共查询到20条相似文献,搜索用时 15 毫秒
1.
Hans C. Bjerring 《Acta zoologica》1986,67(1):1-4
Since the turn of this century it has been suggested between whiles that brachiopterygians (i.e. the species of Polypterus and Calamoichthys) are actinopterygians. One of the arguments used recently by advocates of this widespread contention is the dermohyal, an exoskeletal branchial-arch element which they assert occurs in both groups. However, this argument has to be rejected: the dermohyal does not exist in brachiopterygian fishes. The writer proposes to maintain the view that brachiopterygians are not actinopterygians until better arguments to the contrary are forthcoming. 相似文献
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3.
Using micropylar ultrastructure for species identification and phylogenetic inference among four species of Sparidae 总被引:1,自引:0,他引:1
Among Sparus sarba, Acanthopagrus latus, A. schlegeli and Pagrus major, P. major had the largest egg size, with the biggest micropyle funnel and the most numerous accessory openings. The reinforcement in the micropyle canals was species specific with eight spiral clockwise, five two-spiral clockwise, seven two-spiral clockwise, and 10 triangular ridges in S. sarba, A. latus, A. schlegeli , and P. major , respectively. A key to identify these four species based on micropyle characters is proposed for future applications. Cladistic analysis by using different parsimonious methods on the morphological character of the micropyle suggested that the generic interrelationship between Sparus and Acanthopagrus was closer than to the genus Pagrus . Furthermore, the congeneric species of A. latus and A. schlegeli were the most closely related, with S. sarba the second, and P. major the last. This result agreed with conclusions obtained from other character suites including morphological, biochemical and molecular data. 相似文献
4.
A novel hypothesis uniting Acipenser stellatus and Pseudoscaphirhynchus as sister groups has recently been proposed based on analysis of DNA sequences. In this paper I compare specimens of A. stellatus and P. kaufmanni, and show that they share several putatively derived similarities in the structure of their skulls, including: the presence of large spines on the dermal bones of skull; lateral extrascapular bones that enclose the confluence of the posttemporal, supratemporal, and otic sensory canals; elongate dorsal rostral bones; border rostral bones distinct in shape from dorsal rostral bones; greatly enlarged jugal that lacks a median flange; rostral canal bones that loop posteriorly at the anterior commissure of the rostral sensory canals; and the presence of an elongate, flat, and broad posterior ventral rostral bone. These similarities support a close relationship between A. stellatus and Pseudoscaphirhynchus, but still remain to be critically tested. 相似文献
5.
BRIAN G. GARDINER FLS BOBB SCHAEFFER JUDY A. MASSERIE 《Zoological Journal of the Linnean Society》2005,144(4):511-525
A review of lower actinopterygian phylogeny has led us to the conclusion that the Cladistia are the sister group of Recent actinopterygians (Actinopteri) and that the extinct Palaeonisciformes are a paraphyletic group, comprising stem-group actinopterygians (e.g. Cheirolepis ), stem-group actinopterans (e.g. Moythomasia ) and relatives of higher actinopterans such as Pteronisculus . Our analysis further concluded that the Acipenseriformes formed a clade together with Saurichthys and Birgeria , which was most parsimoniously resolved when the Acipenseriformes and Saurichthys were sister groups. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 511−525. 相似文献
6.
MIGUEL TREFAUT RODRIGUES ELIZA MARIA XAVIER FREIRE KATIA CRISTINA MACHADO PELLEGRINO JACK W. SITES JR 《Zoological Journal of the Linnean Society》2005,144(4):543-557
A new genus and species of a short limbed and slightly elongate gymnophthalmid lizard is described from the Atlantic rain forests of north-eastern Brazil. The new genus is also characterized by short and stout pentadactyl limbs, presence of prefrontals, absence of frontoparietals, distinctive ear opening and eyelid, two pairs of genials, a distinct collar, smooth, quadrangular, dorsal scales, quadrangular ventrals, fused postfrontal and postorbital bones, and two pairs of sternal ribs. The geographical distribution of the new taxon extends from the state of Rio Grande do Norte to the northern bank of the Rio São Francisco in the state of Alagoas. All specimens were obtained in leaf litter, an observation which agrees with the fossorial habits suggested by the body shape and massive aspect of the head of this species. A phylogenetic analysis based on external morphology, osteology, and molecular data recovered the new lizard as the sister genus to Anotosaura , and Colobosauroides as the sister group to these two. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 543−557. 相似文献
7.
