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1.
Teeth from specified members of the two suborders of Late Cretaceous Multituberculata and two Late Cretaceous therians were studied. The enamel was prismatic on all teeth. In the therian representatives and the representatives of the suborder Ptilodontoidea of the Multituberculata, the prism diameters and densities per unit area were similar to those of recent mammals. In the representatives of the suborder Taeniolabidoidea the prisms were very large and their density per unit area was 5 to 8 times lower than in recent mammals. It is suggested that gigantoprismatic enamel is a characteristic of Taeniolabidoidea and could be used as a taxonomic criterion in multituberculate systematics.  相似文献   

2.
Multituberculates developed a very complex masticatory apparatus during their long evolutionary history from the Jurassic to the Paleogene. Besides their rodent-like elongated incisors and diastemata, Cenozoic cimolodont Multituberculata display masticatory movements involving two distinct cycles in the mastication. An orthal slicing-crushing cycle associated with an enlarged lower fourth premolar precedes a palinal grinding cycle linked to upper molars with three longitudinal rows of cusps. With their plesiomorphic lower premolars and upper molars, the Late Jurassic/Early Cretaceous multituberculate family Paulchoffatiidae can provide the key for the understanding of the origin of the complex mastication of the Cimolodonta. Using for the first time propagation phase contrast Synchrotron X-Ray microtomography to perform both microwear and topographic analyses in order to characterize the mastication of Paulchoffatiidae, we digitized dental material from the Late Jurassic of the Guimarota Coal Mine (Leiria, Portugal) at the European Synchrotron Facility (Grenoble, France). Mastication in Paulchoffatiidae is characterized by a palinal grinding cycle. In contrast to Cimolodonta, no evidence of an orthal slicing-crushing cycle has been observed: the lower premolars mainly have a grinding function like the molars as they do exhibit buccal attrition facets bearing longitudinal striations. Nevertheless, the slightly oblique striations observed on the mesial part of the paulchoffatiid lower premolars possibly presage the orthal phase of the Cimolodonta. Our topographic analysis indicates that a strong relationship between individual cusp shape and direction of chewing is emphasized in rodents and rodent-like Mammaliamorpha such as Cimolodonta and Tritylodonta. Surprisingly, this relationship is not evident in Paulchoffatiidae. This unexpected result can be explained by the non-involvement in the attrition of many premolar cusps in Paulchoffatiidae, as indicated by our microwear analysis. The stronger the attrition, the more the direction of the masticatory movements influences the cusp morphology in Mammaliamorpha.  相似文献   

3.
The phylogenetic relationships among characids are complex with many genera remaining of uncertain systematic position inside the family. The genus Hollandichthys is one of these problematic genera. It has been considered as incertae sedis inside this family until two recently published phylogenies, one morphological and one molecular, arrived at alternative hypothesizes as to the relationships of Hollandichthys with Pseudochalceus or Rachoviscus, respectively. In this paper, we infer the phylogenetic relations of these taxa based on five genes (three mitochondrial - COI, ND2 and 16S; and two nuclear - Sia and Trop), totaling up to 2719 bp. The 41 analyzed species in the Characidae include four incertae sedis characid taxa once hypothesized as related to Hollandichthys, but never analyzed in a single phylogeny (Rachoviscus, Pseudochalceus, Nematocharax and Hyphessobrycon uruguayensis). Here we propose Rachoviscus as the sister-group of Hollandichthys, grouped in the large clade C previously defined, along with the remaining incertae sedis taxa studied here. In addition, we support the evidence that insemination evolved independently at least three times in the Characidae.  相似文献   

