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1.
Central to issues surrounding the origin of euprimates, affinities of Paleocene Carpolestidae have been controversial. Carpolestids have been classified as plesiadapoid primates, tarsiiform euprimates, dermopterans, or the sister taxon of euprimates to the exclusion of other plesiadapiforms, based exclusively on dental or postcranial data. Newly discovered crania of Carpolestes simpsoni from the latest Paleocene of the Clarks Fork Basin, Wyoming, are the first described for the family Carpolestidae. The two best preserved skulls were studied using ultra high-resolution X-ray computed tomography. Comparison of these specimens to those of other stem primates (Plesiadapiformes) demonstrates that the diversity of cranial morphology in this group is greater than previously thought. Carpolestes differs from euprimates and is similar to other plesiadapiforms (Ignacius and Plesiadapis) in lacking a postorbital bar and having a relatively long rostrum. Carpolestes is similar to fossil euprimates and Plesiadapis in having a bullar morphology consistent with a petrosal origin, and differs from Ignacius, in which the bulla is composed of the entotympanic. Carpolestes differs from primitive euprimates and all other known plesiadapiforms in possessing a two-chambered auditory bulla, similar to that of modern Tarsius. However, Carpolestes had an internal carotid artery (ICA) that took a transpromontorial route from a posteromedially positioned posterior carotid foramen (pcf), unlike Tarsius, in which this artery takes a perbullar route from an anterolaterally positioned pcf. Carpolestes has clear grooves on the promontorium for both the promontorial and stapedial arteries, indicating that it had an unreduced internal carotid circulation, similar to that of early euprimates. Carpolestes differs from primitive euprimates and some specimens of Ignacius in not having bony tubes surrounding the branches of the ICA. Cladistic analysis of cranial data fails to support a close relationship of Carpolestidae to either tarsiiform euprimates or extant Dermoptera, but suggests a close relationship between Carpolestidae, Plesiadapidae, and Euprimates. 相似文献
2.
Doug M. Boyer Loïc Costeur Yaron Lipman 《American journal of physical anthropology》2012,149(3):329-346
Plesiadapids are extinct relatives of extant euarchontans (primates, dermopterans, and scandentians), which lived in North America and Europe during the Paleocene and Early Eocene. The only genus of plesiadapid whose species are absent from Paleocene strata is Platychoerops. Further, Platychoerops is the only group found in sediments post‐dating the Paleocene‐Eocene boundary (PEB) by a substantial period of time based on large samples. It is also substantially different from other plesiadapids in dental features thought to reflect ecology. Its evolution has been linked to the rapid global climate change and faunal turnover marking the PEB. Platychoerops and Plesiadapis tricuspidens have been reconstructed as members of a single lineage by some authors. We describe a specimen (right p3‐m3) that we attribute to a new species, Platychoeropsantiquus, from the unequivocally Paleocene (MP6) Mouras Quarry of Mont de Berru, France. It has strong morphological affinities to Platychoerops daubrei yet co‐occurs with many specimens of Plesiadapis tricuspidens, as well as the plesiadapid Chiromyoides campanicus. The existence of a species of Platychoerops prior to the PEB decouples the evolution of Platychoerops from the climate change and faunal turnover event associated with the PEB. Furthermore, the co‐occurrence of Platychoerops with P. tricuspidens refutes the idea of a single lineage for these taxa. Instead, Platychoerops may be more closely related to North American Plesiadapis cookei (a previous alternate hypothesis). We suggest character displacement in a Paleocene immigrant population of P. cookei resulting from competition with sympatric P. tricuspidens, as a likely scenario for the evolution of Platychoerops. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
3.
