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1.
Chun‐Lei Xiang Hong‐Jin Dong Sven Landrein Fei Zhao Wen‐Bin Yu Douglas E. Soltis Pamela S. Soltis Anders Backlund Hua‐Feng Wang De‐Zhu Li Hua Peng 《植物分类学报:英文版》2020,58(2):103-117
Phylogenetic relationships in Dipsacales have long been a major challenge. Although considerable progress has been made during the past two decades, questions remain; the uncertain systematic positions of Heptacodium, Triplostegia, and Zabelia, in particular, impede our understanding of Dipsacales evolution. Here we use 75 complete plastomic sequences to reconstruct the phylogeny of Dipsacales, of which 28 were newly generated. Two primary clades were recovered that form the phylogenetic backbone of Dipsacales. Seven of the primary clades correspond to the recognized families Adoxaceae, Caprifoliaceae s. str., Diervillaceae, Dipsacaceae, Linnaeaceae, Morinaceae, and Valerianaceae, and one corresponds to Zabelia, which was found to be the closest relative of Morinaceae in all analyses. Additionally, our results, with greatly increased confidence in most branches, show that Heptacodium and Triplostegia are members of Caprifoliaceae s. str. and Dipsacaceae, respectively. The results of our study indicate that the complete plastomic sequences provide a fully‐resolved and well‐supported representation of the phylogenetic relationships within Dipsacales. 相似文献
2.
3.
Weigela and three species of Diervilla were inferred from nucleotide sequence variation in the internal transcribed spacer (ITS) regions of 18-26S nuclear ribosomal
DNA. Phylogenetic trees were obtained using parsimony, distance, and maximum likelihood methods. The ITS phylogenies did not
support the monophyly of Weigela, which comprises three major clades. The first clade includes a single species, W. middendorffiana, which is more closely related with American genus, Diervilla. The second clade consisted of a single species, W. maximowiczii, but its relationship to other Weigela species is equivocal. The third one is a strongly supported core clade which contains the remaining Weigela species. Within the core group, W. hortensis exhibits the most distinct ITS sequence type. The hybrid origin of the species from the putative parents, W. florida and W. subsessilis, is not supported. The ITS sequence evidence favors the taxonomic hypothesis proposed by Nakai who recognized four distinct
evolutionary lines (Diervilla, Macrodiervilla, Weigelastrum and Weigela). However, recognition of the two sections, Calysphyrum and Weigela was not supported in the ITS phylogenies. Substantial morphological differences between Diervilla and Weigela middendorffiana do not support the morphological stasis concept which has been considered as a general evolutionary mode among the Asian
and North American disjunct taxa.
Received 27 July 1998/ Accepted in revised form 7 July 1999 相似文献
4.
Background
Holcoglossum is a small orchid genus of 12 species ranging from SW China to Thailand and NE India. Although molecular and morphological analyses have been performed to establish the phylogenetic relationships within this genus, the interspecific relations and its relations with allied genera, such as Rhynchostylis, Aerides and Vanda, remain unclear.Methodology/Principal Findings
In addition to morphological analysis, maximum parsimony, maximum likelihood, and Bayesian inference analyses were performed based on fragments of the nuclear ITS and chloroplast trnL-F and matK genes of 31 taxa (15 Holcoglossum, 14 Aeridinae, 2 outgroups) representing all major clades of the Holcoglossum alliance. The results suggest that Holcoglossum is triphyletic, comprising three clades: the Holcoglossum clade, its sister clade, and a distant clade more closely related to Rhynchostylis, Aerides, and Vanda than to the Holcoglossum clade. The Holcoglossum clade is further divided into three subclades; the genetic distances between these three subclades also support this delimitation. The molecular conclusion is consistent with their distinct morphological characters.Conclusions
We propose that the latter two clades comprise two new genera, Paraholcoglossum and Tsiorchis, and Holcoglossum clade divides into three sections. In addition, a new section, Holcoglossum sect. Nujiangensia, and a new species, Holcoglossum linearifolium, are proposed. Some new combinations are made, and a new scheme is provided for the classification of all species of Holcoglossum, Paraholcoglossum, and Tsiorchis. 相似文献5.
6.
