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1.
The anatomy of the anabantoid fish Luciocephalus is reinvestigated and the ontogeny of certain character complexes is described for the first time. Luciocephalus possesses the following previously unrecognized or equivocally interpreted anatomical characters: a clearly separate ectopterygoid bone, pharyngeal processes of the basioccipital, a toothless pharyngeal process of the parasphenoid, an infrapharyngobranchial I and an endoskeletal mental ossification. In addition, aspects of the ontogeny of the hyopalatine arch in the belontiids Belontia, Trichogaster and Ctenops are described. Species of these three genera all possess an ectopterygoid bone previously thought to be lacking in the family Belontiidae. The significance of the results for reconstructing interrelationships of the anabantoid families and the phylogenetic position of Luciocephalus is discussed. A revised hypothesis of anabantoid intrarelationships is presented. Four synapomorphic characters indicate that Luciocephalus is more closely related to the Belontiidae (including Osphronemus) rather than forming the sister group of all other anabantoids.  相似文献   

2.
An osteological study of representatives of the seven genera of creediids supports the view that the family is monophyletic. New diagnostic characters include the form of the pelvis, mesopterygoid, and ectopterygoid. Characters are given which distinguish members of Creediidae from other fishes. Three lineages of creediids are recognized on the basis of osteological and external characters, withSchizochirus insolens, the least derived and the most distinctive species, comprising the first lineage, the species ofCreedia the second, and those ofLinmichthys, Tewara,Crystallodytes, Chalixodytes, andApodocreedia the third.  相似文献   

3.
A principal components analysis was performed on 20 measurements of the ectopterygoids of 85 colubroid snakes. This sample encompassed all the shape variation previously recognized in the ectopterygoid of colubroids. Simple proportions which correlate with the first two principal component axes are: relative ectopterygoid length with the first and five measures of absolute or relative head shape with the second. Using these simple proportions colubroid ectopterygoids can be sorted into four shape classes each concordant with a taxonomic grouping: relatively long with broad notched head—Crotalinac; relatively long with narrow, flat head—Viperinae; relatively short with broad, notched head—Colubridae; and relatively short with narrow, flat head—Elapidae. This concordance has an error of about 1000. We propose that these shape classes reflect phylogenetically old and conservative functional differences in the palatomaxillary complexes of the four taxonomic groupings. Other aspects of ectopterygoid shape are described and provisional character state phylogenies for some aspects of the ectopterygoid are presented. Finally, the bearing of our data on the systematics of aparallactines, micrurines, sea snakes, Azemiops and certain other genera are discussed.  相似文献   

4.
Trophic specialization of the larvae of Oecophorid moths from the Palaearctic Region is investigated. The former family Oecophoridae (sensu lato) is presently considered a polyphyletic group and is divided into the separate families Oecophoridae sensu stricto (with subfamilies Deuterogoniinae, Oecophorinae and Pleurotinae), Chimabachidae, Amphisbatidae and Depressariidae. Xyloryctidae, Stathmopodidae, Ethmiidae and Autostichidae are also considered as separate families. In these taxa, two main modes of feeding occur: on dead plants and on living plants. The first mode is inhered in Oecophoridae (in subfamily Pleurotinae both the modes are known) and Autostichidae. The family Amphisbatidae occupies an intermediate position as the larvae of Amphisbatini use dead leaves, whereas the larvae of Fuchsiini and Hypercalliini use green plants. The rest of the families associate with living plants. Trophic specialization in the families formerly included in Oecophoridae mostly corresponds to the taxonomic division based mainly on the morphological characters, although some exceptions are known, e. g. feeding of larvae of Carcina quercana (Oecophoridae, Oecophorinae, Carcinini) on living leaves.  相似文献   