Based on a cladistic analysis of 45 morphological (craniodental) and 46 binary allozyme characters, previous systematic treatments of the African murid tribe, Otomyini (laminate-toothed rats), are reviewed. Cladistic analysis of the craniodental data, involving eight outgroup taxa, confirmed the monophyly of the Otomyini, and suggested Pelomys to represent the sister genus of the Otomyini. Craniodental synapomorphies provided strong support for certain basal relationships among Otomyini rodents, reinforcing available palaeontological evidence. However, poor statistical (Bremer decay index) support was obtained for terminal relationships. The data presented revealed a 'mesic clade' of southern and eastern African species, with Otomys sloggetti basal to this group. The arid-adapted, southern Africa-endemic species, Parotomys littledalei , P. brantsii and O. unisulcatus , were all placed basal to the 'mesic clade', but did not form a separate 'arid clade', as suggested by earlier biochemical studies. Two allozyme synapomorphies supported the existence of the 'mesic clade', separate from arid-adapted southern African species. A strict cladistic interpretation of the present data did not support the existence of two genera in the tribe, and the two species of Parotomys (whistling rats) should be transferred to Otomys . At the species level, specific identity of O. lacustris and O. barbouri , distinct from O. anchietae , was supported by several autapomorphies, and O. tropicalis burtoni was shown to be included in O. angoniensis rather than O. tropicalis , extending the range of the former species into West Africa. 相似文献
4.
The Picrodontidae is a unique family of early Tertiary Primates. Previous discussions of picrodontid dental morphology centered on limited samples. This analysis uses a much larger sample to more completely describe the posterior dentition of Picrodus silberlingi. A diagnostic feature of the members of this family is the presence of a highly modified and enlarged anterior cheek tooth. This tooth, generally regarded as a first molar, displays the highest degree of discrete variation. The remaining molars, although unusual for plesiadapiforms, are less variable in both metric and nonmetric characteristics. The morphology of these cheek teeth is analogous to that of the nectar and pollen eating Glossophagine bats and suggests that the picrodontids possessed a similar dietary adaptation. The results of this analysis support the retention of P. silberlingi as a single species, even though a temporal increase in size was noted. P. silberlingi appears significantly larger than the newly described species Picrodus (= Draconodus) apertus. 相似文献
5.
A new species of aquatic plant, Scutifolium jordanicum gen. et sp. nov., Taylor, Brenner & Basha, is described from the Albian of Jordan. The leaves are microphyllous with a symmetrical, elliptical to suborbiculate shape, convex to rounded apex and base, and actinodromous to palinactinodromous primary venation. The peltate, centrally attached petioles are narrow, elongate, and alternately arranged on similarly sized stems. The leaves appear to be thick and have aerenchyma. Comparisons to plants with centrally peltate leaves and palmate venation and to aquatic plants with floating leaves suggest that S. jordanicum belongs to the Cabombaceae lineage within the Nymphaeales. Cladistic analysis including the fossil and living members of the Nymphaeales shows that the S. jordanicum is basal to the living members of the family and has unique characters not found in any living genera. This is the oldest evidence of the Cabombaceae from the Old World. Inclusion of two other Early Cretaceous peltate leaf fossils in the phylogenetic analysis indicates their affinities to Cabombaceae and that some of the shared derived characters for the living members are progressively acquired in the fossils. These data show the Cabombaceae were widespread in Gondwana and Laurasia by the mid-Cretaceous. 相似文献
6.
《Journal of human evolution》1987,16(1):1-22
The morphological evidence for the phylogenetic relationships of euprimates, archaic primates, and related eutherian orders is reviewed following the methods of Hennigian phylogenetic systematics. Euprimates, the group including living primates and their closest common ancestor, is diagnosed by a suite of shared derived characters of the cranium and posteranium exhibiting relatively unique distributions among Eutheria. Plesiadapiformes, the group of archaic primates generally held to be the sister group to Euprimates, is not demonstrably monophyletic (with or without Microsyopidae). The Superorder Archonta (primates, tree shrews, bats, and colugos) is the only higher-level grouping including Euprimates that is based on uniquely derived morphological characters. Hypotheses of relationships within Archonta ally Euprimates with either tree shrews or some plesiadapiforms (paromomyids and plesiadapids), but the eurprimate-tree shrew clade receives more support from the distribution of derived characters among the taxa studied. Because the higher-level affinities of Euprimates are not well resolved, we advocate equating the Order Primates with the taxon Euprimates. 相似文献
7.