Michelle Moore Massamba Sylla Laura Goss Marion Warigia Burugu Rosemary Sang Luna W. Kamau Eucharia Unoma Kenya Chris Bosio Maria de Lourdes Munoz Maria Sharakova William Cormack Black 《PLoS neglected tropical diseases》2013,7(4)
Background
Aedes aegypti is the primary global vector to humans of yellow fever and dengue flaviviruses. Over the past 50 years, many population genetic studies have documented large genetic differences among global populations of this species. These studies initially used morphological polymorphisms, followed later by allozymes, and most recently various molecular genetic markers including microsatellites and mitochondrial markers. In particular, since 2000, fourteen publications and four unpublished datasets have used sequence data from the NADH dehydrogenase subunit 4 mitochondrial gene to compare Ae. aegypti collections and collectively 95 unique mtDNA haplotypes have been found. Phylogenetic analyses in these many studies consistently resolved two clades but no comprehensive study of mtDNA haplotypes have been made in Africa, the continent in which the species originated.Methods and Findings
ND4 haplotypes were sequenced in 426 Ae. aegypti s.l. from Senegal, West Africa and Kenya, East Africa. In Senegal 15 and in Kenya 7 new haplotypes were discovered. When added to the 95 published haplotypes and including 6 African Aedes species as outgroups, phylogenetic analyses showed that all but one Senegal haplotype occurred in a basal clade while most East African haplotypes occurred in a second clade arising from the basal clade. Globally distributed haplotypes occurred in both clades demonstrating that populations outside Africa consist of mixtures of mosquitoes from both clades.Conclusions
Populations of Ae. aegypti outside Africa consist of mosquitoes arising from one of two ancestral clades. One clade is basal and primarily associated with West Africa while the second arises from the first and contains primarily mosquitoes from East Africa 相似文献7.
Background
Because they represent the earliest divergences of the Chlorophyta, the morphologically diverse unicellular green algae making up the prasinophytes hold the key to understanding the nature of the first viridiplants and the evolutionary patterns that accompanied the radiation of chlorophytes. Nuclear-encoded 18S rDNA phylogenies unveiled nine prasinophyte clades (clades I through IX) but their branching order is still uncertain. We present here the newly sequenced chloroplast genomes of Nephroselmis astigmatica (clade III) and of five picoplanktonic species from clade VI (Prasinococcus sp. CCMP 1194, Prasinophyceae sp. MBIC 106222 and Prasinoderma coloniale) and clade VII (Picocystis salinarum and Prasinophyceae sp. CCMP 1205). These chloroplast DNAs (cpDNAs) were compared with those of the six previously sampled prasinophytes (clades I, II, III and V) in order to gain information both on the relationships among prasinophyte lineages and on chloroplast genome evolution.Results
Varying from 64.3 to 85.6 kb in size and encoding 100 to 115 conserved genes, the cpDNAs of the newly investigated picoplanktonic species are substantially smaller than those observed for larger-size prasinophytes, are economically packed and contain a reduced gene content. Although the Nephroselmis and Picocystis cpDNAs feature a large inverted repeat encoding the rRNA operon, gene partitioning among the single copy regions is remarkably different. Unexpectedly, we found that all three species from clade VI (Prasinococcales) harbor chloroplast genes not previously documented for chlorophytes (ndhJ, rbcR, rpl21, rps15, rps16 and ycf66) and that Picocystis contains a trans-spliced group II intron. The phylogenies inferred from cpDNA-encoded proteins are essentially congruent with 18S rDNA trees, resolving with robust support all six examined prasinophyte lineages, with the exception of the Pycnococcaceae.Conclusions
Our results underscore the high variability in genome architecture among prasinophyte lineages, highlighting the strong pressure to maintain a small and compact chloroplast genome in picoplanktonic species. The unique set of six chloroplast genes found in the Prasinococcales supports the ancestral status of this lineage within the prasinophytes. The widely diverging traits uncovered for the clade-VII members (Picocystis and Prasinophyceae sp. CCMP 1205) are consistent with their resolution as separate lineages in the chloroplast phylogeny. 相似文献8.