4.
We present a phylogenetic hypothesis of the anuran clade Terrarana based on partial sequences of nuclear (Tyr and RAG1) and mitochondrial (12S, tRNA-Val, and 16S) genes, testing the monophyly of Ischnocnema and its species series. We performed maximum parsimony, maximum likelihood, and Bayesian inference analyses on 364 terminals: 11 outgroup terminals and 353 ingroup Terrarana terminals, including 139 Ischnocnema terminals (accounting for 29 of the 35 named Ischnocnema species) and 214 other Terrarana terminals within the families Brachycephalidae, Ceuthomantidae, Craugastoridae, and Eleutherodactylidae. Different optimality criteria produced similar results and mostly recovered the currently accepted families and genera. According to these topologies, Ischnocnema is not a monophyletic group. We propose new combinations for three species, relocating them to Pristimantis, and render Eleutherodactylus bilineatus Bokermann, 1975 incertae sedis status within Holoadeninae. The rearrangements in Ischnocnema place it outside the northernmost Brazilian Atlantic rainforest, where the fauna of Terrarana comprises typical Amazonian genera.  相似文献   

5.
Using shape data derived from the externa] body morphometry of esocoid fishes in which the effects of size were standardized, a close relationship of Umbra and Novumbra is supported. Dallia is provisionally associated with these but some data contradicted this. Esox is distantly associated with all of these. Thus the appropriate systematic classification for this group is: suborder Esocoidei; family Esocidae (five species in one genus— Esox ), family Umbridae (four species in two genera— Umbra and Novumbra ), and, incertae sedis Dallia (one or perhaps two species).  相似文献   

6.
黄晨  赵洪海  宋雯雯  梁晨 《菌物学报》2018,37(8):1006-1015
为揭示燕麦孢囊线虫孢囊定殖菌物的多样性,从青岛市选择3个罹患燕麦孢囊线虫病的冬小麦地,在返青期至成熟期,定时采集小麦根际燕麦孢囊线虫病土样,采用孢囊刺破法、单孢分离法或单菌丝分离法对定殖菌物进行分离纯化,并对定殖菌物进行形态鉴定和分子鉴定以及多样性分析。结果表明,从3个地点分离得到1 072个菌株,这些菌株归属于19目(含3个未定目)28科(含10个未定科)35属(含3个未定属),其中轮枝孢属Verticillium的相对多度最高,为25.2%,是优势属;镰孢菌属Fusarium、黑团孢属Periconia及链格孢属Alternaria的相对多度分别为14.9%、13.5%及13.4%。示范园样品的Margalef’s丰富度指数,Shannon-Wiener多样性指数及Pielou均匀度指数均最高,分别为4.30、2.516及0.755;家属区样品的Margalef’s丰富度指数最低,为3.18;而葛家屯样品的Shannon-Wiener多样性指数和Pielou均匀度指数最低,分别为2.077和0.654。3个地点定殖菌物群落组成的Jaccard相似性指数在0.486-0.607之间。  相似文献   

7.
Three of the subgenera in the sipunculan genus Phascolosoma are reviewed, based on examination of type material. The presumed difference between the subgenera Antillesoma and Rueppellisoma (number of retractor muscles) is shown to be invalid and the taxa are therefore synonymous. The 15 species are either considered junior synonyms of P. antillarum (eight), transferred to other species or genera (six), or considered incertae sedis (one). Phascolosoma antillarum is redescribed. Of the eight species in the subgenus Satonus, only P. pectinatum remains valid: the others are considered either to belong to other taxa (four) or to be incertae sedis (three).  相似文献   

8.
We propose the separation of Onslowia and Verosphacella from the Choristocarpaceae and from the Sphacelariales based on comparisons of DNA sequences of rbc L and nrRNA genes and morphological considerations. The new family Onslowiaceae is created to include these two genera. The families Choristocarpaceae and Onslowiaceae are considered incertae sedis.  相似文献   

9.
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   

10.
中国中、新生代大植物化石新属索引(1865-1990)   总被引:1,自引:1,他引:0  
吴向午 《古生物学报》1993,32(4):495-524
系统地检索1865-1990年的古植物文献,搜录了根据中国材料建立的中、新生代化石属113个,分属于蕨类植物门和种子植物门等.  相似文献   