In this paper we report the first occurrence of an endemic African plesiadapiform primate from the early-middle Eocene locality of Glib Zegdou (Hammada du Dra, Algeria). Dralestes (new genus) is a very specialized taxon, and its closest known relative is the enigmatic and controversial genus Azibius from Gour Lazib (Hammada du Dra). We group both together as the Azibiidae (new rank). Dralestes provides the first evidence of the upper dentition in this group. Some critical dental characters, such as a postprotocingulum on upper teeth, consistently reveal a primate status for the azibiids. Dralestes exhibits, however, a very unusual configuration of the upper molars by the enlarged parastyle, the lack of a metaconule, and the ectoloph structure (preparacrista, centrocrista and postmetacrista are aligned in a high blade-like structure). The apparent dental specializations of both lower premolars and molars of azibiids (exaenodonty, large P(4) bearing sharp apical cusps, and M(1) having a highly elongated trigonid) point to potential relationships with Chronolestes and carpolestid plesiadapiforms. A phylogenetic analysis, performed on 55 dental characters scored for 19 primate genera, clarifies the euprimate status of Altiatlasius, and thus indicates that azibiids are the only known plesiadapiforms from Africa. Azibiids are the sister group of the clade carpolestids/Chronolestes in the superfamily Plesiadapoidea. However, the azibiids differ fundamentally from carpolestids by the combined lack of a centroconule and multiple buccal cusps on P(4). The exact position of both Chronolestes and azibiids in the plesiadapoids appears difficult to resolve. A basal position of Chronolestes in this superfamily cannot be ruled out because it exhibits a simple morphology of I(1) and no conule on P(3). Considering this ad hoc hypothesis, azibiids are found to lie outside a clade including carpolestids/plesiadapids/saxonellids, and they are the sister group to Chronolestes. The clade including the carpolestid, saxonellid, and plesiadapid families is characterized by the occurrence of a centroconule on P(3-4). The lack of this trait in Dralestes and Chronolestes could mean that azibiids are basal plesiadapoids that diverged before the evolution of the common ancestor of the three derived plesiadapoid families, i.e. at least around the Paleocene-Eocene boundary or more probably during the Paleocene. The report of the first offshoot in Africa of plesiadapoids enhances the role of Africa in the early primate radiation. 相似文献
8.
Three genera of unstalked crinoids, Zenometra , Sarametra and Psathyrometra , formerly included in the subfamily Zenometrinae of the family Antedonidae, are removed and placed in a distinct family, the Zenometridae. Diagnostic features include a cavernous centrodorsal cavity, a complete basal circlet with a large central lumen and cirrus sockets with a concave fulcral bowl around the lumen. Sarametra nicobarica is synonymized under S. triserialis , which is redescribed in detail. Psathyrometra is redefined and includes only the species P. fragilis , P. congesta and P. bigradata , which are redescribed. P. erythrizon is synonymized under P. fragilis . The four other species formerly included in Psathyrometra are removed to Athrypsometra gen. n., retained in the Antedonidae. The other genera formerly included in the Zenometrinae are considered incertae sedis in the family Antedonidae pending detailed re-examination. Cladistic analysis using the antedonids, Poliometra prolixa (a former zenometrine) and Florometra serratissima , and the thalassometrid, Oceanometra annandalei , as outgroups produces the following tree: ( O. annandalei (( F. serratissima / P. prolixa )((( P. fragilis / P. congesta ) P. bigradata ) ( S. triserialis / Z. columnaris )))). 相似文献
9.