Timoth��e Le P��chon Jean-Yves Dubuisson Thomas Haevermans Corinne Cruaud Arnaud Couloux Luc D. B. Gigord 《Annals of botany》2010,106(2):343-357
Background and Aims
In the Mascarenes, a young oceanic archipelago composed of three main islands, the Dombeyoideae (Malvaceae) have diversified extensively with a high endemism rate. With the exception of the genus Trochetia, Mascarene Dombeyoideae are described as dioecious whereas Malagasy and African species are considered to be monocline, species with individuals bearing hermaphrodite/perfect flowers. In this study, the phylogenetic relationships were reconstructed to clarify the taxonomy, understand the phylogeographic pattern of relationships and infer the evolution of the breeding systems for the Mascarenes Dombeyoideae.Methods
Parsimony and Bayesian analysis of four DNA markers (ITS, rpl16 intron and two intergenic spacers trnQ-rsp16 and psbM-trnD) was used. The molecular matrix comprised 2985 characters and 48 taxa. The Bayesian phylogeny was used to infer phylogeographical hypotheses and the evolution of breeding systems.Key Results
Parsimony and Bayesian trees produced similar results. The Dombeyoideae from the Mascarenes are polyphyletic and distributed among four clades. Species of Dombeya, Trochetia and Ruizia are nested in the same clade, which implies the paraphyly of Dombeya. Additionally, it is shown that each of the four clades has an independent Malagasy origin. Two adaptive radiation events have occurred within two endemic lineages of the Mascarenes. The polyphyly of the Mascarene Dombeyoideae suggests at least three independent acquisitions of dioecy.Conclusions
This molecular phylogeny highlights the taxonomic issues within the Dombeyoideae. Indeed, the limits and distinctions of the genera Dombeya, Trochetia and Ruizia should be reconsidered. The close phylogeographic relationships between the flora of the Mascarenes and Madagascar are confirmed. Despite their independent origins and a distinct evolutionary history, each endemic clade has developed a different breeding systems (dioecy) compared with the Malagasy Dombeyoideae. Sex separation appears as an evolutionary convergence and may be the consequence of selective pressures particular to insular environments. 相似文献9.
Background and Aims
The subgenus Ceratotropis in the genus Vigna is widely distributed from the Himalayan highlands to South, Southeast and East Asia. However, the interspecific and geographical relationships of its members are poorly understood. This study investigates the phylogeny and biogeography of the subgenus Ceratotropis using chloroplast DNA sequence data.Methods
Sequence data from four intergenic spacer regions (petA-psbJ, psbD-trnT, trnT-trnE and trnT-trnL) of chloroplast DNA, alone and in combination, were analysed using Bayesian and parsimony methods. Divergence times for major clades were estimated with penalized likelihood. Character evolution was examined by means of parsimony optimization and MacClade.Key Results
Parsimony and Bayesian phylogenetic analyses on the combined data demonstrated well-resolved species relationships in which 18 Vigna species were divided into two major geographical clades: the East Asia–Southeast Asian clade and the Indian subcontinent clade. Within these two clades, three well-supported eco-geographical groups, temperate and subtropical (the East Asia–Southeast Asian clade) and tropical (the Indian subcontinent clade), are recognized. The temperate group consists of V. minima, V. nepalensis and V. angularis. The subtropical group comprises the V. nakashimae–V. riukiuensis–V. minima subgroup and the V. hirtella–V. exilis–V. umbellata subgroup. The tropical group contains two subgroups: the V. trinervia–V. reflexo-pilosa–V. trilobata subgroup and the V. mungo–V. grandiflora subgroup. An evolutionary rate analysis estimated the divergence time between the East Asia–Southeast Asia clade and the Indian subcontinent clade as 3·62 ± 0·3 million years, and that between the temperate and subtropical groups as 2·0 ± 0·2 million years.Conclusions
The findings provide an improved understanding of the interspecific relationships, and ecological and geographical phylogenetic structure of the subgenus Ceratotropis. The quaternary diversification of the subgenus Ceratotropis implicates its geographical dispersal in the south-eastern part of Asia involving adaptation to climatic condition after the collision of the Indian subcontinent with the Asian plate. The phylogenetic results indicate that the epigeal germination is plesiomorphic, and the germination type evolved independently multiple times in this subgenus, implying its limited taxonomic utility. 相似文献10.
