-producers, we measured CH4 emissions at 7.39 and 6.25 L/day for emus and 2.87±0.82 L/day for rheas, which is close to values expected for similar-sized non-ruminant mammals for both species. O2 consumption was of a similar magnitude as reported previously. Across ratites, CH4 yield (L/kg dry matter intake) was positively correlated with mean retention time of food particles in the gut, similar to findings within ruminant species. In ratites, this relationship leads to similar body mass-specific CH4 production for a high intake/short retention and a low intake/long retention strategy. Therefore, when investigating CH4 production in herbivorous birds, it is advisable to consider various CH4 measures, not only yield or absolute daily amount alone.


Assuntos
Digestão/fisiologia , Sistema Digestório/metabolismo , Ingestão de Alimentos/fisiologia , Metano/metabolismo , Paleógnatas/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal/fisiologia , Dióxido de Carbono/metabolismo , Dieta , Dromaiidae/metabolismo , Comportamento Alimentar/fisiologia , Feminino , Masculino , Paleógnatas/classificação , Reiformes/metabolismo , Especificidade da Espécie , Struthioniformes/metabolismo , Fatores de Tempo
7.
PLoS One ; 9(6): e99929, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24923666

RESUMO

BACKGROUND: The analysis of growth in extinct organisms is difficult. The general lack of skeletal material from a range of developmental states precludes determination of growth characteristics. For New Zealand's extinct moa we have available to us a selection of rare femora at different developmental stages that have allowed a preliminary determination of the early growth of this giant flightless bird. We use a combination of femora morphometrics, ancient DNA, and isotope analysis to provide information on the identification, classification, and growth of extinct moa from the genus Euryapteryx. RESULTS: Using ancient DNA, we identify a number of moa chick bones for the species Euryapteryx curtus, Dinornis novaezealandiae, and Anomalopteryx didiformis, and the first chick bone for Pachyornis geranoides. Isotope analysis shows that ∂15N levels vary between the two known size classes of Euryapteryx, with the larger size class having reduced levels of ∂15N. A growth series for femora of the two size classes of Euryapteryx shows that early femora growth characteristics for both classes are almost identical. Morphometric, isotopic, and radiographic analysis of the smallest Euryapteryx bones suggests that one of these femora is from a freshly hatched moa at a very early stage of development. CONCLUSION: Using morphometric, isotopic, and ancient DNA analyses have allowed the determination of a number of characteristics of rare moa chick femora. For Euryapteryx the analyses suggest that the smaller sized class II Euryapteryx is identical in size and growth to the extant Darwin's rhea.


Assuntos
DNA Mitocondrial/análise , Paleógnatas/classificação , Paleógnatas/crescimento & desenvolvimento , Paleógnatas/genética , Animais , Aves/anatomia & histologia , Aves/classificação , Aves/genética , Aves/crescimento & desenvolvimento , Desenvolvimento Ósseo , Osso e Ossos/anatomia & histologia , Osso e Ossos/diagnóstico por imagem , Clonagem Molecular , DNA Mitocondrial/genética , Meio Ambiente , Nova Zelândia , Paleógnatas/anatomia & histologia , Paleontologia , Radiografia , Datação Radiométrica , Análise de Sequência de DNA
8.
Mol Biol Evol ; 31(7): 1686-96, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24825849

RESUMO

One of the most startling discoveries in avian molecular phylogenetics is that the volant tinamous are embedded in the flightless ratites, but this topology remains controversial because recent morphological phylogenies place tinamous as the closest relative of a monophyletic ratite clade. Here, we integrate new phylogenomic sequences from 1,448 nuclear DNA loci totaling almost 1 million bp from the extinct little bush moa, Chilean tinamou, and emu with available sequences from ostrich, elegant crested tinamou, four neognaths, and the green anole. Phylogenetic analysis using standard homogeneous models and heterogeneous models robust to common topological artifacts recovered compelling support for ratite paraphyly with the little bush moa closest to tinamous within ratites. Ratite paraphyly was further corroborated by eight independent CR1 retroposon insertions. Analysis of morphological characters reinterpreted on a 27-gene paleognath topology indicates that many characters are convergent in the ratites, probably as the result of adaptation to a cursorial life style.