5.
A cladistic analysis of Lophopidae was performed, using 73 observed morphological characters and 41 taxa. This analysis involved 36 genera belonging to the Lophopidae family and 5 outgroups. For a better understanding of the selected characters some illustrations are provided. The most parsimonious cladograms obtained show that the Lophopidae cannot be considered as a monophyletic lineage unless two genera are withdrawn from this family: Hesticus Walker, 1862, and Silvanana Metcalf, 1947. The systematic position of these two genera remains uncertain. They cannot yet be included in another family of Fulgoromorpha. A cladistic analysis of each of the 19 remaining Fulgoromorphan families must be performed first. A new family could be created for these two genera, but not before we are sure that these two genera are in no way members of an existing family. The outgroup problem is discussed. The monophyletic lineage represented by the Lophopidae can be divided into four natural groups: Carriona+, Makota+, Sarebasa+, and Bisma+. When a cladistic analysis is completed using a data matrix without characters linked to females, the cladogram obtained presents a disrupted basal resolution. Female characters appear to bring a phylogenetic signal important basally in the evolution of the Lophopidae but also apically, directly between the relationships of some genera. A similar analysis, using a matrix without characters linked to males, provides a phylogeny disrupted between the groups that form the Lophopidae and in the basal resolution in these groups. The respective impacts of the genitalic characters are discussed in relation to sexual selection conflict.  相似文献   

6.
贵州中三叠世早期幻龙属(Nothosaurus)一新种   总被引:3,自引:0,他引:3  
作为三叠纪海生爬行动物的重要分子,幻龙属化石主要发现于欧洲、中东和中国西南地区的中三叠世海相地层,且主要集中分布于安尼期晚期和拉丁期晚期(Edinger,1921;Haas,1980;Rieppel,2000)。我国目前已报道的幻龙属化石有两种:杨氏幻龙(Li and Rieppel,2004)和幻龙属未定种(Rieppel,1998),它们均产于贵州省兴义地区的法郎组竹杆坡段,时代为中三叠世拉丁期。最近在贵州省盘县地区关岭组Ⅱ段地层中也发现了数量较多的幻龙骨骼化石,证明中三叠世早期东特提斯区同样生存着幻龙类。鉴于标本的骨骼特征与已知的幻龙属种相比存在一定的差异,因此本文建立一新种Nothosaurus rostellatus sp.nov.(小吻幻龙)。新种的个体在幻龙属种中为中等(头骨中线长210~320mm);吻部短而小,具4个前颌骨獠齿,紧随其后是第5个明显较小的前颌齿;一对上颌骨犬齿之前有6~9个小型上颌齿;眼窝较大,卵圆形,位置相对靠前;内鼻孔的后缘由腭骨构成,具内鼻槽;外翼骨形成腹向凸缘;下颌具冠状突;背椎神经棘较低,背肋肩部明显加厚。N.rostellatus与其他已知种的主要区别特征是吻部形态和比例。新种的吻部较小,长略大于宽,前端钝圆,基部明显收缩,其吻部长度(从吻端至外鼻孔前端的距离)仅占其头骨中线长度的1/6~1/7,而其他种一般占1/4~1/5,具有细长吻部的N.haasi甚至接近1/3。此外,新种吻端-上颞孔前缘距离与吻端-外鼻孔前缘距离的比值也明显高于其他种。N.rostellatus区别于其他幻龙种的另一主要特征是上颌骨牙齿的数目和排列。在已知的幻龙属种中,很少有一对上颌犬齿前的上颌齿数超过5个者。新种正型标本ⅣPPⅤ14294在一对上颌犬齿前具有6个小型锥状上颌齿,它们大小相等,指向腹方。副型标本ⅣPPⅤ14301在一对上颌犬齿前具有9个小型锥状上颌齿。在已知的Nothosaurus中,新种与N.youngi Li & Rieppel,2004和N.marchicus Koken,1893无论是个体大小还是头骨形态均比较接近,如具有相对短而宽的吻部和较短的上颌齿列、相似的鼻骨形态等,与其他种相差较大,因此这里仅对新种与此二种之间的异同做简要的介绍。从头骨的一些具体形态特征看,N.rostellatus的鼻骨后侧方与前额骨相连,阻隔了额骨和上颌骨,该特征与N.youngi相同而不同于N.marchicus,后者鼻骨受额骨与上颌骨的阻隔,不与前额骨相连。如果不考虑鳞骨的外侧分支的宽度,Ⅴ14294和Ⅴ14301与N.youngi的头骨的最宽处均位于轭骨的后端位置,且其宽度为吻部宽度的2.6~3.5倍(其中N.youngi为2.6倍,Ⅴ14294为3倍,Ⅴ14301为3.5倍),而N.marchicus的最宽处位于头骨后部鳞骨的分支处,其轭骨后缘处头骨宽度为吻部宽度的2~2.8倍(Rieppel and Wild,1996,fig.36,41)。此外,N.rostellatus外翼骨形成腹向突起和下颌具冠状突的特点也与N.youngi相同,N.marchicus不具有该特征。另一方面,N.rostellatus的枕部特征则与N.marchicus接近而不同于N.youngi。新种的枕部内凹,枕骨侧边的后耳骨等向后侧部延伸,下颌关节在头骨后部位于枕髁之后,该枕部特征与N.marchicus一致。N.youngi的下颌关节与枕髁基本位于一个平面内,因此枕部未形成明显的内凹。新种的眼眶与上颞孔之间的距离相对较宽,其中V 14294眼眶与上颞孔之间的距离与外鼻孔与眼眶之间的距离接近相等,而V 14301眼眶与上颞孔之间的距离大于外鼻孔与眼眶之间的距离。此特征也与N.marchicus相同而不同于N.youngi,前者眼眶与上颞孔之间的距离与外鼻孔与眼眶之间的距离相等,后者的眶后弓很窄,其眼眶与上颞孔之间的距离小于外鼻孔与眼眶之间的距离的1/2。N.rostellatus鼻骨的左右两前突分别伸至两外鼻孔的前缘内侧,位置与N.marchicus相同,而N.youngi鼻骨前突仅伸至外鼻孔内侧缘的中部。N.rostellatus前颌骨的背突向后伸至外鼻孔后缘之后,接近鼻骨的后缘,而N.youngi仅伸至外鼻孔后缘中间部位。除前文所述新种两个主要鉴定特征外,N.rostellatus又以具有内鼻槽,翼骨前伸至内鼻槽附近等特征与该已知二种相区别。此外,新种前颌骨具外侧支突起,其他种该特征多不明显,如N.jagisteus不存在前颌骨外侧支突起,其前颌骨在外鼻孔的前外侧缘沿前外侧方向与上颌骨相交(Rieppel,2001)。从地理分布和地层层位看,N.marchicus主要分布于欧洲中部的中三叠统安尼阶,而N.youngi则分布于我国贵州南部的中三叠统拉丁阶。本文描述的化石产于贵州南部关岭组Ⅱ段,其时代应相当于中三叠世晚安尼期。N.rostellatus与分布于欧洲的同时期的幻龙N.marchicus以及与在其后约7~8Ma相邻地区出现的M.youngi的亲缘关系的远近可能还需要更深入的研究来证实。  相似文献   