A New Species Of The Late Triassic Rhynchosaur Hyperodapedon From The Santa Maria Formation Of South Brazil 总被引:1,自引:1,他引:0
A new rhynchosaur, Hyperodapedon huenei sp. nov., is described from the Upper Triassic Santa Maria Formation of the Paraná Basin, Brazil. The holotype is an almost complete skull and mandible, collected at Inhamandá, in the state of Rio Grande do Sul, Brazil. The diagnosis of the genus Hyperodapedon Huxley is revised to include not only H. huxleyi Lydekker and H. gordoni Huxley (as generally accepted), but also the new species described here, various specimens usually assigned to ' Scaphonyx fischeri ' Woodward, and ' S '. sanjuanensis Sill. H. huenei sp. nov. exhibits a number of plesiomorphic features and appears to be the least derived species of Hyperodapedon , forming a sister taxon to the remaining members of the genus. A preliminary phylogenetic analysis for the more derived rhynchosaurs is presented. ' Scaphonyx ' sulcognathus Azevedo and Schultz represents the sister taxon of Hyperodapedon , while ' Rhynchosaurus ' spenceri Benton is considered to be a more derived Middle Triassic rhynchosaur. key words : Rhynchosauria, Hyperodapedon , Triassic, Brazil. 相似文献
8.
A new genus Annectobracon (type species A. eventus sp.n. from China, Thailand, Laos and Vietnam) and A. excavata sp.n. from India and Sri Lanka belonging to the tribe Bathyaulacini are described and illustrated, and an identification key to the species is provided. A phylogenetic analysis of the tribes Bathyaulacini and Glyptomorphini is presented, and the new genus is shown to be the sister group of Ischnobracon Baltazar. 相似文献
9.
记述了辽宁西部九佛堂组和义县组中华弓鳍鱼一新种:辽宁中华弓鳍鱼Sinamia liaoningensis,并与该属的其他种进行了比较.新材料具有中华弓鳍鱼科的3个定义特征:单一的顶骨,三对额外肩胛骨和膜质翼耳骨短并与顶骨等长,无疑应归入该科.新种的后眶下骨较小,背鳍长大,鳞片菱形,因此,归入中华弓鳍鱼属.辽宁中华弓鳍鱼在以下几个方面不同于中华弓鳍鱼的5个已知种:体型短粗,吻骨较短,鼻骨近四方形,围眶骨较多(6),前鳃盖骨强烈弯曲,背鳍条较少(18),尾鳍条较多(16),臀鳍鳍基起点到鱼体背缘的鳞列较多(32),鳞片后缘不具锯齿,尾鳍具有纤维状的角质鳍条. 相似文献
10.
逗亚科似逗属鱼类的物种界定保持争议, 系统发育关系尚待解决。研究取样似逗属鱼类所有种, 使用核基因多位点序列重建似逗属鱼类的系统发育关系, 运用分子的物种界定方法并结合形态特征分析厘定我国似逗属鱼类的分类。贝叶斯系统发育树结果表明: 桂林似逗与平江似逗是单系种; 似逗与扁嘴似逗是多系种, 前者包括五个谱系A至E, 后者包括两个谱系A与B。POFAD距离分析和Structurama分析的结果表明似逗和扁嘴似逗的每个谱系是独立遗传种群, BP & P分析结果强烈支持它们是不同种。*Beast物种树结果揭示: 扁嘴似逗谱系B位于似逗属鱼类的基部位置; 似逗谱系A与B是姊妹群关系, 似逗谱系C是扁嘴似逗谱系A的姊妹群, 它们一起与桂林似逗形成姊妹群关系; 似逗谱系D与E是姊妹群关系, 它们一起是平江似逗的姊妹群。结合形态证据, 对我国似逗属鱼类分类厘定如下: 限定严格意义似逗包括似逗谱系A+B; 恢复长吻似逗(Pseudogobio longirostris Mori, 1934)给予似逗谱系C分类名; 似逗谱系D与E是隐存种, 桂林似逗与平江似逗是有效种。 相似文献
11.
Bravo GA Remsen JV Whitney BM Brumfield RT 《Molecular phylogenetics and evolution》2012,65(1):287-293
The Thamnophilidae is a diverse radiation of insectivorous passerine birds that comprises nearly 220 species and is mostly restricted to the lowlands and lower montane forests of the Neotropics. Current classification within Thamnophilidae relies primarily on morphological variation, but recent incorporation of molecular and vocal data has promoted changes at various taxonomic levels. Here we demonstrate that the genus Terenura is polyphyletic because Terenura callinota, T. humeralis, T. spodioptila, and T. sharpei are phylogenetically distant from the type species of the genus, Terenura maculata. More importantly, the former four species are not particularly closely related to any other thamnophilids and represent a clade that is sister to all other members of the family. Because no genus name is available for this previously undetected lineage in the Thamnophilidae, we describe the genus Euchrepomis for callinota, humeralis, spodioptila, and sharpei, and erect the subfamily Euchrepomidinae. We discuss the taxonomic and evolutionary significance of this divergent lineage. This study highlights the importance of taxonomic coverage and the inclusion of type taxa to redefine classifications to reflect accurately evolutionary relationships. 相似文献
12.