Assuntos
Paleógnatas/classificação , Paleógnatas/genética , Adaptação Fisiológica , Animais , Teorema de Bayes , Evolução Molecular , Genoma , Funções Verossimilhança , Modelos Genéticos , Paleógnatas/anatomia & histologia , Paleógnatas/fisiologia , Filogenia , Análise de Sequência de DNA
10.
Science ; 344(6186): 898-900, 2014 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-24855267

RESUMO

The evolution of the ratite birds has been widely attributed to vicariant speciation, driven by the Cretaceous breakup of the supercontinent Gondwana. The early isolation of Africa and Madagascar implies that the ostrich and extinct Madagascan elephant birds (Aepyornithidae) should be the oldest ratite lineages. We sequenced the mitochondrial genomes of two elephant birds and performed phylogenetic analyses, which revealed that these birds are the closest relatives of the New Zealand kiwi and are distant from the basal ratite lineage of ostriches. This unexpected result strongly contradicts continental vicariance and instead supports flighted dispersal in all major ratite lineages. We suggest that convergence toward gigantism and flightlessness was facilitated by early Tertiary expansion into the diurnal herbivory niche after the extinction of the dinosaurs.


Assuntos
Evolução Biológica , DNA/genética , Paleógnatas/classificação , Struthioniformes/classificação , Animais , Sequência de Bases , Voo Animal , Fósseis , Dados de Sequência Molecular , Nova Zelândia , Paleógnatas/genética , Filogenia , Struthioniformes/genética
11.
Integr Zool ; 9(2): 148-166, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24673760

RESUMO

In Australia, ratites (Aves: Palaeognathae) are represented in the extant fauna by the family Casuariidae with 1 species of emu Dromaius novaehollandiae and 1 cassowary Casuarius casuarius. The Australian fossil record reveals no other extinct ratite families but there are a number of other casuariid species. Most significant of these, due to its Oligo-Miocene age and because it is known from abundant material, is Emuarius gidju. Here, we describe additional material and confirm that the taxon had a temporal range of Late Oligocene to Middle Miocene (approximately 24-15 Ma). We reveal new morphological details, including notably that the species had relatively much smaller eyes than D. novaehollandiae, in addition to a less well-developed cursorial ability, as inferred from its pelvic limb. In these respects, Emuarius is similar to Casuarius and suggest that it was adapted to denser vegetation than the open woodlands and grasslands that characterise much of Australia today and to which D. novaehollandiae, with its large eyes and enhanced cursorial ability, is strongly adapted. Emuarius was compared to and found to be distinct from the poorly provenanced Australian fossil species C. lydekkeri. We conducted a phylogenetic analysis of morphological data that robustly shows that E. gidju is the sister taxon of Dromaius and together these taxa form a clade that is sister to Casuarius. This indicates that the evolution towards enhanced cursorality that characterises Dromaius took place after the divergence of the emu-cassowary lineages and was likely not the driving mechanism of this divergence. Comparisons between D. novaehollandiae and D. baudinianus revealed no qualitative skeletal differences and we suggest that the latter taxon is best considered to be an island dwarf that should be taxonomically recognized at a subspecific level only.


Assuntos
Evolução Biológica , Fósseis , Paleógnatas/anatomia & histologia , Paleógnatas/classificação , Filogenia , Animais , Austrália , Olho/anatomia & histologia , Membro Posterior/anatomia & histologia , Locomoção/fisiologia , Especificidade da Espécie
12.
PLoS One ; 8(12): e82668, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367537

RESUMO

The extinct moa of New Zealand included three families (Megalapterygidae; Dinornithidae; Emeidae) of flightless palaeognath bird, ranging in mass from <15 kg to >200 kg. They are perceived to have evolved extremely robust leg bones, yet current estimates of body mass have very wide confidence intervals. Without reliable estimators of mass, the extent to which dinornithid and emeid hindlimbs were more robust than modern species remains unclear. Using the convex hull volumetric-based method on CT-scanned skeletons, we estimate the mass of a female Dinornis robustus (Dinornithidae) at 196 kg (range 155-245 kg) and of a female Pachyornis australis (Emeidae) as 50 kg (range 33-68 kg). Finite element analysis of CT-scanned femora and tibiotarsi of two moa and six species of modern palaeognath showed that P. australis experienced the lowest values for stress under all loading conditions, confirming it to be highly robust. In contrast, stress values in the femur of D. robustus were similar to those of modern flightless birds, whereas the tibiotarsus experienced the highest level of stress of any palaeognath. We consider that these two families of Dinornithiformes diverged in their biomechanical responses to selection for robustness and mobility, and exaggerated hindlimb strength was not the only successful evolutionary pathway.


