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1.
Notharctine adapiform primates are an abundant element of early (Wasatchian) and middle (Bridgerian) Eocene faunal assemblages from the western interior of North America. Early Eocene notharctine samples are dominated by Cantius with Pelycodus and Copelemur being much rarer and more restricted in their geographic distribution. Cantius is replaced in the middle Eocene by Notharctus and Smilodectes, both of which are common but less widespread, being best known from southwestern Wyoming. The origin of these two middle Eocene taxa has not been well understood, due to a lack of transitional Wasatchian-Bridgerian notharctine faunal samples or because known samples had not been adequately studied. Field work at South Pass in the Greater Green River Basin has produced a relatively large sample of earliest Bridgerian notharctines. Combining this sample with a large, but previously under-studied, sample of notharctines from the latest Wasatchian and earliest Bridgerian in the Wind River Basin has clarified the relationships among Notharctus,Smilodectes, and earlier occurring notharctines. Notharctus first appears in the latest Wasatchian (Wa7), represented by N. venticolus. Phylogenetic analysis supports a Notharctus clade that shares sister taxon status with Cantius nunienus and indicates that Notharctus arose through bifurcation of the lineage containing the last common ancestor of C. nunienus and Notharctus. The origins of Smilodectes are less clear. Phylogenetic analysis supports a clade consisting of Smilodectes and Copelemur, but the origins of both taxa are not established as yet. North American notharctines are typified by relatively low taxonomic diversity, but relatively high abundance and high dental morphological variation (disparity). These attributes are opposite to those of North American omomyids, reflecting differences in ecomorphospace between these two primate radiations.  相似文献   

2.
Previously undescribed notharctine primate fossils are reported from the early Eocene San Jose Formation, San Juan Basin, New Mexico, and the early Eocene Wasatch Formation, southern Wyoming. These collections include the most complete specimens yet discovered of the poorly known species Copelemur tutus and Copelemur praetutus; the first upper dentitions of Cantius angulatus and Cantius frugivorus from the type area of these taxa; and fossils attributable to two new notharctine species, Copelemur australotutus and Smilodectes gingerichi. These new fossils reveal that current ideas concerning notharctine phylogeny are incorrect. Two major, monophyletic clades are apparent within the subfamily: the tribe Copelemurini, consisting of the genera Copelemur and Smilodectes, and the tribe Notharctini, comprising the genera Cantius, Pelycodus, and Notharctus. Analysis of the paleobiogeographic distribution of the Copelemurini indicates that this clade was limited to more southerly regions of western North America during early Eocene time. Northward migration of more tropical habitats during the late Wasatchian and early Bridgerian in western North America, associated with an overall climatic warming trend through the early and middle Eocene, appears to have allowed several mammalian taxa, including Smilodectes, to extend their ranges northward during this time interval. Such taxa thus possess diachronous distributions and have been partly responsible for the long-standing confusion regarding the biostratigraphic correlation of early Eocene faunas from New Mexico with those from Wyoming. Based on several taxa which are also known from the Wasatchian of Wyoming, the age of the San Jose Formation appears to be middle Wasatchian.  相似文献   

3.
Phylogenetic relationships among gekkotan lizards were estimated from five nuclear protein-coding genes in separate and combined analyses using maximum parsimony, maximum likelihood and Bayesian analyses. All analyses recovered a monophyletic trans-Atlantic gecko clade (Phyllodactylidae) consisting of the genera Asaccus, Haemodracon, Homonota, Phyllodactylus, Phyllopezus, Ptyodactylus, Tarentola and Thecadactylus . No other phylogenetic or taxonomic hypotheses have proposed linking these genera, which have been consistently grouped with other taxa outside of the clade. In this paper, we determine the relationships of this new clade to other major gekkotan groups, evaluate previous phylogenetic hypotheses regarding constituent members of this novel clade, and critically examine the use of historically important morphological characters in gekkotan systematics as they relate to this novel clade, specifically — phalangeal formulae, hyoid morphology and external structure of the toe-pads.  相似文献   