11.
The rove beetle subtribe Xanthopygina (Coleoptera: Staphylinidae: Staphylininae: Staphylinini) is a species‐rich group of 27 neotropical genera that contains some of the largest and most brightly coloured of all staphylinid beetles. The monophyly of the subtribe has never been tested before, using a large dataset of taxa and genes. Bayesian and maximum likelihood analyses are used on individual genes (COI, 28S rDNA, wingless, arginine kinase, CAD and topoisomerase I) and the partitioned concatenated dataset to test for monophyly and examine the relationships among Xanthopygina genera. Xanthopygina (excluding Philothalpus) are shown to be a monophyletic group with strong support values. The genus Philothalpus is removed from Xanthopygina and placed in the tribe Staphylinini as incertae sedis. Four distinct clades of Xanthopygina genera are recognized. The origin of Xanthopygina is hypothesized to be in the Late Cretaceous or later and the origin of myrmecophilous adaptations is discussed.  相似文献   

12.
Phylogenetic relations among tanaidacean genera within ‘Akanthophoreinae’ are addressed using computer-assisted parsimony methods. The morphology-based analysis includes 10 well-defined and described genera: Araphura, Chauliopleona, Collettea, Paragathotanais, Metagathotanais, Paraleptognathia, Paranarthrura, Portaratrum, and Tanaella in Tanaidomorpha, and Glabroapseudes in Apseudomorpha as the outgroup. Chauliopleona and Paraleptognathia form a monophylum; Portaratrum cannot be placed in any known family. These three genera are considered as incertae sedis. The analysis does not support the monophyly of ‘Akanthophoreinae’, and further questions the monophyly of Tanaellidae.  相似文献   

13.
Abstract— A matrix of 41 Embiid taxa (representing the 8 formally recognized families of the Order) and 36 characters were cladistically analysed as a first attempt for understanding the higher classification of the Order Embioptera. The resulting trees were rooted with Clothodidae as the sister group of the other Embioptera. The results suggest that the current classification contains several artificial groups. With the rooting used, only Anisembiidae and Australembiidae are monophyletic. Embiidae is polyphyletic, as Australembiidae+ Notoligotomidae, Enveja (incertae sedis) and Oligotomidae+Teratembiidae appear within Embiidae, and the "embiid" Microembia appears within Notoligotomidae. Oligotomidae is paraphyletic in terms of Teratembiidae. Four of the genera included in the analysis are paraphyletic: Mesembia, Chelicerca (in terms of Dactylocerca and Pelorembia ), Aposthonia (in terms of Oligotoma ), and Metoligotoma (in terms of Australembia ). Pelorembia and Dactylocerca are synonymized with Chelicerca .  相似文献   

14.
A morphologically based cladistic analysis of 40 genera included within the Trichostrongyloidea (Amidostomatidae, Dromaeostrongylidae and Trichostrongylidae) is proposed. Two genera were used as outgroups, one from the Strongylina and the other from the Ancylostomatina. Seven genera do not appear in the matrix because some significant morphological characters remain unknown for these genera. Nonetheless, except for Moguranema which is excluded as incertae sedis, a likely systematic position could be assigned to them based on the morphological characters that are known. The classification which best fits the consensus tree is composed of three families. In adding the genera not included in the tree, we obtain: (i) Trichostrongylidae with three sub-families, Amidostomatinae (four genera), Filarinematinae (three genera) and Trichostrongylinae (five genera); (ii) Haemonchidae with two sub-families: Ostertagiinae (eight genera) and Haemonchinae (five genera); (iii) Cooperiidae with three sub-families: Libyostrongylinae (five genera), Obeliscoidinae n. subfam. (five genera) and Cooperiinae (ten genera). Dromaeostrongylus and Ortleppstrongylus, whose females have a caudal spine, are excluded from the Trichostrongyloidea and are placed in the Molineoidea. The hypotheses relating to the evolutionary history of the Trichostrongyloidea are: the origin of the superfamily could have occurred during the upper Cretaceous period. The two most ancient sub-families (Amidostomatinae and Filarinematinae) would be of Gwondwanan origin and evolved during the Paleocene period within Neotropical aquatic birds and within the Australian marsupials. The Trichostrongylinae would have arisen during the Eocene period within birds and then adapted to diverse archaic mammals in the Neotropical region on one hand and in the Nearctic region, on the other hand and lastly adapted to the Lagomorpha and subsequently to the Ruminantia. In both families originating from the Trichostrongylidae, the adaptation to the Lagomorpha may have taken place during the Oligocene but in a different way. In the Haemonchidae, the Ostertagiinae may have passed directly from the Neartic region to Europe. In the Cooperiidae, the adaptation to Lagomorpha may have occurred either within the Libyostrongylinae which may have remained in the Ethiopian region since the Paleocene, or, more likely, by the passage of the Obeliscoidinae from the Nearctic region to the Asian, through the Bering strait. In all cases, the adaptation of the Trichostrongyloidea of Lagomorpha to Ruminants apparently took place during the Miocene, mainly in the Palearctic and the Ethiopian regions.  相似文献   