Sergi López-Torres Keegan R. Selig Kristen A. Prufrock Derrick Lin Mary T. Silcox 《Historical Biology》2018,30(1-2):76-88
AbstractPlesiadapiforms, appearing near the Cretaceous-Paleogene boundary, represent the first primate radiation and show a diverse array of tooth morphologies. Dental topographic metrics provide quantitative data on occlusal surface shape. We used three metrics, Dirichlet Normal Energy, Relief Index, and 3D Orientation Patch Count Rotated, to assess changes in the morphology of lower fourth premolars and lower second molars in a taxonomically broad sample of one family of plesiadapiforms, Paromomyidae, stretching more than 15 million years. Our results indicate that paromomyids occupied a more diverse range of dietary categories than suspected. Whereas all paromomyids were likely omnivores, some species show higher levels of insectivory, while other taxa are inferred to have been mixed-feeding omnivores with high levels of fruit intake. The results also show that the more primitive members of the different paromomyid lineages were more insectivorous than the derived and more recent members of those lineages. Relief Index values also show taxonomic signals that are consistent with ancestor-descendant relationships hypothesised for species of Phenacolemur. These results suggest that dental topographic metrics are informative to the study of paromomyids for both dietary categorisation and for the distinction of species at a fine taxonomic level. 相似文献
10.
Keith R. Willmott 《Systematic Entomology》2003,28(3):279-322
Abstract. A two-stage cladistic analysis of 114 characters from adult and immature stage morphology provided phylogenetic hypotheses for the diverse Neotropical nymphalid butterfly genus Adelpha Hübner. Higher-level cladistic relationships were inferred for thirty Adelpha species and twenty other species of Limenitidini, confirming the monophyly of Adelpha as currently conceived and indicating several montane Asian species as potential sister taxa for the genus. Cladistic relationships between all eighty-five Adelpha species were then inferred using three outgroup combinations. Basal and terminal nodes were reasonably resolved and supported, but a low proportion of non-wing pattern characters resulted in weak resolution and support in the middle of the tree. The most basal members of Adelpha feed on the temperate or montane plant family Caprifoliaceae, suggesting that a switch from this family early in the evolutionary history was important in subsequent diversification into tropical lowland habitats. The cladograms confirm suspicions of earlier authors that dorsal mimetic wing patterns have convergently evolved a number of times in Adelpha . The subtribal classification of Limenitidini is discussed and both Lebadea (from Parthenina) and Neptina are transferred to Limenitidina, whereas Cymothoe , Bhagadatta and Pseudoneptis (all formerly Limenitidina) are regarded as incertae sedis . 相似文献
11.
A phylogenetic investigation of a monophyletic lineage of spurge plants, tribe Euphorbieae, was conducted to elucidate evolutionary relationships, to clarify biogeographic patterns, and to reexamine the previous classification of Euphorbieae. Cladistic analyses of the 52 morphological characters of 61 species resulted in 2922 equally most parsimonious trees of 193 steps with a consistency index of 0.34. The strict consensus tree indicates genus Anthostema of subtribe Anthosteminae as a likely sister group to all other members of tribe Euphorbieae. The morphological data support a monophyletic origin of subtribe Euphorbiinae, but the subtribes Anthosteminae and Neoquillauminiinae did not form monophyletic groups. Although the previous taxonomic treatments within tribe Euphorbieae have supported the generic status of Pedilanthus, Monadenium, Synadenium, Chamaesyce, and Elaeophorbia, the results of this analysis do not support generic placement of them based on cladistic principles. Recognition of these groups as genera results in Euphorbia becoming a paraphyletic group. One solution to this problem in Euphorbieae is to divide the largest genus Euphorbia into several monophyletic genera and to keep the generic ranks for previously recognized genera. The distribution of basal endemic genera in Euphorbieae showed African and east Gondwanan affinities and strongly indicated that the ancestor of Euphorbieae originated prior to the breakup of Gondwanaland from an old group in Euphorbiaceae. However, some recent African taxa of Euphorbia should be interpreted by transoceanic dispersal from the New World ancestors. 相似文献
12.