4.
We present a mitochondrial gene tree for representative species of all the genera in the subfamily Myobatrachinae, with special emphasis on Crinia and Geocrinia. This group has been the subject of a number of long-standing taxonomic and phylogenetic debates. Our phylogeny is based on data from approximately 780 bp of 12S rRNA and 676 bp of ND2, and resolves a number of these problems. We confirm that the morphologically highly derived monotypic genera Metacrinia, Myobatrachus, and Arenophryne are closely related, and that Pseudophryne forms the sister group to these genera. Uperoleia and the recently described genus Spicospina are also part of this clade. Our data show that Assa and Geocrinia are reciprocally monophyletic and together they form a well-supported clade. Geocrinia is monophyletic and the phylogenetic relationships with the genus are fully resolved with two major species groups identified: G. leai, G. victoriana, and G. laevis; and G. rosea, G. alba, and G. vitellina (we were unable to sample G. lutea). We confirm that Taudactylus forms the sister group to the other myobatrachine genera, but our data are equivocal on the phylogenetic position of Paracrinia. The phylogenetic relationships among Crinia species are well resolved with strong support for a number of distinct monophyletic clades, but more data are required to resolve relationships among these major Crinia clades. Crinia tasmaniensis and Bryobatrachus nimbus form the sister clade to the rest of Crinia. Due to the lack of generic level synapomorphies for a Bryobatrachus that includes C. tasmaniensis, we synonymize Bryobatrachus with Crinia. Crinia georgiana does not form a clade distinct from other Crinia species and so our data do not support recognition of the genus Ranidella for other Crinia species. Crinia subinsignifera, C. pseudinsignifera, and C. insignifera are extremely closely related despite differences in male advertisement call. A preliminary investigation of phylogeographic substructure within C. signifera revealed significant divergence between samples from across the range of this species.  相似文献   

5.
The phylogenetic structure of the tricolpate clade (or eudicots) is presented through a survey of their major subclades, each of which is briefly characterized. The tricolpate clade was first recognized in 1989 and has received extensive phylogenetic study. Its major subclades, recognized at ordinal and familial ranks, are now apparent. Ordinal and many other suprafamilial clades are briefly diagnosed, i.e., the putative phenotypic synapomorphies for each major clade of tricolpates are listed, and the support for the monophyly of each clade is assessed, mainly through citation of the pertinent molecular phylogenetic literature. The classification of the Angiosperm Phylogeny Group (APG II) expresses the current state of our knowledge of phylogenetic relationships among tricolpates, and many of the major tricolpate clades can be diagnosed morphologically.  相似文献   

6.
Sequences of mitochondrial genes 12S and 16S rRNA (2 445 bp) and the region of the nuclear beta-spectrin gene (828 bp) were analyzed in members of the family Cervidae and in other artiodactyls. Several molecular synapomorphies characteristic both of Cervidae and musk deer have been found. According to our data, Cervidae is a sister clade to Bovidae, which are very close to Moschidae. The family Giraffidae is exterior to this common clade, while Antilocapridae occupies a more basal position. The family Cervidae proper splits into three clades including the genera Cervus and Muntiacus (1), Capreolus, Hydropotes, Alces (2), and Rangifer, Odocoileus, and the remaining genera (3). In general, our phylogenetic reconstructions conform to the results of earlier molecular genetic studies, but substantially differ from the traditional taxonomy of Ruminantia.  相似文献   

