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1.
The systematics of the order Tubulidentata is poorly known. Its phylogeny has never been thoroughly analysed and only a single review has ever been performed, which was over 30 years ago. This situation has hampered palaeoecological and palaeobiogeographical studies of these Neogene mammals. The present revision of the Orycteropodidae deals with the phylogeny and systematics of all African and Eurasian species over the last 20 Myr. The first comprehensive cladistic analysis of the family is presented here. The results of this analysis, based on 39 coded morphological characters, supplemented by non‐coded features taken from all over the skeleton, was used to reconstruct the phylogeny of the order Tubulidentata. Two distinct lineages within the genus Orycteropus are recognized and characterized. The new genus Amphiorycteropus is subsequently created, in order to harmonize taxonomy and phylogeny. The fossil genera Leptorycteropus and Myorycteropus are validated, bringing the number of genera in the order Tubulidentata to four. Moreover, within the family Orycteropodidae, the number of confirmed species is now 14. The outcome of this study allows us to propose a consistent palaeobiogeographical scenario for aardvarks. Finally, this revision represents the most comprehensive work on the evolutionary history of the order Tubulidentata to date, and provides a new framework for future studies. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 649–702.  相似文献   

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The neurocranial osteology of the giant monitor lizard Varanus (Megalania) prisca Owen, 1859 is described in detail for the first time. Optimization of neurocranial characters onto phylogenetic topologies for varanoids, including Lanthanotus, Heloderma, and Varanus species nests V. prisca within an Indo‐Australian clade of Varanus on the basis of characters of the otic capsule. A sister‐taxon relationship between V. prisca and Varanus komodoensis Ouwens, 1912 is proposed based on apomorphies of the crista prootica, fenestra vestibuli, occipital recess, and supraoccipital. These results support a monophyletic clade of giant monitors among Indo‐Australian species, and unambiguously synonymize Megalania with Varanus at both generic and subgeneric levels. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 445–457.  相似文献   

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The rich Deseadan fauna from the locality of Salla Luribay (Bolivia) documents the last occurrence of archaeohyracids, a poorly known group of small typotherian notoungulates. Exceptionally, archaeohyracid remains are extremely abundant in the Salla deposits and are assigned to a single new species Archaeohyrax suniensis sp. nov . The anatomy of the new taxon is presented and the ontogeny of the cheek teeth is described. Archaeohyrax patagonicus Ameghino, 1897 from the Deseadan of Patagonia is also redescribed and compared with the new Bolivian species. Additionally, juvenile teeth of Sallatherium altiplanense (Hegetotheriidae) are described because they provide crucial phylogenetic information for understanding the phylogeny of archaeohyracids. A cladistic analysis performed on archaeohyracids and hegetotheriids supports for the first time the existence of a clade of late archaeohyracids (post‐Mustersan), which is the sister taxon of all hegetotheriids. It also argues for the origin of mesotheriids within archaeohyracids and for the existence of a hegetotheriine clade. These conclusions fit well with temporal data known for each taxa. Nevertheless, the present analysis also underlines the fact that the lack of data concerning the cranial anatomy of many archaeohyracids (Eohyrax, Pseudhyrax, Archaeotypotherium, Protarchaeohyrax) weakens the phylogenetic signal. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 458–509.  相似文献   

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Fishes of the order Alepocephaliformes, slickheads and tubeshoulders, constitute a group of deep‐sea fishes poorly known in respect to most areas of their biology and systematics. Morphological studies have found alepocephaliform fishes to display a mosaic of synapomorphic and symplesiomorphic characters, resulting in great difficulties when attempting to resolve intra‐ and interrelationships. Molecular data recently added to the confusion by removing Alepocephaliformes from the Euteleostei and placed them as incertae sedis within the Otocephala. In the present study we attempt to further clarify relationships of Alepocephaliformes by adding newly determined whole mitogenome sequences from 19 alepocephaliforms in order to address 1) phylogenetic position of Alepocephaliformes within the Otocephala; and 2) intrarelationships of Alepocephaliformes. The present study includes 96 taxa of which 30 are alepocephaliforms and unambiguously aligned sequences were subjected to partitioned maximum likelihood and Bayesian analyses. Results from the present study support Alepocephaliformes as a genetically distinct otocephalan order as sister clade to Ostariophysi (mostly freshwater fishes comprising Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes and Gymnotiformes). The disputed family Bathylaconidae was found to be an artificial assemblage of the two genera Bathylaco and Herwigia, with the former as the sister group of the family Alepocephalidae and the latter nested within Alepocephalidae. Platytroctidae was found to be monophyletic as sister clade to the rest of Alepocephaliformes. Previously unrecognized clades within the family Alepocephalidae are presented and a clade comprising Alepocephalus, Conocara and Leptoderma was recovered as the most derived. As long as the current classification is being followed, the genera Alepocephalus, Bathytroctes, Conocara and Narcetes were all found non‐monophyletic. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 923–936.  相似文献   