Abstract: A new genus and species of basal non‐Viverravidae Carnivoramorpha, Dawsonicyon isami, is named and described. This new taxon is based upon DMNH 19585, an almost complete skeleton, which was collected from the Black’s Fork Member (informal ‘Bridger B’ subunit) of the Bridger Formation in southwestern Wyoming, USA. The specimen is incorporated into an existing craniodental data matrix, and the associated phylogenetic analyses support the identification of this species as a new basal carnivoramorphan. This new taxon is dentally compared to all known genera of non‐viverravid basal carnivoramorphans, as well as with all known species of the problematic genus Miacis. Postcrania are compared in detail with other described specimens of non‐viverravid basal carnivoramorphans and more generally with known postcrania of viverravids. Preliminary functional interpretations of a scansorial locomotor mode are offered for this new taxon. Its implications for the diversity of middle Eocene basal carnivoramorphans is briefly discussed, including expansion of the already high diversity in the Black’s Fork Member of the Bridger Formation (at least 11 species in 8 genera). 相似文献
13.
Sinha, A., Datta, A., Madhusudan, M. D., & Mishra, C. (2005. Macaca munzala: A new species from western Arunachal Pradesh, northeastern India. International Journal of Primatology, 26, 977–989) discovered Arunachal macaques (Macaca munzala), a species new to science, in the eastern Himalaya of Arunachal Pradesh in northeastern India. They depicted the holotype
and paratypes of the species in photographs, and a specimen of the species had been unavailable for preservation and examination.
In March 2005, we obtained an entire specimen of an adult male Macaca munzala, which we propose as a voucher specimen for the species. We provide detailed morphological and anatomical measurements of
the specimen and examine its affinities with other macaques. Macaca munzala appears to be unique among macaques in craniodental size and structure, baculum, and aspects of caudal structure, while exhibiting
affinities with the other members of the sinica-group to which it belongs. We summarize our insights on the origins and phylogeny of Macaca munzala. Finally, we review the current conservation status of the macaques, which are threatened by extensive hunting in the only
2 districts of Arunachal Pradesh where they are documented to occur. 相似文献
14.
Arboreal primates have distinctive intrinsic hand proportions compared with many other mammals. Within Euarchonta, platyrrhines and strepsirrhines have longer manual proximal phalanges relative to metacarpal length than colugos and terrestrial tree shrews. This trait is part of a complex of features allowing primates to grasp small-diameter arboreal substrates. In addition to many living and Eocene primates, relative elongation of proximal manual phalanges is also present in most plesiadapiforms. In order to evaluate the functional and evolutionary implications of manual similarities between crown primates and plesiadapiforms, we measured the lengths of the metacarpal, proximal phalanx, and intermediate phalanx of manual ray III for 132 extant mammal species (n=702 individuals). These data were compared with measurements of hands in six plesiadapiform species using ternary diagrams and phalangeal indices. Our analyses reveal that many arboreal mammals (including some tree shrews, rodents, marsupials, and carnivorans) have manual ray III proportions similar to those of various arboreal primates. By contrast, terrestrial tree shrews have hand proportions most similar to those of other terrestrial mammals, and colugos are highly derived in having relatively long intermediate phalanges. Phalangeal indices of arboreal species are significantly greater than those of the terrestrial species in our sample, reflecting the utility of having relatively long digits in an arboreal context. Although mammals known to be capable of prehensile grips demonstrate long digits relative to palm length, this feature is not uniquely associated with manual prehension and should be interpreted with caution in fossil taxa. Among plesiadapiforms, Carpolestes, Nannodectes, Ignacius, and Dryomomys have manual ray III proportions that are unlike those of most terrestrial species and most similar to those of various arboreal species of primates, tree shrews, and rodents. Within Euarchonta, Ignacius and Carpolestes have intrinsic hand proportions most comparable to those of living arboreal primates, while Nannodectes is very similar to the arboreal tree shrew Tupaia minor. These results provide additional evidence that plesiadapiforms were arboreal and support the hypothesis that Euarchonta originated in an arboreal milieu. 相似文献
15.