7.
昆都仑鱼(Kuntulunia)的新材料及其系统位置的讨论   总被引:2,自引:2,他引:0  
本文根据对宁夏六盘山群马东山组的长鳍昆都仑鱼(Kuntulunia longipterus, Liu, Ma et Liu 1982)的新材料的研究,对其形态特征做了一些补充和订正。在此基础上,笔者支持刘宪亭等人将昆都仑鱼归入华夏鱼科(Huashiidae)及华夏鱼科归入骨舌鱼类的观点。并且认为华夏鱼类代表了一新的亚目——华夏鱼亚目(Huashioidei subordo. nov.)。  相似文献   

8.
本文对过去认为与十齿花属近缘的科,属的形态,木材解剖,花粉形态等方面的特征进行了较全面的比较研究。结果支持最初作者置于卫矛科的意见,并建立十齿花亚科,置于卫矛亚科和雷公藤亚科之间。滇西北产者订为一所种。  相似文献   

9.
<正>Based on abundant new materials of Peipiaosteus pani, many features are newly described, they include: rostral bones, circumorbital series, the ectopterygoid process of the maxilla, quadratojugals, branchial toothplates, axial skeleton, fulcra and epiaxial fin-rays on the caudal fin. A few other features such as the hyomandibula and branchiostegal are revised. The ontogenetic and taphonomic characters of Peipiaosteus indicate that it probably assumed a habit of migration like its extant descendants. A review of the differences between P. pani and P. fengnengensis shows that all the differences except the dorsal and anal fin-ray numbers proposed by Bai (1983) are not true or remain uncertain. Through comparison, stichopterus is included in the revised family: Peipiaosteidae. Finally, a review of the phylogeny of Acipenseriformes results in a conclusion of Peipiaosteidae and Acipenseridae as sister groups.  相似文献   