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Although ratites have been studied in considerable detail, avian systematists have been unable to reach a consensus regarding their relationships. Morphological studies indicate a basal split separating Apterygidae from all other extant ratites, and a sister‐group relationship between Rheidae and Struthionidae. Molecular studies have provided evidence for the paraphyly of the Struthionidae and Rheidae, with respect to a clade of Australasian extant ratites. The position of the extinct Dinornithidae and Aepyornithidae also remains hotly debated. A novel pattern of diversification of ratites is presented herein. The phylogenetic analysis is based on 17 taxa and 129 morphological characters, including 77 new characters. The resultant tree yields a sister‐group relationship between New Zealand ratites (Apterygidae plus Dinornithidae) and all other ratites. Within this clade, the Aepyornithidae and Struthionidae are successive sister taxa to a new, strongly supported clade comprising the Rheidae, Dromaiidae, and Casuariidae. The link between South American and Australian biotas proposed here is congruent with numerous studies that have evidenced closely related taxa on opposite sides of the Southern Pacific. These repeated patterns of area relationships agree with current knowledge on Gondwana break‐up, which indicates that Australia and South America remained in contact across Antarctica until the earliest Tertiary. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 641–663.  相似文献   

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Pseudonaja is a clade of seven nominal species of elapid snakes distributed throughout Australia and in southern New Guinea. The species‐level systematics of this group is generally considered to be problematic. A recent phylogenetic analysis of mitochondrial DNA sequences for a geographically extensive series of Pseudonaja specimens revealed nine major clades, of which six largely coincide with nominal species (P. affinis, P. guttata, P. inframacula, P. ingrami, P. modesta and P. textilis). The three remaining clades are composed of specimens currently referred to P. nuchalis. This paper presents a multivariate analysis of 30 morphometric variables recorded for 220 specimens, representing the P. affinis, P. inframacula, P. textilis and three P. nuchalis clades (P. guttata, P. ingrami and P. modesta are well‐demarcated species and, accordingly, were not considered). The morphometric data readily separate these putative lineages, affording compelling evidence that they constitute evolutionary species. The names aspidorhyncha and mengdeni are resurrected for two of the three species presently recognized as P. nuchalis. These species, P. affinis, P. inframacula, P. nuchalis and P. textilis are redescribed. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 171–197.  相似文献   

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Twenty‐two chromosome counts are reported in 16 species, four subspecies and two varieties of the genus Centaurea. These are mostly Turkish local endemics of section Cheirolepis, a complicated group from the Eastern clade of the Jacea group. Twenty‐one reports are new. Prevalence of the basic chromosome number x = 9 among the eastern sections of the Jacea group is confirmed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 280–286.  相似文献   

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We report a nearly complete skeleton of a new species of stem roller (Aves, Coracii) from the early Eocene Green River Formation of North America. The new species is most closely related to two species‐depauperate lineages, Coraciidae (rollers) and Brachypteraciidae (ground rollers), that form a monophyletic crown clade (Coracioidea) with an exclusively Old World extant distribution. Phylogenetic analysis utilizing a matrix of 133 morphological characters and sequence data from three genes (RAG‐1, c‐myc, and ND2) identifies the new species as a stem member of the Coracii more closely related to the crown clade than the only previously identified New World taxon, Primobucco mcgrewi. The phylogenetic placement of the new species and Primobucco mcgrewiindicates a widespread northern hemisphere distribution in the Eocene with subsequent restriction to Africa, Madagascar, Australia, and temperate to tropical parts of Europe and Asia. It provides evidence of further ecological diversity in early stem Coracii and convergence on crown morphologies. The new species contributes to mounting evidence that extant distributions for major avian subclades may be of comparatively recent origin. Further late Palaeogene sampling is needed to elucidate potential drivers for shifting avian distributions and disappearance of Coracii from North America. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 157 , 586–611.  相似文献   