7.
In order to enhance our understanding of the evolutionary history of squirrel monkeys (Saimiri spp.), we newly sequenced and analyzed data from seven complete mitochondrial genomes representing six squirrel monkey taxa. While previous studies have lent insights into the taxonomy and phylogeny of the genus, phylogenetic relationships and divergence date estimates among major squirrel monkey clades remain unclear. Using maximum likelihood and Bayesian procedures, we inferred a highly resolved phylogenetic tree with strong support for a sister relationship between Saimiri boliviensis and all other Saimiri, for monophyly of Saimiri oerstedii and Saimiri sciureus sciureus, and for Saimiri sciureus macrodon as the sister lineage to the S. oerstedii/S. s. sciureus clade. We inferred that crown lineages for extant squirrel monkeys diverged around 1.5 million years ago (MYA) in the Pleistocene Epoch, with other major clades diverging between 0.9 and 1.1 MYA. Our results suggest a relatively recent timeline of squirrel monkey evolution and challenge previous conceptions about the diversification of the genus and its expansion into Central America.  相似文献   

8.
The euglenoids are an ancient and extremely diverse lineage of eukaryotic flagellates with unclear relationships among taxa. Synapomorphies for the euglenoids include a surface pellicle and a closed mitosis with a series of separate sub-spindles. The taxonomy currently in use is inconsistent with the available data and needs revision. Most euglenoid phylogenies are largely intuitive reconstructions based on a limited number of morphological characters. Therefore, we have added molecular characters from the Small Subunit (SSU) rDNA to generate an overall phylogenetic framework for the euglenoids. SSU rDNA sequences from photosynthetic, osmotrophic, and phagotrophic euglenoids were aligned based on secondary structure. Phylogenetic analysis using the conserved areas of the sequence was performed using parsimony, maximum likelihood, and distance methods. Trees derived using different criteria are in agreement. The euglenoids form a distinct monophyletic clade with phagotrophic members diverging prior to the phototrophic and osmotrophic members. Among photosynthetic members, the biflagellate form diverged prior to the uniflagellate form. Additionally, the genus Euglena appears to be paraphyletic, with osmotrophic taxa, such as Astasia and Khawkinea, diverging independently within the clade containing the photosynthetic genus Euglena.  相似文献   

9.
The tribe Miliuseae (Annonaceae) comprises six genera distributed in Asia: Alphonsea, Mezzettia, Miliusa, Orophea, Platymitra, and Phoenicanthus. A phylogenetic study to investigate the putative monophyly of the tribe and the intergeneric relationships is presented here. Nucleotide sequences of the plastid gene rbcL, trnL intron, and trnL-trnF intergenic spacer were analyzed from 114 Annonaceae taxa, including 24 Miliuseae species and two outgroups using maximum parsimony and Bayesian inference. The two data sets (rbcL and the trnL-trnF regions) were analyzed separately and in combination. Miliuseae were found to be polyphyletic due to the position of Mezzettia and are part of a large, predominantly Asian and Central-American clade (miliusoid clade). Although intergeneric relationships were poorly resolved, all genera, except Polyalthia, were monophyletic, supporting previous generic delimitation based on morphology. A group of three Polyalthia species seems the most likely sister group of Miliusa. Several infrageneric groups of Miliusa, Orophea, and Polyalthia are supported by both molecular and morphological data. No morphological synapomorphies have yet been found for the miliusoid clade. Molecular clades within the miliusoid clade, however, can be characterized by size and the shape of the outer petals, number of ovules per carpel, and the size of the fruits.  相似文献   

10.
The Herpestidae are small terrestrial carnivores comprising 18 African and Asian genera, currently split into two subfamilies, the Herpestinae and the Galidiinae. The aim of this work was to resolve intra-familial relationships and to test the origin of sociality in the group. For this purpose we analysed sequences of the complete cytochrome b gene for 18 species of Herpestidae. The results showed that the mongooses were split into three clades: (1) the Malagasy taxa (Galidiinae and Cryptoprocta), (2) the true social mongooses and (3) the solitary mongooses, each group being also supported by morphological and chromosomal data. Our results suggested unexpected phylogenetic relationships: (1) the genus Cynictis is included in the solitary mongoose clade, (2) the genera Liberiictis and Mungos are sister-group, and (3) the genus Herpestes is polyphyletic. We examined the evolution of the sociality in mongooses by combining behavioural traits with the cytochrome b data. Some of the behavioural traits provided good synapomorphies for characterizing the social species clade, showing the potential benefit of using such characters in phylogeny. The mapping of ecological and behavioural features resulted in hypothesizing solitary behavior and life in forest as the conditions at the base of the mongoose clade.  相似文献   