Assuntos
Ossos da Perna/anatomia & histologia , Paleógnatas/classificação , Animais , Evolução Biológica , Extinção Biológica , Feminino , Nova Zelândia , Paleógnatas/anatomia & histologia
13.
PLoS One ; 8(11): e80036, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244601

RESUMO

Three families of probe-foraging birds, Scolopacidae (sandpipers and snipes), Apterygidae (kiwi), and Threskiornithidae (ibises, including spoonbills) have independently evolved long, narrow bills containing clusters of vibration-sensitive mechanoreceptors (Herbst corpuscles) within pits in the bill-tip. These 'bill-tip organs' allow birds to detect buried or submerged prey via substrate-borne vibrations and/or interstitial pressure gradients. Shorebirds, kiwi and ibises are only distantly related, with the phylogenetic divide between kiwi and the other two taxa being particularly deep. We compared the bill-tip structure and associated somatosensory regions in the brains of kiwi and shorebirds to understand the degree of convergence of these systems between the two taxa. For comparison, we also included data from other taxa including waterfowl (Anatidae) and parrots (Psittaculidae and Cacatuidae), non-apterygid ratites, and other probe-foraging and non probe-foraging birds including non-scolopacid shorebirds (Charadriidae, Haematopodidae, Recurvirostridae and Sternidae). We show that the bill-tip organ structure was broadly similar between the Apterygidae and Scolopacidae, however some inter-specific variation was found in the number, shape and orientation of sensory pits between the two groups. Kiwi, scolopacid shorebirds, waterfowl and parrots all shared hypertrophy or near-hypertrophy of the principal sensory trigeminal nucleus. Hypertrophy of the nucleus basorostralis, however, occurred only in waterfowl, kiwi, three of the scolopacid species examined and a species of oystercatcher (Charadriiformes: Haematopodidae). Hypertrophy of the principal sensory trigeminal nucleus in kiwi, Scolopacidae, and other tactile specialists appears to have co-evolved alongside bill-tip specializations, whereas hypertrophy of nucleus basorostralis may be influenced to a greater extent by other sensory inputs. We suggest that similarities between kiwi and scolopacid bill-tip organs and associated somatosensory brain regions are likely a result of similar ecological selective pressures, with inter-specific variations reflecting finer-scale niche differentiation.


Assuntos
Bico/anatomia & histologia , Charadriiformes/anatomia & histologia , Mecanorreceptores/ultraestrutura , Paleógnatas/anatomia & histologia , Papagaios/anatomia & histologia , Núcleos do Trigêmeo/anatomia & histologia , Adaptação Fisiológica , Animais , Bico/diagnóstico por imagem , Bico/fisiologia , Evolução Biológica , Charadriiformes/classificação , Charadriiformes/fisiologia , Comportamento Alimentar/fisiologia , Mecanorreceptores/fisiologia , Paleógnatas/classificação , Paleógnatas/fisiologia , Papagaios/classificação , Papagaios/fisiologia , Filogenia , Radiografia , Especificidade da Espécie , Núcleos do Trigêmeo/diagnóstico por imagem , Núcleos do Trigêmeo/fisiologia , Vibração
14.
Syst Biol ; 62(1): 35-49, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22831877

RESUMO

Large-scale multilocus studies have become common in molecular phylogenetics, but the best way to interpret these studies when their results strongly conflict with prior information about phylogeny remains unclear. An example of such a conflict is provided by the ratites (the large flightless birds of southern land masses, including ostriches, emus, and rheas). Ratite monophyly is strongly supported by both morphological data and many earlier molecular studies and is used as a textbook example of vicariance biogeography. However, recent studies have indicated that ratites are not monophyletic; instead, the volant tinamous nest inside the ratites rather than forming their sister group within the avian superorder Palaeognathae. Large-scale studies can exhibit biases that reflect a number of factors, including limitations in the fit of the evolutionary models used for analyses and problems with sequence alignment, so the unexpected conclusion that ratites are not monophyletic needs to be rigorously evaluated. A rigorous approach to testing novel hypotheses generated by large-scale studies is to collect independent evidence (i.e., excluding the loci and/or traits used to generate the hypotheses). We used 40 nuclear loci not used in previous studies that investigated the relationship among ratites and tinamous. Our results strongly support the recent molecular studies, revealing that the deepest branch within Palaeognathae separates the ostrich from other members of the clade, rather than the traditional hypothesis that separates the tinamous from the ratites. To ensure these results reflected evolutionary history, we examined potential biases in types of loci used, heterotachy, alignment biases, and discordance between gene trees and the species tree. All analyses consistently supported nonmonophyly of the ratites and no confounding biases were identified. This confirmation that ratites are not monophyletic using independent evidence will hopefully stimulate further comparative research on paleognath development and genetics that might reveal the basis of the morphological convergence in these large, flightless birds.