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The cranial osteology of the small theropod dinosaur Proceratosaurus from the Bathonian of Minchinhampton, England, is described in detail, based on new preparation and computed tomography (CT) scan images of the type, and only known, specimen. Proceratosaurus is an unusual theropod with markedly enlarged external nares and a cranial crest starting at the premaxillary–nasal junction. The skull is highly pneumatic, with pneumatized nasals, jugals, and maxillae, as well as a highly pneumatic braincase, featuring basisphenoid, anterior tympanic, basipterygoid, and carotid recesses. The dentition is unusual, with small premaxillary teeth and much larger lateral teeth, with a pronounced size difference of the serrations between the mesial and distal carina. The first dentary tooth is somewhat procumbent and flexed anteriorly. Phylogenetic analysis places Proceratosaurus in the Tyrannosauroidea, in a monophyletic clade Proceratosauridae, together with the Oxfordian Chinese taxon Guanlong. The Bathonian age of Proceratosaurus extends the origin of all clades of basal coelurosaurs back into the Middle Jurassic, and provides evidence for an early, Laurasia‐wide, dispersal of the Tyrannosauroidea during the late Middle to Late Jurassic. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009.  相似文献   

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Cotyledon areoles, a seed character unique to papilionoid legumes, are reported for the first time in the legume tribe Swartzieae, an anomalous group sometimes considered to be intermediate between subfamilies Caesalpinioideae and Papilionoideae. Bobgunnia madagascariensis has a linear, slightly branched cotyledon areole on the abaxial surface of each cotyledon. Previous reports of other papilionoid seed features in this species are confirmed and extended. These highly distinctive papilionoid seed structures, and recent reports from floral ontogeny and molecular systematics which show Bobgunnia to be closely related to Swartzia and several other genera of Swartzieae, add further evidence to assertions that Swartzia seed structures are derived by simplification from a papilionoid seed, and not by retention of less specialized caesalpinioid seed features. The function and evolutionary advantage of cotyledon areoles are unknown and need investigation. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 287–291.  相似文献   

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The family Galatheidae is among the most diverse families of anomuran decapod crustaceans, and the South‐West Pacific is a biodiversity hot spot for these squat lobsters. Attempts to clarify the taxonomic and evolutionary relationships of the Galatheidae on the basis of morphological and molecular data have revealed the existence of several cryptic species, differentiated only by subtle morphological characters. Despite these efforts, however, relationships among genera are poorly understood, and the family is in need of a detailed systematic review. In this study, we assess material collected in different surveys conducted in the Solomon Islands, as well as comparative material from the Fiji Islands, by examining both the morphology of the specimens and two mitochondrial markers (cytochrome oxidase subunit I, COI, and 16S rRNA). These two sources of data revealed the existence of eight new species of squat lobster, four of which were ascribed to the genus Munida, two to the genus Paramunida, one to the genus Plesionida, and the last species was ascribed to the genus Agononida. These eight species are described along with phylogenetic relationships at the genus level. Our findings support the taxonomic status of the new species, yet the phylogenetic relationships are not yet fully resolved. Further molecular analysis of a larger data set of species, and more conserved genes, will help clarify the systematics of this group. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 465–493.  相似文献   

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Rice rats (Sigmodontinae: Oryzomyini) are abundant in the Late Quaternary fossil record and in Holocene pre‐Columbian archaeological middens across the Lesser Antilles. All of these rice rats are now extinct, and their regional diversity and systematics remain extremely poorly understood. We redescribe all of the region's rice rat taxa known from adequate diagnostic material (Megalomys desmarestii, Megalomys luciae, and Oligoryzomys victus), and describe a new genus and species, Pennatomys nivalis gen. et sp. nov. , from archaeological sites on St. Eustatius, St. Kitts, and Nevis, which formed a single larger island during Quaternary low sea‐level stands. Cladistic analysis supports the inclusion of O. victus within Oligoryzomys, and identifies Megalomys as a sister group of the large‐bodied genera Sigmodontomys or Sigmodontomys + Nectomys, suggesting that large body size in Megalomys represents phyletic gigantism rather than ‘island gigantism’. Megalomys and Pennatomys belong to an oryzomyine clade that has undergone remarkable radiation throughout the oceanic and continental‐shelf islands of the Neotropical region, but these genera do not represent a monophyletic group within the Nectomys subclade, indicating multiple over‐water colonization events of the Lesser Antillean island chain. Although Lesser Antillean rice rats were heavily exploited by prehistoric Amerindians, it is likely that most or all of these taxa survived until European arrival in the region. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 748–772.  相似文献   

