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1.
The Anopheles genus is a member of the Culicidae family and consists of approximately 460 recognized species. The genus is composed of 7 subgenera with diverse geographical distributions. Despite its huge medical importance, a consensus has not been reached on the phylogenetic relationships among Anopheles subgenera. We assembled a comprehensive dataset comprising the COI, COII and 5.8S rRNA genes and used maximum likelihood and Bayesian inference to estimate the phylogeny and divergence times of six out of the seven Anopheles subgenera. Our analysis reveals a monophyletic group composed of the three exclusively Neotropical subgenera, Stethomyia, Kerteszia and Nyssorhynchus, which began to diversify in the Late Cretaceous, at approximately 90 Ma. The inferred age of the last common ancestor of the Anopheles genus was ca. 110 Ma. The monophyly of all Anopheles subgenera was supported, although we failed to recover a significant level of statistical support for the monophyly of the Anopheles genus. The ages of the last common ancestors of the Neotropical clade and the Anopheles and Cellia subgenera were inferred to be at the Late Cretaceous (ca. 90 Ma). Our analysis failed to statistically support the monophyly of the Anopheles genus because of an unresolved polytomy between Bironella and A. squamifemur.  相似文献   

2.
Mosasauroids are conventionally conceived of as gigantic, obligatorily aquatic marine lizards (1000s of specimens from marine deposited rocks) with a cosmopolitan distribution in the Late Cretaceous (90–65 million years ago [mya]) oceans and seas of the world. Here we report on the fossilized remains of numerous individuals (small juveniles to large adults) of a new taxon, Pannoniasaurus inexpectatus gen. et sp. nov. from the Csehbánya Formation, Hungary (Santonian, Upper Cretaceous, 85.3–83.5 mya) that represent the first known mosasauroid that lived in freshwater environments. Previous to this find, only one specimen of a marine mosasauroid, cf. Plioplatecarpus sp., is known from non-marine rocks in Western Canada. Pannoniasaurus inexpectatus gen. et sp. nov. uniquely possesses a plesiomorphic pelvic anatomy, a non-mosasauroid but pontosaur-like tail osteology, possibly limbs like a terrestrial lizard, and a flattened, crocodile-like skull. Cladistic analysis reconstructs P. inexpectatus in a new clade of mosasauroids: (Pannoniasaurus (Tethysaurus (Yaguarasaurus, Russellosaurus))). P. inexpectatus is part of a mixed terrestrial and freshwater faunal assemblage that includes fishes, amphibians turtles, terrestrial lizards, crocodiles, pterosaurs, dinosaurs and birds.  相似文献   

3.
Abstract: During the last two decades, a range of microfossils have been collected from strata of Late Cretaceous (Coniacian–Maastrichtian) age. The name gilianelles has been coined to accommodate these microproblematica. On the basis of many thousands of specimens, typical features of this group have now been assessed. Distinctive traits are calcareous unilocular, basically axially symmetrical test, in the size range 80–200 μm, with a single‐layered wall of radially arranged crystals, 15 μm thick, the outer surface with a crochet‐like nanostructure, a small‐sized aperture (one tenth of test diameter), situated on the upper surface in vivo. Secondary criteria include modification of axial test symmetry into radial or bilateral symmetry, development of expansions, either spiny or laminar and presence of longitudinal and latitudinal ornament. To date, 60 taxa have been described from northern Spain to northern Germany and from Central America. Evolutionary patterns of gilianelles are diverse, with both short‐ and long‐ranging forms, some of which comprise lineages that were affected by a marked crisis dated at about 73 Ma. This event is here illustrated by the tribe Coraliellini, of which a key taxon, Coraliella cognatio, is described as new. Previous interpretations of Gilianelles as dinoflagellate cysts are discussed and rejected.  相似文献   

4.
The first record of an undoubted opossum-like marsupial from the Mesozoic of Europe indicates an invasion from North America at the end of Late Cretaceous (Maastrichtian). The new 66.1 million-year-old marsupial, Maastrichtidelphys meurismeti n. gen., n. sp., represented by a right upper molar, comes from the type Maastrichtian of The Netherlands. The Maastricht marsupial exhibits affinities with earlier (early Maastrichtian) North American herpetotheriids providing definitive evidence of a high-latitude North Atlantic dispersal route between North America and Europe during the latest Cretaceous. Previously, the first major interchange for marsupials was thought to have occurred nearly 10 million years later in the Eocene. The occurrence of this new marsupial in Europe implies that at some time during the latest Cretaceous, sea level and climatic conditions must have been sufficiently favorable to allow for such a high-latitude dispersal. The fragmentary remains of hadrosaurid and theropod dinosaurs, as well as boid snakes from northwestern Europe which have affinities with North American taxa help substantiate assumptions made by the occurrence of the herpetotheriid marsupial in Maastricht.  相似文献   