Comparative sequence data for the chloroplast encodedrbc L genehas been obtained for species representing the basal lineagesin the proposed phylogeny of Powellet al. (Annals of Botany77:305315, 1996), with the aim of testing the delimitationof the family and the validity of the supra-generic taxa proposed,and estimating relationships within the family. Cladistic analysesindicate that EpacridaceaesensuPowellet al. (1996) is not monophyletic.Lebetanthus,a monotypic genus from South America commonly placed withinthe family, mostly near the Tasmanian endemicPrionotes, is shownto be closer toGaultheriaand other members of the ericaceoustribe Andromedeae. The hypothetical phylogeny of Powellet al.(1996) is evaluated in the light of this preliminary analysisof relationships within the family. The data do not supportthe recognition of the two subfamilies, Richeoideae and Epacridoideae,of Watson Epacridaceae; Ericales; molecular systematics; molecular systematics; rbc L 相似文献
16.
Fossilized pistillate inflorescences, fruits, and pollen grains from the Turonian (~90 million years before present) of New Jersey are described as a new genus, Microaltingia, in the family Hamamelidaceae. The fossils are remarkably preserved in exceptional detail. Several morphological and anatomical characters suggest affinities with Hamamelidaceae. These include capitate inflorescences, florets with a hypanthium, two-carpellate gynoecia, perigynous flowers, tricolpate reticulate pollen, a three-layered carpel wall, scalariform perforation plates with oblique end walls, and scalariform and opposite/alternate intervascular pitting. The gross morphology of pistillate inflorescences, unisexual flowers, phyllome structure, numerous ovules per carpel, and mode of carpel dehiscence indicate affinities with subfamily Altingioideae, which includes the modern genera Liquidambar and Altingia. Cladistic analysis using a previously published morphological matrix and scoring the fossil for available characters supports the position of the fossil as a sister taxon of modern Altingioideae. Although the fossil exhibits a mosaic of characters found within modern Hamamelidaceae, it is not identical to any modern taxon. Based on cladistic analysis, the fossil appears to be a basal "altingioid" that lacks the derived pollen found in extant Altingioideae and retains the more plesiomorphic tricolpate pollen found in the rest of Hamamelidaceae. The floral characters of the fossils, including phyllomes with stomata, short and straight styles, and small perprolate pollen grains, also indicate the possibility of insect pollination. 相似文献
17.
18.
Recent discoveries of new fossil hominid species have been accompanied by several phylogenetic hypotheses. All of these hypotheses are based on a consideration of hominid craniodental morphology. However, Collard and Wood (2000) suggested that cladograms derived from craniodental data are inconsistent with the prevailing hypothesis of ape phylogeny based on molecular data. The implication of their study is that craniodental characters are unreliable indicators of phylogeny in hominoids and fossil hominids but, notably, their analysis did not include extinct species. We report here on a cladistic analysis designed to test whether the inclusion of fossil taxa affects the ability of morphological characters to recover the molecular ape phylogeny. In the process of doing so, the study tests both Collard and Wood's (2000) hypothesis of character reliability, and the several recently proposed hypotheses of early hominid phylogeny. One hundred and ninety-eight craniodental characters were examined, including 109 traits that traditionally have been of interest in prior studies of hominoid and early hominid phylogeny, and 89 craniometric traits that represent size-corrected linear dimensions measured between standard cranial landmarks. The characters were partitioned into two data sets. One set contained all of the characters, and the other omitted the craniometric characters. Six parsimony analyses were performed; each data set was analyzed three times, once using an ingroup that consisted only of extant hominoids, a second time using an ingroup of extant hominoids and extinct early hominids, and a third time excluding Kenyanthropus platyops. Results suggest that the inclusion of fossil taxa can play a significant role in phylogenetic analysis. Analyses that examined only extant taxa produced most parsimonious cladograms that were inconsistent with the ape molecular tree. In contrast, analyses that included fossil hominids were consistent with that tree. This consistency refutes the basis for the hypothesis that craniodental characters are unreliable for reconstructing phylogenetic relationships. Regarding early hominids, the relationships of Sahelanthropus tchadensis and Ardipithecus ramidus were relatively unstable. However, there is tentative support for the hypotheses that S. tchadensis is the sister taxon of all other hominids. There is support for the hypothesis that A. anamensis is the sister taxon of all hominids except S. tchadensis and Ar. ramidus. There is no compelling support for the hypothesis that Kenyanthropus platyops shares especially close affinities with Homo rudolfensis. Rather, K. platyops is nested within the Homo + Paranthropus + Australopithecus africanus clade. If K. platyops is a valid species, these relationships suggest that Homo and Paranthropus are likely to have diverged from other hominids much earlier than previously supposed. There is no support for the hypothesis that A. garhi is either the sister taxon or direct ancestor of the genus Homo. Phylogenetic relationships indicate that Australopithecus is paraphyletic. Thus, A. anamensis and A. garhi should be allocated to new genera. 相似文献
19.