11.
The family Characidae, including more than 1000 species, lacks a phylogenetic diagnosis, with many of its genera currently considered as incertae sedis . The aims of the present study are to propose a phylogenetic diagnosis and to assess higher-level relationships of and within Characidae. In this regard, 360 morphological characters are studied for 160 species of Characidae and related families. Phylogenetic analyses under implied weighting and self-weighted optimization are presented, exploring a broad range of parameters. The analysis under self-weighted optimization is innovative for this size of matrices. Familial status of Serrasalmidae is supported, and Acestrorhynchidae and Cynodontidae are included in a monophyletic Characidae. Engraulisoma taeniatum is transferred from Characidae to Gasteropelecidae. Thus constituted, the monophyly of Characidae is supported by seven synapomorphies. A new subfamily, Heterocharacinae, is proposed, and the subfamilies Aphyocharacinae, Aphyoditeinae, Characinae, Gymnocharacinae, and Stevardiinae are redefined. The Glandulocaudinae are included in Stevardiinae together with remaining members of "clade A" ( sensu Malabarba and Weitzman, 2003 . Comun. Mus. Ciênc. Tecnol. PUCRS, Sér. Zool. 16, 67–151.) and the genera Aulixidens and Nantis . Most incertae sedis genera are assigned, at least tentatively, to a phylogenetically diagnosed clade.  相似文献   

12.
Spermiogenesis and sperm ultrastructure from 21 species of Moenkhausia and others related genera are described. To evaluate the phylogenetic signals, 18 unordered characters were utilized in implied weighting analysis through the program TNT 1.1. Four variations of spermiogenesis were found. In the earliest spermatids, the nucleus can be positioned lateral, eccentric, strongly eccentric or nearly medial in relation to the distal centriole. The nuclear rotation can be present or absent. These spermiogenesis processes are related or intermediate to Type I and Type III. Taking into account the degrees of nuclear rotation during the spermiogenesis and other characteristics, distinct forms of spermatozoa are observed among the species analyzed. The phylogenetic analysis yielded a single most parsimonious tree with fit value 2.70000 and the topology obtained founds Moenkhausia as non‐monophyletic. However, some hypothesis of relationships previously proposed viz the clade 20, which contains the type species Moenkhausia xinguensis, is recovered herein. This clade is supported by five synapomorphies, and it allows the supposition that these species constitute a monophyletic group. The whole topology is presented and discussed.  相似文献   

13.
The Characinae is a subunit of the Characidae of special significance in including Charax, the type genus of the family and the order Characiformes. Twelve genera and 79 species have been traditionally assigned to the Characinae, but the subfamily still lacks a phylogenetic diagnosis. Herein, a data matrix including 150 morphological characters and 64 taxa (35 species representing all genera of the Characinae and 29 included in other lineages within the Characiformes) was submitted to two cladistic analyses that differ in the inclusion/exclusion of Priocharax due to the difficulty of coding most of the character states in the miniature species of this genus. Both analyses resulted in a non‐monophyletic Characinae and this subfamily is herein restricted to only seven of the original 12 genera forming the clade (Phenacogaster((Charax Roeboides)(Acanthocharax(Cynopotamus(Acestrocephalus Galeocharax))))), which is supported by ten non‐ambiguous synapomorphies and is more closely related to other genera of the Characidae than those traditionally placed in the subfamily. A second clade includes the members of the tribe Heterocharacini (Lonchogenys(Heterocharax Hoplocharax)) as the sister‐group of Gnathocharax, supported by seven non‐ambiguous synapomorphies. This clade is more closely related to a taxon formed by Roestes and Gilbertolus based on seven non‐ambiguous synapomorphies. Results do not corroborate a close relationship between RoestesGilbertolus and the Cynodontinae. Inclusion of the genus Priocharax suggests that it is related more closely to the Heterocharacini, but the profound modifications in its anatomy possibly related to ontogenetic truncations obscure a better understanding of its relationships. A new classification of the Characinae and the Heterocharacinae is proposed. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 809–915.  相似文献   