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A series of cranial remains as well as a few postcranial elements attributed to the basal eusuchian Allodaposuchus precedens are described from Velaux‐La Bastide Neuve, a Late Cretaceous continental locality in southern France. Four skulls of different size represent an ontogenetic series and permit an evaluation of the morphological variability in this species. On this basis, recent proposals that different species of Allodaposuchus inhabited the European archipelago are questioned and A. precedens is recognized from other Late Cretaceous deposits of France and Romania. A dentary bone is described for the first time in A. precedens and provides a basis to reconsider the validity of two taxa, Ischyrochampsa meridionalis and Musturzabalsuchus buffetauti, which are interpreted as possible junior synonyms of Allodaposuchus. These results allow the diversity of Late Cretaceous eusuchians from Europe to be refined and recognize a basal stock known as the Hylaeochampsidae sharing an absence of external mandibular fenestrae. Within this family, Allodaposuchus occupies a basal position relative to Acynodon, Iharkutosuchus and Hylaeochampsa. © 2015 The Linnean Society of London  相似文献   

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Derived large-mouthed snakes (macrostomatans) possess numerous specializations in their skull and lower jaws that allow them to consume large vertebrate prey. In contrast, basal snakes lack these adaptations and feed primarily on small prey items. The sequence of osteological and behavioral modifications involved in the evolution of the macrostomatan condition has remained an open question because of disagreement about the origin and interrelationships of snakes, the paucity of well-preserved early snake fossils on many continental landmasses, and the lack of information about the feeding ecology of early snakes. We report on a partial skeleton of a new 3.5-m-long snake, Sanajeh indicus gen. et sp. nov., recovered from Upper Cretaceous rocks of western India. S. indicus was fossilized in association with a sauropod dinosaur egg clutch, coiled around an egg and adjacent to the remains of a ca. 0.5-m-long hatchling. Multiple snake-egg associations at the site strongly suggest that S. indicus frequented nesting grounds and preyed on hatchling sauropods. We interpret this pattern as “ethofossil” preservation of feeding behavior. S. indicus lacks specializations of modern egg-eaters and of macrostomatans, and skull and vertebral synapomorphies place it in an intermediate position in snake phylogeny. Sanajeh and its large-bodied madtsoiid sister taxa Yurlunggur camfieldensis and Wonambi naracoortensis from the Neogene of Australia show specializations for intraoral prey transport but lack the adaptations for wide gape that characterize living macrostomatan snakes. The Dholi Dungri fossils are the second definitive association between sauropod eggs and embryonic or hatchling remains. New fossils from western India provide direct evidence of feeding ecology in a Mesozoic snake and demonstrate predation risks for hatchling sauropod dinosaurs. Our results suggest that large body size and jaw mobility afforded some non-macrostomatan snakes a greater diversity of prey items than previously suspected on the basis of extant basal snakes.  相似文献   

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In 1905, Nopcsa tentatively identified a fragmentary rib from the Jibou Formation at Someş Odorhei as belonging to an ornithopod dinosaur. Therefore, he concluded that the base of this formation is Late Cretaceous, but this hypothesis was subsequently ignored or rejected by other authors. New dinosaur bones discovered in this locality by new excavations are here interpreted as belonging to the euornithopod Zalmoxes shqiperorum Weishampel, Jianu, Csiki and Norman, 2003. The base of the Jibou Formation can therefore be regarded as Maastrichtian, correlative to the Sânpetru Formation and to the middle member of the Densuş Ciula Formation from the Haţeg Basin, as well as the base of the Şard Formation in the southwestern Basin of Transylvania, in the Alba Iulia area. The presence of Zalmoxes at Someş Odorhei also confirms the northeastern extension for the ‘Haţeg Island’ in Transylvania.  相似文献   

11.
Two recently collected specimens of the Late Cretaceous pterosaurNyctosaurus differ from all previously known specimens in the possession of a large branching cranial crest. The crest extends upward and backward from the posterior skull roof and is nearly three times the length of the skull proper. Despite the large crest, the specimens do not differ significantly in morphology from previously known specimens ofNyctosaurus, and do not seem to represent a new species ofNyctosaurus. The specimens suggest that the cranial crest was developed late in ontogeny, which is consistent with the interpretation of pterosaur cranial crests as intraspecific display structures.   相似文献   

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A solution to higher level mammalian phylogeny is going to depend on the congruent establishment of superordinal groupings followed by a linking together of these clades. We present congruent and convincing evidence from four disparate nuclear protein coding genes and from a tandem alignment of the 12S–16S mitochondrial region, for a superordinal clade of endemic African mammals that includes elephant shrews, aardvarks, golden mole, elephants, sirenians, and hyraxes. Because of strong support for golden mole as part of this clade, the Insectivora are rendered paraphyletic or polyphyletic, with constrained monophyly of the insectivores judged significantly worse in the vast majority of tests. Branching arrangement within this clade remains highly uncertain; however, a tandem alignment of the protein coding genes suggests elephant shrew is the earliest African lineage. None of the individual data sets or combinations of data sets support the widely held view of a mirorder Tethytheria (Sirenia/Proboscidea), although only a tandem alignment of protein coding and mitochondrial loci significantly rejects this association. The majority of the data sets and analyses provide strong support for Caviomorpha as part of a monophyletic Rodentia.  相似文献   