15.
1988年,贵州省博物馆对桐梓岩灰洞的支洞进行了最后一次发掘。2014年,在洞内第四层堆积物中鉴定出逾2000件的动物牙齿化石,以及一枚古人类上颊齿(编号:TZ-1)。1991年,铀系法测定这些次生堆积物的沉积年代约为距今24万年。本文运用高精度CT(巴黎自然历史博物馆)对TZ-1的釉质齿质界面(EDJ)和牙髓腔几何形态进行了分析。TZ-1的冠面形态有如下特征:次尖小且在远中舌侧不发育,咀嚼面轮廓呈四边形,颊舌径稍大过近中远中径,原尖舌侧齿带发育,齿尖从大到小依次为原尖、后尖、前尖和次尖。TZ-1牙髓腔的髓角与其釉质齿质界面以及釉质表面的形态都具有相关性。TZ-1的形态与M1虽有相似之处,但完全不同于1983年出土于同一层位的另两颗M1;其应被鉴定为dm2,并可被归入中中更新世的中国直立人支系。岩灰洞上臼齿PA 875的形态与建始龙骨洞PA 1279和周口店直立人等古老型直立人相似。岩灰洞另一枚刚萌发的臼齿PA 874具有凸出的次尖和长菱形的外廓,接近于爪哇型直立人Sangiran NG 91-G10;这也是智人和尼安德特人的共有衍征。但PA 874的冠面仍保留了亚洲型的齿带,因而被归入人属未定种。因出土自次生堆积,岩灰洞的三种古人类类型未必曾同时并存,但却揭示了华南地区人类演化进程中的多样面貌。  相似文献   

16.
Caucasichthys kumaensis gen. et sp. nov., a representative of a new monotypic perciform family Caucasichthyidae, from the Middle Eocene (Bartonian, Kuma Horizon) of the North Caucasus (Gorny Luch locality) is described. The new family is characterized by elongated body, strong preopercular spine in adults, absence of supraneurals, large pelvic fins, long caudal peduncle, and anal fin longer at the base than soft dorsal fin. Scales vary from cycloid to spinoid on different parts of the body. Caucasichthys shares a number of apomorphic features with members of certain percoid families, most notably the Priacanthidae. However, because of its unique combination of features, the new family cannot be properly placed within any existing perciform suborder and it is placed incertae sedis among the Perciformes.  相似文献   

17.
The possession of wings and ability to fly are a unifying character of higher insects, but secondary loss of wings is widespread. Within the bushcrickets, the subfamily Phaneropterinae (Orthoptera: Tettigonioidea) comprises more than 2000 predominantly long-winged species in the tropics. However, the roughly 300 European representatives are mainly short-winged. The systematics of these radiations have been unclear, leading to their unreliable formal treatment, which has hindered analysis of the evolutionary patterns of flight loss. A molecular phylogeny is presented for 42 short-winged species and members of all European long-winged genera based on the combined data from three nuclear gene sequences (18S, H3, ITS2). We found four phylogenetic lineages: (i) the first included the short-wing species of the genus Odontura; (ii) a further branch is represented by the South-American short-winged Cohnia andeana; (iii) an assemblage of long-wing taxa with a deep branching pattern includes the members of the tribes Acrometopini, Ducetiini, Phaneropterini, and Tylopsidini; (iv) a large group contained all short-winged taxa of the tribe Barbitistini. Phaneropterinae flightlessness originated twice in the Western Palaearctic, with a number of mainly allo- and parapatrically distributed species of the Barbistini in Southeastern Europe, and the Middle East and a limited number of Odontura species in Northern Africa and Southwestern Europe. Both short-winged lineages are well separated, which makes it necessary to restrict the tribe Odonturini to the West-Palaearctic genus Odontura. Other flightless genera previously included in the Odonturini are placed as incertae sedis until their phylogenetic position can be established.  相似文献   