14.
A new family of damselflies, based on Latibasalia elongata gen. et sp. nov. and L. quispeae gen. et sp. nov., is erected from the Upper Palaeocene Maíz Gordo Formation, north-western Argentina. Latibasaliidae fam. nov. can be included in the Zygoptera: Caloptera: Eucaloptera: Amphipterygida: Amphipterygoidea. Its phylogenetic relationships within the clade Eucaloptera Bechly, 1996 are discussed. Within Amphipterygoidea, Latibasaliidae could be closely related to Pseudolestidae or to the 'thaumatoneurid' genera Petrolestes and Congqingia because they share the absence of secondary antenodal crossveins of first and second rows and the absence of antesubnodal crossveins. These characters could be potential synapomorphies of these taxa but they are somewhat homoplastic within the Zygoptera.  相似文献   

15.
16.
A comprehensive phylogenetic investigation was performed to elucidate the cladistic relationships and possible monophyly of therocephalian therapsids (Amniota: Synapsida). The phylogenetic positions of 30 therapsid taxa were examined under maximum parsimony, including 23 therocephalian genera. The analysis incorporated 110 cranial and postcranial characters in order to assess the interrelationships of basal therocephalians and eutherocephalians and their relationships to Cynodontia, representing the most complete review of therocephalian phylogeny to date. The analysis supports the hypothesis that Therocephalia represents the monophyletic sister taxon to Cynodontia, with as many as 15 morphological synapomorphies, in contrast with other recent analyses of lesser taxon sampling. The results also support the hypothesis that Scylacosauridae is more closely related to Eutherocephalia than to the basal therocephalian family Lycosuchidae, supporting a ‘Scylacosauria’ clade. The taxa suggested here to be neotenic forms (e.g. Ictidosuchoides and Ictidosuchops) are positioned near the base of a monophyletic Baurioidea. Neotenic development of the therocephalian feeding apparatus and evolutionary parallelism with cynodonts are suggested to have been important trends in the early evolution of baurioid therocephalians into the Late Permian and Early Triassic.  相似文献   

17.
Despite increased understanding of higher-level relationships in passerine birds in the last 15 years, the taxonomic boundaries and phylogenetic interrelationships of the major groups of the Tyrannida (including the cotingas, manakins, tityrines, and tyrant flycatchers) remain unclear. Here, we present an analysis of DNA sequence data obtained from two nuclear exons, three introns, and one mitochondrial gene for 26 genera of Tyrannida and 6 tracheophone outgroups. The analysis resulted in well-supported hypotheses about the earliest evolution within Tyrannida. The Cotingidae, Pipridae, Tityrinae (sensu) [Prum, R.O., Rice, N.H., Mobley, J.A., Dimmick, W.W., 2000. A preliminary phylogenetic hypothesis for the cotingas (Cotingidae) based on mitochondrial DNA. Auk 117, 236-241], Tyrannidae, and the tyrannid subfamiles Tyranninae and Pipromorphinae (sensu) [Sibley, C.G., Monroe, B. L. Jr., 1990. Distribution and Taxonomy of Birds of the World. Yale University Press, New Haven, CT] were all found to be reciprocally monophyletic (given the present taxon sampling). The Cotingidae and Pipridae form a clade that is the sister group to a well-supported clade including Oxyruncus, the Tityrinae, Piprites, and the Tyrannidae. Oxyruncus is the sister group to the Tityrinae, and Piprites is placed as the sister group to the Tyrannidae. The tyrannid subfamilies Tyranninae and Pipromorphinae are monophyletic sister taxa, but the relationships of Platyrinchus mystaceus to these two clades remains ambiguous. The presence of medial (=internal) cartilages in the syrinx is a synapomorphy for the Oxyruncus-Tityrinae-Piprites-Tyrannidae clade. Although morphological synapomorphies currently support the monophyly of both the Pipridae and the Cotingidae, convergences and/or reversals in morphological character states are common in Tyrannida. The relationship between Oxyruncus and the Tityrinae is congruent with additional syringeal synapomorphies and allozyme distance data. Accordingly, we propose the recognition the family Tityridae within the Tyrannida to include the genera Schiffornis, Laniisoma, Laniocera, Iodopleura, Xenopsaris, Pachyramphus, Tityra, and Oxyruncus.  相似文献   