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Although the Bothremydidae are the most abundant and diverse group of turtles in the Upper Cretaceous fauna of Europe, the record attributed to the genus Elochelys was, until now, quite scarce. However, the revision of the specimens previously attributed to this taxon and the analysis of new material from the Spanish record significantly increase our knowledge of these turtles. Evaluation of the morphological variability, affecting many characters that have been considered diagnostic until now and comparisons with other members of the node Bothremydini, allow us to amend the diagnosis of the genus Elochelys, recognising Elochelys perfecta as a valid single species and reassigning its other representative, “Elochelys” convenarum, to the new genus Iberoccitanemys.  相似文献   

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A new notosuchian crocodyliform from the Late Cretaceous Bauru Group found in the southeastern State of São Paulo (Brazil) is described here. The new taxon, Caipirasuchus stenognathus, is referred as a new species of the recently erected genus Caipirasuchus within the clade Sphagesauridae based on a phylogenetic analysis of basal mesoeucrocodylians. Caipirasuchus stenognathus is represented by an almost complete skull and lower jaw that has autapomorphic characters that distinguish it from other species of Sphagesauridae. These autapomorphies include: maxilla forming part of the orbital margin (absence of lacrimal-jugal contact), nasal with smooth depressions on the posterior region close to the contact with the maxilla and lacrimal, postorbital with posterior palpebral facet that extends posteriorly underneath the ear-flap groove, and a distinct anterior process of the medial flange of the retroarticular process. Additionally, the new taxon lacks autapomorphic features described in other sphagesaurids. The phylogenetic analysis results in a monophyletic genus Caipirasuchus, that is the sister group of a clade fomed by Sphagesaurus huenei, Caryonosuchus pricei, and Armadillosuchus arrudai. Sphagesaurids also include a basal clade formed by Adamantinasuchus navae and Yacarerani boliviensis. Other notosuchian taxa, such as Mariliasuchus amarali, Labidiosuchus amicum, Notosuchus terrestris, and Morrinhosuchus luziae are successive sister taxa of Sphagesauridae, forming a clade of advanced notosuchians that are restricted to the Late Cretaceous of South America. These results contrast with most previous phylogenetic hypotheses of the group that depicted some members of Sphagesauridae as more closely related to baurusuchids, or found Asian (e.g., Chimaerasuchus) or African (Malawisuchus, Pakasuchus) forms nested within advanced notosuchians that are, according to our analysis, endemic of the Late Cretaceous of South America.  相似文献   

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Two taxa of cupulate magnoliid fossil flowers, Cronquistiflora and Detrusandra, are described from the Late Cretaceous (Turonian, ∼90 million years before present [MYBP]) Raritan (or lower Magothy) Formation of New Jersey. The fossil taxa are represented by flowers at various stages of development, associated fragments of cup-shaped floral receptacles with attached anthers, and isolated anthers. Both taxa have laminar stamens with adaxial thecae and valvate dehiscence. Pollen is boat-shaped and foveolate in anthers associated with Cronquistiflora and spherical with reticulate ornamentation in Detrusandra. Cup-shaped receptacles are externally bracteose in both taxa. The receptacle of Cronquistiflora is broader than the campanulate one of Detrusandra. Cronquistiflora also has more carpels (∼50 in a spiral vs. ∼5 in a whorl or tight spiral). In Detrusandra the carpels are surrounded by dorsiventrally flattened structures (pistillodes?) that are remote from the attachment of the stamens near the distal rim of the receptacular cupule. Detrusandra stigmas are rounded and bilobed, while those of Cronquistiflora, although bilateral in symmetry, are somewhat peltate. The fossil taxa share prominent characters with extant cupulate magnoliids (e.g., Eupomatia, Calycanthus), but also share characters with other magnoliids including Winteraceae. These fossils represent taxa that are character mosaics relative to currently recognized families. Inclusion of these fossils in existing data matrices and ensuing phylogenetic analyses effect changes in tree topologies consistent with their mosaicism relative to modern taxa. But such analyses do not definitively demonstrate the affinities of the fossils other than illustrating that these fossils are generalized magnoliids. Additional analysis of modern and fossil magnoliids is necessary to fully appreciate the phylogenetic significance and positions of these fossil taxa. However, the results of the phylogenetic analyses do introduce the possibility that extinct taxa of Magnoliales with cupulate floral receptacles were transitional between basal angiosperms and those with tricolpate pollen. The fossils provide insights into the timing of evolution of character complexes now associated with coleopteran pollination.  相似文献   

20.
Recent discoveries in southern France and northern Spain suggest that the morphology of titanosaurian teeth shows much greater variations that previously thought. It is suggested that the different morphotypes are informative at specific or generic level and that titanosaurian genera may indeed be recognized by their isolated teeth. It is also confirmed that juvenile titanosaurian teeth have a rather uniform, cylindrical morphology. Four different morphotypes are described for the Ibero-Armorican Island in the Late Cretaceous.  相似文献   

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