10.
We have identified and sequenced two members of a chicken middle repetitive DNA sequence family. By reassociation kinetics, members of this family (termed CRl) are estimated to be present in 1500-7000 copies per chicken haploid genome. The first family member sequenced (CRlUla) is located approximately 2 kb upstream from the previously cloned chicken Ul RNA gene. The second CRl sequence (CRl)Va) is located approximately 12 kb downstream from the 3' end of the chicken ovalbumin gene. The region of homology between these two sequences extends over a region of approximately 160 base pairs. In each case, the 160 base pair region is flanked by imperfect, but homologous, short direct repeats 10-15 base pairs in length. When the CRl sequences are compared with mammalian ubiquitous interspersed repetitive DNA sequences (human Alu and Mouse Bl families), several regions of extensive homology are evident. In addition, the short nucleotide sequence CAGCCTGG which is completely conserved in ubiquitous repetitive sequence families from several mammalian species is also conserved at a homologous position in the chicken sequences. These data imply that at least certain aspects of the sequence and structure of these interspersed repeats must predate the avian-mammalian divergence. It seems that the CRl family may possibly represent an avian counterpart of the mammalian ubiquitous repeats.  相似文献   

11.
A phylogenetic analysis using characters from egg cases, larvae, pupae and adults was conducted; the outgroups included the beetle families Silphidae, Hydraenidae and Histeridae. Characters from the immature stages were obtained mostly from material reared in the laboratory, those from the adults were obtained from Hansen's generic revision for the superfamily. The results support the position of Hydraenidae within the Staphylinoidea, and not as part of Hydrophiloidea; Histeroidea is proposed as the sister group of Hydrophiloidea. At family level two clades are distinguished; the relationships within the first clade are ((Georissidae Epimetopidae) Helophoridae), those within the second are ((Hydrophilidae Spercheidae) Hydrochidae). Larval characters were most informative at the base of the tree, especially those associated with the spiracular atrium; adult characters were most informative at the apex of the tree.  相似文献   

12.
Phylogenetic relationships among families of the Scaphopoda (Mollusca)   总被引:1,自引:0,他引:1  
Phylogenetic relationships among families in the molluscan class Scaphopoda were analysed using morphological characters and cladistic parsimony methods. A maximum parsimony analysis of 34 discrete characters, treated as unordered and equally weighted, from nine ingroup terminal taxa produced a single most parsimonious tree; supplementary analyses of tree length frequency distribution and Bremer support indices indicate a strong phylogenetic signal from the data and moderate to minimally supported clades. The traditional major division of the class, the orders Dentaliida and Gadilida, is supported as both taxa are confirmed as monophyletic clades. Within the Dentaliida, two clades are recognized, the first comprised of the families Dentaliidae and Fustiariidae, the second of the Rhabdidae and Calliodentaliidae; together, these groups comprise a third clade, which has the Gadilinidae as sister. Within the Gadilida, a nested series of relationships is found among [Entalinidae, [Pulsellidae, [Wemersoniellidae, Gadilidae]]]. These results lend cladistic support to earlier hypotheses of shared common ancestry for some families, but are at variance with other previous hypotheses of evolution in the Scaphopoda. Furthermore, analysis of constituent Gadilinidae representatives provide evidence for paraphyly of this family. The relationships supported here provide a working hypothesis that the development of new characters and greater breadth of taxonomic sampling can test, with a suggested primary goal of establishing monophyly at the family level.  相似文献   

13.
Summary Hemophilia B is due to multiple molecular defects in the factor IX gene. Over 80% of mutations are single base substitutions. By amplification and direct sequencing, 51 single base substitutions were found in the transcribed sequence of the factor IX genes of patients from 50 distinct families with hemophilia B. These include 30 mutations in 29 families not previously reported by us; of these, 12 are novel, i.e., not previously published in other series. Of the 51 substitutions in our overall series 23 (45%) occurred as C-to-T or G-to-A transitions at 11 sites within CG dinucleotides. It is estimated that CG transitions occur from one to two orders of magnitude more frequently than mutations in nucleotides that are not within a CG pair. More than one family had identical defects for 6 of the CG mutations. At 4 of these sites, most patients had different haplotypes compatible with distinct mutations. Non-CG-type mutations occurred thoughout the coding regions with only one mutation in more than one family. The latter included 7 families with a 397 Ile-to-Thr defect that all share a rare haplotype, suggesting a common ancestor.  相似文献   