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Ornithischia is a morphologically and taxonomically diverse clade of dinosaurs that originated during the Late Triassic and were the dominant large‐bodied herbivores in many Cretaceous ecosystems. The early evolution of ornithischian dinosaurs is poorly understood, as a result in part of a paucity of fossil specimens, particularly during the Triassic. The most complete Triassic ornithischian dinosaur yet discovered is Eocursor parvus from the lower Elliot Formation (Late Triassic: Norian–Rhaetian) of Free State, South Africa, represented by a partial skull and relatively complete postcranial skeleton. Here, the anatomy of Eocursor is described in detail for the first time, and detailed comparisons are provided to other basal ornithischian taxa. Eocursor is a small‐bodied taxon (approximately 1 m in length) that possesses a plesiomorphic dentition consisting of unworn leaf‐shaped crowns, a proportionally large manus with similarities to heterodontosaurids, a pelvis that contains an intriguing mix of plesiomorphic and derived character states, and elongate distal hindlimbs suggesting well‐developed cursorial ability. The ontogenetic status of the holotype material is uncertain. Eocursor may represent the sister taxon to Genasauria, the clade that includes most of ornithischian diversity, although this phylogenetic position is partially dependent upon the uncertain phylogenetic position of the enigmatic and controversial clade Heterodontosauridae. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 648–684.  相似文献   

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During a stay at the Kirstenbosch Research Centre in Cape Town (South Africa), several groups of Asteraceae were studied. One of these was the genus Marasmodes (tribe Anthemideae). After a careful taxonomic study of additional material, including the first species described by A. P. de Candolle, the author has concluded that eight collections should be considered as new species. These new species are described and their relationships with the most similar species of the genus are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 330–342.  相似文献   

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The diversification and early evolution of neosauropod dinosaurs is mainly recorded from the Upper Jurassic of North America, Europe, and Africa. Our understanding of this evolutionary stage is far from complete, especially in the Southern Hemisphere. A partial skeleton of a large sauropod from the Upper Jurassic Cañadón Calcáreo Formation of Patagonia was originally described as a ‘cetiosaurid’ under the name Tehuelchesaurus benitezii. The specimen is here redescribed in detail and the evidence presented indicates that this taxon is indeed a neosauropod, thus representing one of the oldest records of this clade in South America. A complete preparation of the type specimen and detailed analysis of its osteology revealed a great number of features of phylogenetic significance, such as fully opisthocoelous dorsal vertebrae, the persistence of true pleurocoels up to the first sacral vertebra, associated with large camerae in the centrum and supraneural camerae, and an elaborate neural arch lamination, including two apomorphic laminae in the infradiapophyseal fossa. The phylogenetic relationships of this taxon are tested through an extensive cladistic analysis that recovers Tehuelchesaurus as a non‐titanosauriform camarasauromorph, deeply nested within Neosauropoda. Camarasauromorph sauropods were widely distributed in the Late Jurassic, indicating a rapid evolution and diversification of the group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 605–662.  相似文献   

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Fossils reported previously from the Early Silurian (Llandovery) lower Massanutten Sandstone (Virginia, USA) are formally described here as Prattella massanuttense gen. & sp. nov. Organization into cellular filaments embedded in extracellular matrix, the sizes of cells and filaments and the fluvial origin of deposits that host the fossils are all consistent with cyanobacterial affinity. Prattella massanuttense combines preservation as carbonaceous compression at a macroscopic scale with cellular preservation by mineral replacement of cell contents at a microscopic scale. These fossils provide the earliest direct evidence for the occurrence of cyanobacteria in fluvial habitats and add to the knowledge of terrestrial ecosystems that hosted early stages of land plant evolution. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 284–289.  相似文献   

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