A second species of the enigmatic lampyrid genus Oculogryphus is described and figured as Oculogryphus bicolorsp. n. from Vietnam. The definition of the genus is slightly modified with consideration of newly detected morphological variation from this species. According to a comprehensive phylogenetic analysis including nearly 80% of documented lampyrid genera, Oculogryphus is the putative sister group to Stenocladius s. str. within the paraphyletic group of Ototretinae-Ototretadrilinae.The classification of Stenocladius is briefly discussed in this context. 相似文献
13.
Schizodelphis sulcatus is the type species of the Eurhinodelphinid genus Schizodelphis and was until now only known from a rather fragmentary specimen, lacking some important parts of the skull (vertex, ear bones and apex of rostrum). The study of a well-preserved skull of S. sulcatus Gervais, discovered in the lower Miocene of Hérault (France), helps to improve the diagnosis of this enigmatic species. Diagnostic features include the low height at the base of the rostrum, the lower position of the paroccipital process compared to the height of the postglenoid process in lateral view, the ventrally deflected postglenoid process and the ovoid-shaped nasals. It also confirms that the type species of Schizodelphis is indeed distinct. For the first time in Schizodelphis, the vertex is preserved and the ear bones are found in anatomic connection with the basicranium. A cladistic analysis of cranial characters of Eurhinodelphinidae, including ear bones, is performed and reveals a close phylogenetic relationship between S. sulcatus and the North American species Schizodelphis barnesi. This analysis also highlights some apomorphies of the genus as the smoothly laterally deflected anterior spine of the bulla in ventral view and the reestablishment of the contact between the falciform process of the squamosal and the lateral lamina of the pterygoid. Conversely, the attribution of Schizodelphis morckhoviensis to the genus Schizodelphis is questioned by this analysis. 相似文献
14.
Kelly CM Barker NP Villet MH Broadley DG Branch WR 《Molecular phylogenetics and evolution》2008,47(3):1045-1060
This study constitutes the first evolutionary investigation of the snake family Psammophiidae--the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's family-level snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris. 相似文献
15.
Data are presented on allozyme variation between 15 populations of the stenophagous capitulum weevil, Larinus cynarae , and three populations of its congener, L. latus , that had been collected throughout the northern mediterranean range of these species. A phenetic analysis of these data revealed no direct relationship between genetic variation and host-plant association within L. cynarae , but there was a strong geographical structuring of allozyme patterns. Most of the genetic variation was due to differences between geographical regions and variation within these was small. Wright's F ST values showed that Italian and Greek populations of L. cynarae were most distinct from L. latus , with southern Iberian, northern Spanish and French populations increasingly less so. This pattern was associated with a cline in the frequencies of certain alleles along this geographical arc from France to Greece. A phenogram of Nei's genetic distances indicated the close genetic relationship between the two species of Larinus and separated the populations of L. cynarae into three allopatric groups. These groups have different host-plant spectra - dominated by Cynara cardunculus in Italy and Greece, Cynara humilis/Onopordum in southern Iberia and Onopordum spp. in France/Northern Spain - and can be considered to be host biotypes of L. cynarae. L. latus , which occurs in Greece and further east is also an Onopordum specialist. An analysis of the phylogeny of this group of Larinus indicates a primary separation into eastern ( L. latus ) and western ( L. cynarae ) taxa, with further branching of the L. cynarae lineage into the putative host-biotypes. An hypothesis for the evolution of these taxa is given, based on the evolutionary history of host-plant taxa and geographical constraints. 相似文献
16.
Fabian Pérez-Miranda Omar Mejía Alfonso A. González-Díaz Norberto Martínez-Méndez Eduardo Soto-Galera Gerardo Zúñiga Oldrich Říčan 《Journal of fish biology》2020,96(6):1370-1378
In the present study we evaluated the putative cases of sympatric speciation in the genus Herichthys by studying the variation in head shape using principal component analysis, phylomorphospace and reconstructions of the ancestral states of feeding preferences. Herichthys includes both allopatric and sympatric sister species, as well as sympatric unrelated species and thus offers great potential for evolutionary studies of putatively sympatric speciation. Herichthys is the northernmost group of cichlids in America and one of the most ecologically disparate genera within Middle American cichlids. Fifteen anatomical points were recorded on the heads of 293 specimens of the 11 species recognized within the genus. The results show that in spite of having wide variation in consumed diets, most species of Herichthys are close in morphospace. However, morphological variation was great among the two pairs of sympatric sister species in agreement with the suggested sympatric model of speciation. 相似文献
17.