18.
A hypothesis (CI=57.3%) on the evolutionary relationships of families comprising the class Monogenoidea is proposed based on 141 character states in 47 homologous series and employing phylogenetic systematics. Based on the analysis, three subclasses, the Polyonchoinea, Polystomatoinea and Oligonchoinea, are recognised. The analysis supports independent origins of the Montchadskyellidae within the Polyonchoinea and of the Neodactylodiscidae and Amphibdellatidae within the order Dactylogyridea (Polyonchoinea); the suborder Montchadskyellinea is raised to ordinal status and new suborders Neodactylodiscinea and Amphibdellatinea are proposed to reflect these origins. The Gyrodactylidea (Polyonchoinea) is supported by three synapomorphies and comprises the Gyrodactylidae, Anoplodiscidae, Tetraonchoididae and Bothitrematidae. The analysis supports recognition of the Polystomatoinea comprising Polystomatidae and Sphyranuridae. Evolutionary relationships within the Oligonchoinea indicate independent origins of three ordinal taxa, the Chimaericolidea (monotypic), Diclybothriidea (including Diclybothriidae and Hexabothriidae) and Mazocraeidea (with five suborders). The suborder Mazocraeinea comprises the Plectanocotylidae, Mazocraeidae and Mazoplectidae, and is characterised by two synapomorphies. The suborder Gastrocotylinea, characterised by presence of accessory sclerites in the haptoral sucker, is divided into two infraorders, the monotypic Anthocotylina infraorder novum and Gastrocotylina. Two superfamilies of the Gastrocotylina are recognised, the Protomicrocotyloidea and Gastrocotyloidea; the Pseudodiclidophoridae is considered incertae sedis within the Gastrocotylina. The suborder Discocotylinea comprises the Discocotylidae, Octomacridae and Diplozoidae and is supported by four synapomorphies. The monotypic Hexostomatinea suborder novum is proposed to reflect an independent origin of the Hexostomatidae within the Mazocraeidea. The terminal suborder Microcotylinea comprises four superfamilies, the Microcotyloidea, Allopyragraphoroidea, Diclidophoroidea and Pyragraphoroidea. The analysis supports incorporation of the Pterinotrematidae in the Pyragraphoroidea and rejection of the monotypic order Pterinotrematidea. The following taxa are also rejected for reasons of paraphyly and/or polyphyly: Articulonchoinea, Bothriocotylea, Eucotylea, Monoaxonematidea, Tetraonchidea, Gotocotyloidea, Anchorophoridae and Macrovalvitrematidae. The Sundanonchidae, Iagotrematidae and Microbothriidae were not included in the analysis because of lack of pertinent information regarding character states.  相似文献   

19.
New nymphs of the gryllones insects (Insecta; Gryllones) Iblatta attrepida gen. et sp. nov. (Eoblattida incertae sedis) and Tshekardushka artenatis gen. et sp. nov. (Reculida incertae sedis) from the Lower Permian Chekarda locality (Kungurian Stage of Russia) are described. The nymph of Czekardia blattoides Martynov, 1940 (Eoblattida incertae sedis) from Chekarda is redescribed.  相似文献   

20.
Abstract. The genus Microdonacia Blackburn is revised and its systematic position considered. Ten species are treated, seven of which are new ( bidentata, eucryphiae, grevitteae, incurva, octodentata, pilosa, pomaderris ), and lectotypes are designated for two species. Four of the new species are placed in Tantawangalo subgen.n. Microdonacia is compared with the genera Cassena Weise, Licyllus Jacoby and Orthaltica Crotch. The sister-group for Microdonacia is identified as Orthaltica and these genera are placed incertae sedis in the Galerucinae, as used in the sense of Crowson (1967). The proposed phylogeny of the species is illustrated on a cladogram.  相似文献   

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