14.
15.
The family Asclepiadaceae (Dicotyledones) was created by Brown in 1810 by splitting in two the family Apocynaceae of Jussieu established in 1789. The morphological characters used to make this distinction were mainly palynological, such as presence of tetrads or pollinia and number and orientation of pollinia. Those characters, still used in higher taxonomic delimitation (families, subfamilies, and tribes), are here critically reexamined and compared to a molecular phylogeny obtained with one of the more variable plastid genes (matK) of 46 species in the order Gentianales. In this molecular phylogeny, Asclepiadaceae form a monophyletic group derived from within Apocynaceae. Each of the subfamilies of Asclepiadaceae is monophyletic and based on reliable palynological characters, but palynological characters are not useful to delimit tribes of the subfamily Asclepiadoideae. Based on the molecular data, these tribes have undergone parallelisms in several reproductive traits.  相似文献   

16.
The anatomy of the middle ear region of the skull is described for the families of the Avian orders Pelecaniformes and Ciconiiformes. Emphasis is placed on the foramina and paths of the nerves and blood vessels. The morphology of the basicranium and quadrate is also discussed. Comparative analyses of the characters are used to assess taxonomic conclusions.
Extant Pelecaniformes consist of six families, four of which are monogenic: Phaethontidae, Pelecanidae, Anhingidae and Fregatidae; one is composed of two genera: Sulidae; and the last has three genera: Phalacrocoracidae. Several years ago a relationship was suggested which would ally the Phaethontidae and the Fregatidae. While these families share several non middle ear characters the anatomy of the middle ear is not compatible with any particular relationship. Indeed, several obvious differences are described. The data presented here are consistent with the idea that the Phaethontidae and the Fregatidae each form a separate group of Pelecaniform birds, with the rest of the families forming a third group. Several differences in the middle ear region of the species of Anhingidae suggest that the family may be composed of two genera.
While sharing many Ciconiiform characters the Ciconiidae have been shown not to be as closely related to the Ardeidae as they are to other families of Ciconiiformes. In addition, evidence is presented to support the recent idea that the three species of ibis (I. ibis, I. cinereus and I. leucocephalus ) be united within the genus Mycteria. Also supported is the notion that Balaeniceps is Pelecaniform in character, and not Ciconiiform.  相似文献   

17.
《Ibis》1922,64(1):142-147
T he genus Zosterops is one which it is extremely difficult to place. It has external and superficial characters which would seem to ally it with many other families, but these are accompanied by so many other contradictory characters,—at least, in so far as our Oriental species are concerned,—that it appears advisable to place the genus in a family by itself.  相似文献   

18.
19.
Various interpretations of the holothurian system and phylogeny are critically reviewed and the main characters that form the basis of the existing systematics of this group are analyzed. A system of holothurians based on thorough analysis of their morphology and anatomy is proposed. Four subclasses are recognized in the class Holothuroidea: Arthrochirotacea, Synaptacea, Elpidiacea, and Holothuriacea. The subclass Arthrochirotacea includes the extinct Paleozoic order Arthrochirotida. The subclass Synaptacea includes the order Synaptida with two suborders and three families. The subclass Elpidiacea includes the order Elasipodida with four families. The subclass Holothuriacea includes four orders: Aspidochirotida with five families; Dendrochirotida with 15 families (14 extant and one extinct); Molpadiida with three families; Gephyrothuriida with one family and two genera Gephyrothuria and Hadalothuria. The order Gephyrothuriida is re-established. The order Dactylochirotida Pawson et Fell, 1965 is synonymized under the order Dendrochirotida. A new suborder Cucumariina and new family Mesothuriidae are described. The family Vaneyellidae is synonymized under the family Cucumariidae. Four subfamilies are classified as families: Cladolabidae, Sclerothyonidae, Monilipsolidae, and Thyonidiidae.  相似文献   

20.
Fifteen families of Anoplura are recognized and defined, one with two sub-families, and a key is provided for their identification. The included genera are listed for each family, together with the relevant type-species as well as the mammalian hosts. Phylogenetic relationships between the families are discussed, and an extensive historical review and analysis of the available taxonomic characters is presented.  相似文献   

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