Phylogenetic relationships within Plantago (Plantaginaceae): evidence from nuclear ribosomal ITS and plastid trnL-F sequence data 总被引:1,自引:0,他引:1
NINA RØNSTED MARK W. CHASE DIRK C. ALBACH MARIA ANGELICA BELLO 《Botanical journal of the Linnean Society. Linnean Society of London》2002,139(4):323-338
A molecular phylogenetic study of Plantago L. (Plantaginaceae) analysed nucleotide variation in the internal transcribed spacers (ITS) of nuclear ribosomal and plastid trnL-F regions. Included are 57 Plantago species, with two Aragoa species as the ingroup and three Veronica species as the outgroup. Phylogenetic analysis using maximum parsimony identified five major clades, corresponding to the taxonomic groups Plantago subgenera Plantago, Coronopus, Psyllium, Littorella and Bougueria . Aragoa is sister to genus Plantago . Plantago subgenus Littorella is sister to the other subgenera of Plantago . The results are in general correlated with a morphological phylogenetic study and iridoid glucoside patterns, but Plantago subgenus Albicans is paraphyletic and should be included in Plantago subgenus Psyllium sensu lato to obtain a monophyletic clade with six sections. Plantago section Hymenopsyllium is more closely related to section Gnaphaloides than to section Albicans . Plantago subgenus Bougueria is sister to subgenus Psyllium s.l. section Coronopus in Plantago subgenus Coronopus is subdivided in two series. Only some of the sections can be resolved into series. DNA variation within genus Plantago is high, a result that would not have been predicted on the basis of morphology, which is relatively stereotyped. If we calibrate a molecular clock based on the divergence of P. stauntoni , endemic to New Amsterdam in the southern Indian Ocean, we calculate the time of the split between Plantago and Aragoa to be 7.1 million years ago, which is congruent with the fossil record. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 323–338. 相似文献
18.
A phylogenetic analysis of the family Lemuridae was accomplished using multiple gene partitions and morphological characters. The results of the study suggest that several nodes in the lemurid phylogeny can be robustly resolved; however, the relationships of the species within the genus Eulemur are problematically nonrobust. The genus Varecia is strongly supported as the basal genus in the family. Hapalemur and Lemur catta are strongly supported as sister taxa and together are the sister group to the genus Eulemur. E. mongoz is the most basal species in the genus Eulemur. E. fulvus subspecies form a monophyletic group with three distinct lineages. E. coronatus is strongly supported as the sister taxon to E. macaco. The relationships of E. rubriventer, E. fulvus, and the E. macaco-E. coronatus pair are unresolved. Our combined molecular and morphological analysis demonstrates the lack of influence that morphology has on the simultaneous analysis tree when these two kinds of data are given equal weight. The effects of several extreme weighting schemes (removal of transitions and of third positions in protein-coding regions) and maximum-likelihood analysis were also explored. We suggest that these other forms of inference add little to resolving the problematic relationships of the species in the genus Eulemur. 相似文献
19.
Entomological Review - The following six new species of the genus Thinodromus Kraatz, 1857, closely related to Th. (Amisammus) ripicola (Cameron, 1941) and Th. (A.) latus Gildenkov, 2003, are... 相似文献
20.
Phylogenetics of some Enchytraeidae (Annelida: Oligochaeta): A preliminary investigation of relationships to the Haplotaxidae 总被引:2,自引:2,他引:0
Kathryn A. Coastes 《Hydrobiologia》1987,155(1):91-106
In phylogenetic considerations of the Oligochaeta and the family Enchytraeidae, Propappus has been considered the ancestral or even the archetypal enchytraeid genus. Three nominal species are presently included in Propappus Michaelsen, 1905, P. volki Michaelsen, 1916, P. arhyncotus Sokolskaja, 1972, and the type species of the genus, P. glandulosus Michaelsen, 1905. Examination of type material of P. glandulosus and P. volki, as well as other material of the latter, showed that these species have a single pair of testes in segment XI and a single pair of ovaries in segment XIII. According to current classifications of the Oligochaeta, these species of Propappus cannot be retained in the Enchytraeidae. A phylogenetic analysis including two species of Propappus and 29 species of Haplotaxidae suggest a sister group relationship between Propappus and some Enchytraeidae and Haplotaxidae. 相似文献