Paauw A Caspers MP Schuren FH Leverstein-van Hall MA Delétoile A Montijn RC Verhoef J Fluit AC 《PloS one》2008,3(8):e3018
Background
Isolates of the Enterobacter cloacae complex have been increasingly isolated as nosocomial pathogens, but phenotypic identification of the E. cloacae complex is unreliable and irreproducible. Identification of species based on currently available genotyping tools is already superior to phenotypic identification, but the taxonomy of isolates belonging to this complex is cumbersome.Methodology/Principal Findings
This study shows that multilocus sequence analysis and comparative genomic hybridization based on a mixed genome array is a powerful method for studying species assignment within the E. cloacae complex. The E. cloacae complex is shown to be evolutionarily divided into two clades that are genetically distinct from each other. The younger first clade is genetically more homogenous, contains the Enterobacter hormaechei species and is the most frequently cultured Enterobacter species in hospitals. The second and older clade consists of several (sub)species that are genetically more heterogonous. Genetic markers were identified that could discriminate between the two clades and cluster 1.Conclusions/Significance
Based on genomic differences it is concluded that some previously defined (clonal and heterogenic) (sub)species of the E. cloacae complex have to be redefined because of disagreements with known or proposed nomenclature. However, further improved identification of the redefined species will be possible based on novel markers presented here. 相似文献11.
Background and Aims
The taxonomic complexity of Crataegus (hawthorn; Rosaceae, Maleae), especially in North America, has been attributed by some to hybridization in combination with gametophytic apomixis and polyploidization, whereas others have considered the roles of hybridization and apomixis to be minimal. Study of the chemical composition and therapeutic value of hawthorn extracts requires reproducible differentiation of entities that may be difficult to distinguish by morphology alone. This study sought to address this by using the nuclear ribosomal spacer region ITS2 as a supplementary DNA barcode; however, a lack of success prompted an investigation to discover why this locus gave unsatisfactory results.Methods
ITS2 was extensively cloned so as to document inter- and intraindividual variation in this locus, using hawthorns of western North America where the genus Crataegus is represented by only two widely divergent groups, the red-fruited section Coccineae and the black-fruited section Douglasia. Additional sequence data from selected loci on the plastid genome were obtained to enhance further the interpretation of the ITS2 results.Key Results
In the ITS2 gene tree, ribotypes from western North American hawthorns are found in two clades. Ribotypes from diploid members of section Douglasia occur in one clade (with representatives of the east-Asian section Sanguineae). The other clade comprises those from diploid and polyploid members of section Coccineae. Both clades contribute ribotypes to polyploid Douglasia. Data from four plastid-derived intergenic spacers demonstrate the maternal parentage of these allopolyploids.Conclusions
Repeated hybridization between species of section Douglasia and western North American members of section Coccineae involving the fertilization of unreduced female gametes explains the observed distribution of ribotypes and accounts for the phenetic intermediacy of many members of section Douglasia. 相似文献12.
Sara Melito Angela Sias Giacomo L. Petretto Mario Chessa Giorgio Pintore Andrea Porceddu 《PloS one》2013,8(11)
Background
Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia.Methods
H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA.Key results
The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity.Conclusions
The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil. 相似文献13.
Marie Foug��re-Danezan Patrick S. Herendeen St��phan Maumont Anne Bruneau 《Annals of botany》2010,105(2):311-325
Background and Aims
Previous molecular phylogenetic studies disagree with the informal generic-level taxonomic groups based on morphology. In this study morphological characters in the caesalpinioid clade Detarieae are evaluated within a phylogenetic framework as a means of better understanding phylogenetic relationships and morphological evolution.Methods
Morphological characters were observed and scored for representative species of Detarieae focusing on the resin-producing genera. Phylogenetic analyses were carried out with morphological characters alone and then combined with DNA sequences.Key Results
Despite a high level of homoplasy, morphological data support several clades corresponding to those recovered in molecular phylogenetic analyses. The more strongly supported clades are each defined by at least one morphological synapomorphy. Several characters (e.g. apetaly) previously used to define informal generic groups evolved several times independently, leading to the differences observed with the molecular phylogenetic analyses. Although floral evolution is complex in Detarieae some patterns are recovered.Conclusions
New informal taxonomic groupings are proposed based on the present findings. Floral evolution in the diverse Detarieae clade is characterized by a repeated tendency toward zygomorphy through the reduction of lateral petals and toward complete loss of petals.Key words: Caesalpinioideae, Detarieae, floral evolution, Leguminosae, morphology, phylogeny, resins, taxonomy 相似文献14.