18.
Neale Monks 《Palaeontology》2002,45(4):689-707
The Hamitidae are a family of mid–Cretaceous heteromorph ammonites including lineages leading to four other families. Problems are outlined in trying to describe the phylogeny of completely extinct groups such as these heteromorph ammonites using the existing cladistic terminology, which is largely concerned with extant taxa and their ancestors. To solve these problems, two new terms are proposed: †crown groups and †stem groups, which are equivalent to crown and stem groups in terms of the evolutionary history of a clade, but are not defined on the basis of extant taxa. Instead they are defined by the topology of the phylogenetic tree, the †crown group being a clade defined by synapomorphies but which gave rise to no descendants. A †stem group is a branch of a phylogenetic tree which comprises the immediate sister groups of a given †crown group but is not itself a clade. Examples of these terms are described here with reference to the phylogeny of the Hamitidae and their descendants. The Hamitidae are paraphyletic and form †stem groups to a number of †crown groups, namely the Anisoceratidae, Baculitidae, Scaphitidae, and Turrilitidae. The definitions of the genera and subgenera are refined with respect to the type species and the clades within which they occur, and four new genera are described: Eohamites , Helicohamites , Sziveshamites , and Planohamites .  相似文献   

19.
Phylogenetic relationships of Croton section Cleodora (Klotzsch) Baill. were evaluated using the nuclear ribosomal ITS and the chloroplast trnL-F and trnH-psbA regions. Our results show a strongly supported clade containing most previously recognized section Cleodora species, plus some other species morphologically similar to them. Two morphological synapomorphies that support section Cleodora as a clade include pistillate flowers in which the sepals overlap to some degree, and styles that are connate at the base to varying degrees. The evolution of vegetative and floral characters that have previously been relied on for taxonomic decisions within this group are evaluated in light of the phylogenetic hypotheses. Within section Cleodora there are two well-supported clades, which are proposed here as subsections (subsection Sphaerogyni and subsection Spruceani). The resulting phylogenetic hypothesis identifies the closest relatives of the medicinally important and essential oil-rich Croton cajucara Benth. as candidates for future screening in phytochemical and pharmacological studies.  相似文献   

20.
白鱼属鱼类的系统发育(鲤形目:鲤科)   总被引:3,自引:3,他引:0  
白鱼属(Anabarilius Cockerell)是我国特有的鲤科鱼类,主要分布于云南东部、中部和四川南部。分布范围不大,但种的分化强烈。 Regan(1904,1908, 1918)最先报道四种白鱼,但均置于Barilius属。尔后,Cockerell(1923)以Barilius andersoni Regan为模式种建立白鱼属;Nichols(1927)、张孝威(1944)、易伯鲁、吴清江(1964)、刘振华、何纪昌(1983)先后记述了部分种和亚种。陈银瑞、褚新洛(1980)在系统整理的基础上,澄清了白鱼属属级分类上的混乱,记述了三新种和一新亚种。何纪昌、王重光(1984)用数值分类法探讨了白鱼属的分类,报道了二新种和一新亚种。至此,白鱼属共包括15个种和亚种。  相似文献   

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