Assuntos
Loci Gênicos/genética , Paleógnatas/classificação , Paleógnatas/genética , Filogenia , Animais , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA
15.
PLoS One ; 7(8): e42384, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22876319

RESUMO

The little spotted kiwi (Apteryx owenii) is a flightless ratite formerly found throughout New Zealand but now greatly reduced in distribution. Previous phylogeographic studies of the related brown kiwi (A. mantelli, A. rowi and A. australis), with which little spotted kiwi was once sympatric, revealed extremely high levels of genetic structuring, with mitochondrial DNA haplotypes often restricted to populations. We surveyed genetic variation throughout the present and pre-human range of little spotted kiwi by obtaining mitochondrial DNA sequences from contemporary and ancient samples. Little spotted kiwi and great spotted kiwi (A. haastii) formed a monophyletic clade sister to brown kiwi. Ancient samples of little spotted kiwi from the northern North Island, where it is now extinct, formed a lineage that was distinct from remaining little spotted kiwi and great spotted kiwi lineages, potentially indicating unrecognized taxonomic diversity. Overall, little spotted kiwi exhibited much lower levels of genetic diversity and structuring than brown kiwi, particularly through the South Island. Our results also indicate that little spotted kiwi (or at least hybrids involving this species) survived on the South Island mainland until more recently than previously thought.


Assuntos
Extinção Biológica , Paleógnatas/genética , Adenosina Trifosfatases/genética , Animais , Citocromos b/genética , DNA Mitocondrial/genética , Variação Genética , Haplótipos , Paleógnatas/classificação , Filogenia , Filogeografia , Alinhamento de Sequência
16.
PLoS One ; 7(6): e40025, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22768206

RESUMO

Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes) were New Zealand's largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave) on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus), and span from at least 6,368±31 until 694±30 (14)C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium) and tree fuchsia (Fuchsia excorticata). The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus) forest to tussock (Chionochloa) grassland). Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates), probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation.


Assuntos
Ecossistema , Extinção Biológica , Fósseis , Paleógnatas/classificação , Animais , Cavernas , DNA de Plantas/genética , Humanos , Nova Zelândia , Paleógnatas/genética , Plantas/classificação , Plantas/genética , Pólen/genética , Datação Radiométrica , Especificidade da Espécie
17.
BMC Evol Biol ; 10: 387, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21156082

RESUMO

BACKGROUND: Kiwi is a highly distinctive, flightless and endangered ratite bird endemic to New Zealand. To understand the patterns of molecular evolution of the nuclear protein-coding genes in brown kiwi (Apteryx australis mantelli) and to determine the timescale of avian history we sequenced a transcriptome obtained from a kiwi embryo using next generation sequencing methods. We then assembled the conserved protein-coding regions using the chicken proteome as a scaffold. RESULTS: Using 1,543 conserved protein coding genes we estimated the neutral evolutionary divergence between the kiwi and chicken to be ~45%, which is approximately equal to the divergence computed for the human-mouse pair using the same set of genes. A large fraction of genes was found to be under high selective constraint, as most of the expressed genes appeared to be involved in developmental gene regulation. Our study suggests a significant relationship between gene expression levels and protein evolution. Using sequences from over 700 nuclear genes we estimated the divergence between the two basal avian groups, Palaeognathae and Neognathae to be 132 million years, which is consistent with previous studies using mitochondrial genes. CONCLUSIONS: The results of this investigation revealed patterns of mutation and purifying selection in conserved protein coding regions in birds. Furthermore this study suggests a relatively cost-effective way of obtaining a glimpse into the fundamental molecular evolutionary attributes of a genome, particularly when no closely related genomic sequence is available.