Jos C. Mieog Jeanine L. Olsen Ray Berkelmans Silvia A. Bleuler-Martinez Bette L. Willis Madeleine J. H. van Oppen 《PloS one》2009,4(7)
Background
Reef-building corals live in symbiosis with a diverse range of dinoflagellate algae (genus Symbiodinium) that differentially influence the fitness of the coral holobiont. The comparative role of symbiont type in holobiont fitness in relation to host genotype or the environment, however, is largely unknown. We addressed this knowledge gap by manipulating host-symbiont combinations and comparing growth, survival and thermal tolerance among the resultant holobionts in different environments.Methodology/Principal Findings
Offspring of the coral, Acropora millepora, from two thermally contrasting locations, were experimentally infected with one of six Symbiodinium types, which spanned three phylogenetic clades (A, C and D), and then outplanted to the two parental field locations (central and southern inshore Great Barrier Reef, Australia). Growth and survival of juvenile corals were monitored for 31–35 weeks, after which their thermo-tolerance was experimentally assessed. Our results showed that: (1) Symbiodinium type was the most important predictor of holobiont fitness, as measured by growth, survival, and thermo-tolerance; (2) growth and survival, but not heat-tolerance, were also affected by local environmental conditions; and (3) host population had little to no effect on holobiont fitness. Furthermore, coral-algal associations were established with symbiont types belonging to clades A, C and D, but three out of four symbiont types belonging to clade C failed to establish a symbiosis. Associations with clade A had the lowest fitness and were unstable in the field. Lastly, Symbiodinium types C1 and D were found to be relatively thermo-tolerant, with type D conferring the highest tolerance in A. millepora.Conclusions/Significance
These results highlight the complex interactions that occur between the coral host, the algal symbiont, and the environment to shape the fitness of the coral holobiont. An improved understanding of the factors affecting coral holobiont fitness will assist in predicting the responses of corals to global climate change. 相似文献15.
Unrestricted quality of seeds in European broad-leaved tree species growing at the cold boundary of their distribution 总被引:1,自引:0,他引:1
Background and Aims
The low-temperature range limit of tree species may be determined by their ability to produce and disperse viable seeds. Biological processes such as flowering, pollen transfer, pollen tube growth, fertilization, embryogenesis and seed maturation are expected to be affected by cold temperatures. The aim of this study was to assess the quality of seeds of nine broad-leaved tree species close to their elevational limit.Methods
We studied nine, mostly widely distributed, European broad-leaved tree species in the genera Acer, Fagus, Fraxinus, Ilex, Laburnum, Quercus, Sorbus and Tilia. For each species, seeds were collected from stands close to optimal growth conditions (low elevation) and from marginal stands (highest elevation), replicated in two regions in the Swiss Alps. Measurements included seed weight, seed size, storage tissue quality, seed viability and germination success.Key Results
All species examined produced a lot of viable seeds at their current high-elevation range limit during a summer ranked ‘normal’ by long-term temperature records. Low- and high-elevation seed sources showed hardly any trait differences. The concentration of non-structural carbohydrates tended to be higher at high elevation. Additionally, in one species, Sorbus aucuparia, all measured traits showed significantly higher seed quality in high-elevation seed sources.Conclusions
For the broad-leaved tree taxa studied, the results are not in agreement with the hypothesis of reduced quality of seeds in trees at their high-elevation range limits. Under the current climatic conditions, seed quality does not constitute a serious constraint in the reproduction of these broad-leaved tree species at their high-elevation limit. 相似文献16.
Mookkan Prabakaran Sonja Leyrer Fang He Sebastian Auer Subaschandrabose R. Kumar Kathrin Kindsmueller Nutan Mytle Joerg Schneider Stephen Lockhart Jimmy Kwang 《PloS one》2014,9(9)
Background
The rapid evolution of new sublineages of H5N1 influenza poses the greatest challenge in control of H5N1 infection by currently existing vaccines. To overcome this, an MVAtor vector expressing three H5HA antigens A/Vietnam/1203/04, A/Indonesia/669/06 and A/Anhui/01/05 (MVAtor-tri-HA vector) was developed to elicit broad cross-protection against diverse clades by covering amino acid variations in the major neutralizing epitopes of HA among H5N1 subtypes.Methods
BALB/c mice and guinea pigs were immunized i.m. with 8×107 TCID50/animal of MVAtor-tri-HA vector. The immunogenicity and cross-protective immunity of the MVAtor-tri-HA vector was evaluated against diverse clades of H5N1 strains.Results
The results showed that mice immunized with MVAtor-tri-HA vector induced robust cross-neutralizing immunity to diverse H5N1 clades. In addition, the MVAtor-tri-HA vector completely protected against 10 MLD50 of a divergent clade of H5N1 infection (clade 7). Importantly, the serological surveillance of post-vaccinated guinea pig sera demonstrated that MVAtor-tri-HA vector was able to elicit strong cross-clade neutralizing immunity against twenty different H5N1 strains from six clades that emerged between 1997 and 2012.Conclusions
The present findings revealed that incorporation of carefully selected HA genes from divergent H5N1 strains within a single vector could be an effective approach in developing a vaccine with broad coverage to prevent infection during a pandemic situation. 相似文献17.