The Vernonieae is one of the major tribes of the largest family of flowering plants, the sunflower family (Compositae or Asteraceae), with ca. 25,000 species. While the family's basal members (the Barnadesioideae) are found in South America, the tribe Vernonieae originated in the area of southern Africa/Madagascar. Its sister tribe, the Liabeae, is New World, however. This is the only such New/Old World sister tribe pairing anywhere in the family. The Vernonieae is now found on islands and continents worldwide and includes more than 1500 taxa. The Vernonieae has been called the "evil tribe" because overlapping character states make taxonomic delimitations difficult at all levels from the species to the subtribe for the majority of taxa. Juxtaposed with these difficult-to-separate entities are monotypic genera with highly distinctive morphologies and no obvious affinities to any other members of the tribe. The taxonomic frustration generated by these contrary circumstances has resulted in a lack of any phylogeny for the tribe until now. A combined approach using DNA sequence data from two chloroplast regions, the ndhF gene and the noncoding spacer trnL-F, and from the nuclear rDNA ITS region for 90 taxa from throughout the world was used to reconstruct the evolutionary history of the tribe. The data were analyzed separately and in combination using maximum parsimony (MP), minimum evolution neighbor-joining (NJ), and Bayesian analysis, the latter producing the best resolved and most strongly supported tree. In general, the phylogeny shows Old World taxa to be basal and New World taxa to be derived, but this is not always the case. Old and New World species are found together in two separate and only distantly related clades. This is best explained by long-distance dispersal with a minimum of two trans-oceanic exchanges. Meso/Central America has had an important role in ancient dispersals between the Old and New World and more recent movements from South to North America in the New World. 相似文献
20.
The phylogenetic relationships and systematic position of the digenean genus Omphalometra Looss, 1899 and several other closely related genera, have always been controversial and opinions of different authors on the systematic rank and content of this group have varied greatly. Molecular analysis based on the partial sequences of the large subunit ribosomal DNA gene of representatives of the genera Omphalometra, Rubenstrema and Neoglyphe as well as previously published sequences of members of five families of Plagiorchioidea, has demonstrated: (1) close phylogenetic relationships between these three genera, and (2) a strong support of their position within the family Plagiorchiidae as a well-defined separate clade considered here as a subfamily Omphalometrinae. Molecular data do not support the close affinities of the members of Omphalometrinae and genus Opisthioglyphe as has been suggested by majority of previous authors. Among Omphalometrinae, Omphalometra flexuosa (a parasite of moles, Talpidae) occupies a basal position in relation to Rubenstrema exasperatum and Neoglyphe locellus (both parasitic in shrews, members of the more evolutionary advanced family Soricidae). An extremely low level of lsrDNA sequence divergence between Neoglyphe and Rubenstrema suggests very close phylogenetic relationships of these two genera. Results of the molecular analysis are briefly discussed in comparison with the previously published systems. 相似文献