Assuntos
Evolução Molecular , Perfilação da Expressão Gênica , Paleógnatas/genética , Animais , Núcleo Celular/genética , Sequência Conservada , Dosagem de Genes , Biblioteca Gênica , Humanos , Masculino , Camundongos , Nova Zelândia , Paleógnatas/classificação , Seleção Genética , Análise de Sequência de DNA
18.
Zoology (Jena) ; 113(6): 334-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21115291

RESUMO

The Tinamidae comprise exclusively Neotropical palaegnathous birds, with homogeneous body morphology and no sexual dimorphism. The goal of this work was to explore the variation in skull morphology between taxa and its possible correspondence with features such as diet or gender using geometric morphometric tools. Eleven landmarks were analyzed in 53 skulls of 4 genera that inhabit grasslands: Nothoprocta, Eudromia, Nothura and Rhynchotus. Intrageneric and intergeneric variability was analyzed. The genera studied here can be distinguished based on the geometric shape of their skull, with prenarial region length and neurocranium shape as the most outstanding features. In the genus Eudromia, males and females could be differentiated, while in the genus Nothoprocta, the species differentiated according to their trophic habits. This study allows establishing that genera and, in some cases, the gender of the Tinamidae can be differentiated based on cranial shape.


Assuntos
Cefalometria , Paleógnatas/anatomia & histologia , Crânio/anatomia & histologia , Animais , Biometria , Feminino , Masculino , Paleógnatas/classificação , Filogenia , Caracteres Sexuais
19.
Proc Natl Acad Sci U S A ; 107(37): 16201-6, 2010 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-20805485

RESUMO

New Zealand's extinct flightless moa radiated rapidly into a large number of morphologically diverse species, which produced an equally large range of egg morphologies. The exact number of moa species, as well as the characteristics of the eggs they laid, remains contentious. Moreover, like most extinct species, we understand little about their nesting and incubation habits. We used a modified ancient DNA extraction procedure to recover exogenous mitochondrial and nuclear DNA from the inside and outside surfaces of moa eggs. We used sequences from the inside of 69 eggshells to directly assign these remains to seven of the 10 currently recognized moa species. In addition we were able to assign, to the species level, six of the rare reconstructed "whole" eggs. These molecular results enabled us to identify two distinct lineages within the genus Euryapteryx. Members of these lineages differed in eggshell thickness, with one lineage being characterized by a relatively thin eggshell. Unexpectedly, several thin-shelled eggs were also shown to belong to the heaviest moa of the genera Dinornis, Euryapteryx and Emeus, making these, to our knowledge, the most fragile of all avian eggs measured to date. Moreover, sex-specific DNA recovered from the outer surfaces of eggshells belonging to species of Dinornis and Euryapteryx suggest that these very thin eggs were likely to have been incubated by the lighter males. The thin nature of the eggshells of these larger species of moa, even if incubated by the male, suggests that egg breakage in these species would have been common if the typical contact method of avian egg incubation was used.


Assuntos
DNA/genética , Extinção Biológica , Comportamento de Nidação , Paleógnatas/genética , Filogenia , Animais , Sequência de Bases , Casca de Ovo/química , Casca de Ovo/metabolismo , Feminino , Masculino , Nova Zelândia , Paleógnatas/anatomia & histologia , Paleógnatas/classificação , Paleógnatas/fisiologia
20.
Proc Natl Acad Sci U S A ; 106(49): 20646-51, 2009 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-19923428

RESUMO

The ratite moa (Aves: Dinornithiformes) were a speciose group of massive graviportal avian herbivores that dominated the New Zealand (NZ) ecosystem until their extinction approximately 600 years ago. The phylogeny and evolutionary history of this morphologically diverse order has remained controversial since their initial description in 1839. We synthesize mitochondrial phylogenetic information from 263 subfossil moa specimens from across NZ with morphological, ecological, and new geological data to create the first comprehensive phylogeny, taxonomy, and evolutionary timeframe for all of the species of an extinct order. We also present an important new geological/paleogeographical model of late Cenozoic NZ, which suggests that terrestrial biota on the North and South Island landmasses were isolated for most of the past 20-30 Ma. The data reveal that the patterns of genetic diversity within and between different moa clades reflect a complex history following a major marine transgression in the Oligocene, affected by marine barriers, tectonic activity, and glacial cycles. Surprisingly, the remarkable morphological radiation of moa appears to have occurred much more recently than previous early Miocene (ca. 15 Ma) estimates, and was coincident with the accelerated uplift of the Southern Alps just ca. 5-8.5 Ma. Together with recent fossil evidence, these data suggest that the recent evolutionary history of nearly all of the iconic NZ terrestrial biota occurred principally on just the South Island.


Assuntos
Evolução Biológica , Extinção Biológica , Geografia , Paleógnatas/genética , Paleontologia , Animais , Biodiversidade , Calibragem , DNA Mitocondrial/genética , Especiação Genética , Dados de Sequência Molecular , Nova Zelândia , Paleógnatas/classificação , Filogenia , Fatores de Tempo
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