Sequences of the chloroplast trnL-F region and 3(') end ndhF gene were used to elucidate phylogenetic relationships and the delimitation of families within Dipsacales s.l. Parsimony analyses of individual and combined data were conducted using maximum parsimony method. The most parsimonious tree based on combined trnL-F and 3(') end ndhF data set recognizes seven major clades of Dipsacales s.l. with the following relationships: Apiales (Adoxaceae ((Diervillaceae, Caprifoliaceae s.str.) (Linnaeaceae (Morinaceae (Dipsacaceae, Valerianaceae))))). Both Sambucus and Viburnum have close relationships with Adoxaceae, supporting their inclusion in this family. Caprifoliaceae s.l. (excluding Sambucus and Viburnum) is polyphyletic, and comprises three clades or families, i.e., Linnaeaceae (Abelia, Dipelta, Kolkwitzia, and Linnaea), Diervillaceae (Weigela and Diervilla) and Caprifoliaceae s.str. (Heptacodium, Leycesteria, Lonicera, Symphoricarpos, and Triosteum). This study focuses on the systematic position of Heptacodium, Triplostegia, and Morinaceae; and suggests that Heptacodium is closely related to the other Caprifoliaceae s.str.; Triplostegia is a sister to Dipsacaceae; Morinaceae, which has an affinity with Dipsacaceae, is possibly a sister group with Dipsacaceae-Valerianaceae clade. Our results are highly congruent with those of and. 相似文献
18.
Whitlock JA 《PloS one》2011,6(4):e18304
Background
As gigantic herbivores, sauropod dinosaurs were among the most important members of Mesozoic communities. Understanding their ecology is fundamental to developing a complete picture of Jurassic and Cretaceous food webs. One group of sauropods in particular, Diplodocoidea, has long been a source of debate with regard to what and how they ate. Because of their long lineage duration (Late Jurassic-Late Cretaceous) and cosmopolitan distribution, diplodocoids formed important parts of multiple ecosystems. Additionally, fortuitous preservation of a large proportion of cranial elements makes them an ideal clade in which to examine feeding behavior.Methodology/Principal Findings
Hypotheses of various browsing behaviors (selective and nonselective browsing at ground-height, mid-height, or in the upper canopy) were examined using snout shape (square vs. round) and dental microwear. The square snouts, large proportion of pits, and fine subparallel scratches in Apatosaurus, Diplodocus, Nigersaurus, and Rebbachisaurus suggest ground-height nonselective browsing; the narrow snouts of Dicraeosaurus, Suuwassea, and Tornieria and the coarse scratches and gouges on the teeth of Dicraeosaurus suggest mid-height selective browsing in those taxa. Comparison with outgroups (Camarasaurus and Brachiosaurus) reinforces the inferences of ground- and mid-height browsing and the existence of both non-selective and selective browsing behaviors in diplodocoids.Conclusions/Significance
These results reaffirm previous work suggesting the presence of diverse feeding strategies in sauropods and provide solid evidence for two different feeding behaviors in Diplodocoidea. These feeding behaviors can subsequently be tied to paleoecology, such that non-selective, ground-height behaviors are restricted to open, savanna-type environments. Selective browsing behaviors are known from multiple sauropod clades and were practiced in multiple environments. 相似文献19.
20.
Renee E. Tuckett David J. Merritt Paula J. Rudall Fiona Hay Stephen D. Hopper Carol C. Baskin Jerry M. Baskin Julia Tratt Kingsley W. Dixon 《Annals of botany》2010,105(6):1053-1061