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The Traversodontidae is a Triassic family of nonmammalian cynodonts, recorded worldwide, characterized by its bucco-lingually expanded postcanines. A recently discovered fauna in the locality of Santa Cruz do Sul, corresponding to the Santa Maria Formation of the Brazilian Middle/Upper Triassic (Ladinian/Carnian), is made up exclusively of nonmammalian cynodonts with an abundance of traversodontids. A new taxon, Santacruzodon hopsoni gen. et sp. nov . , the most commonly recorded traversodontid cynodont in the fauna, is described here. It is diagnosed by an autapomorphy, a very large posterolabial cusp in the upper postcanine, representing more than half of the labial crest, and a suite of traits present in other traversodontids. Among these features are the descendent flange of the jugal developed as a ball-shaped projection, also known in the Madagascan traversodontid Dadadon isaloi , and the presence of symmetrical incisors with numerous mesial and distal marginal cuspules, feature shared with the North American taxon Arctotraversodon plemmyridon . A phylogenetic analysis of traversodontids from Gondwana, based on a data matrix of 28 characters (mostly dental) and 15 terminals (13 traversodontids, including the new species, plus Diademodon and Trirachodon ) was performed. The new traversodontid appears as the sister taxon of Dadadon . A monophyletic Carnian group composed of Exaeretodon , Menadon and Scalenodontoides , with the Carnian Gomphodontosuchus , and the Ladinian Massetognathus as successive outgroups is also supported. In line with a recent phylogenetic hypothesis, a nonmonophyletic relationship for Scalenodon 'species' from the Anisian Manda beds also results from our analysis. Based on the cladogram obtained, morphological trends of change in the dentition of traversodontids throughout the Triassic are suggested.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 139 , 529−545.  相似文献   

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A new species of Cephalocarida belonging to the genus Lightiella is described. Like all known species of Lightiella , the new species is characterized by reduction of trunk segment 8, which also lacks both pleura and thoracopods. The diagnostic characters of the species are: (1) one seta on the inner distal corner of the penultimate endopodal segment of second maxilla and thoracopods 1–5; (2) only one claw on the distal segment of the endopod of thoracopod 6. A cladistic analysis of 27 morphological characters was used to estimate the phylogeny of all species of Lightiella , with all other cephalocarid species used as outgroups. The discovery of this species in the Mediterranean fills a gap in the distribution of the genus and of the entire class.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 209–220.  相似文献   

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Recent revision of North African specimens of Isoetes velata A. Braun and the closely related taxon I. longissimum Bory, together with Spanish material conventionally designated I. longissimum , suggests that the Spanish specimens constitute a new species, I. fluitans . This is described and illustrated. The North African taxon I. longissimum is probably not specifically distinct from I. velata .  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 231–236.  相似文献   

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A new species of fossil Tubulidentata has been found by the Mission Paléoanthropologique Franco-Tchadienne in Northern Chad. It is the first fossil Orycteropodidae (aardvark) from the Mio-Pliocene of Central Africa. The new taxon, Orycteropus abundulafus sp. nov. , is considered in the framework of the available Orycteropodidae fossil record. The Chadian specimen is characterized by the highest dental robustness index among all Tubulidentata, the presence of crests on the pterygoid, the triangular-shaped olecranon fossa and the reduction of the deltoid crest. All of these characters are linked to a less fossorial animal that had a tougher diet. This new African species is closer to the Eurasian O. gaudryi than to any other Tubulidentata. Together they form a clade distinct from that which includes O. afer . This is the first evidence of a relationship for aardvarks between Africa and Eurasia. An initial step is made towards revision of the phylogeny of the order.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 109–131.  相似文献   

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The evolutionary relationships of the Recent Pterioidea are inferred from a phylogenetic analysis of representatives of all pterioidean genera based on original observations of anatomy and shell morphology, and an extensive survey of bivalve literature. The well-resolved cladogram supports monophyly for the superfamily, but renders all but one family (the monotypic Pulvinitidae) polyphyletic. In addition, these results reveal a considerable level of convergence and parallelisms through the Pterioidea. The branching order of pterioid genera in the morphological analysis is largely corroborated by the sequence of their appearance in the fossil record. The palaeontological evidence provides important information on dating lineage splitting events and transitional taxa. The proposed phylogeny integrates the cladistic analysis of the Recent Pterioidea with the fossil record and suggests that the crown-group pterioideans probably originated in the Triassic from the Bakevelliidae, an extinct paraphyletic stem group from which the Ostreoidea are also ultimately derived.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 253–312.  相似文献   

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The tetrapod faunas from the terrestrial Middle–Late Triassic basins of Africa and South America are among the richest in the world, especially in non‐mammalian cynodonts. Despite the great abundance of cynodont specimens found in these basins, there are few known taxa that exhibit interbasinal distributions. Here we describe a new species of traversodontid cynodont of the genus Scalenodon from the Triassic Dinodontosaurus Assemblage Zone of the Santa Maria Supersequence, from the state of Rio Grande do Sul, Brazil. Scalenodon ribeiroae sp. nov. is based on a partial skull that possesses a combination of features not observed in any other South American traversodontid: ellipsoid upper postcanines with the transverse crest formed by three cusps, lacking a mesiobuccal accessory cusp, and with lingual cusp projected lingually creating a concave lingual surface on the upper postcanines; the paracanine fossa is positioned medially to the upper canine, and jugal lacks a suborbital process. A phylogenetic analysis places the new taxon in a basal position within the Family Traversodontidae, with the African Scalenodon angustifrons as sister‐taxon. The new specimen of Scalenodon represents the first record of this genus outside of the Manda Beds of Tanzania, and reinforces the biostratigraphical and biogeographical connection between Gondwanan Middle–Late Triassic tetrapod faunas. Although recent advances have been made, our current knowledge of these faunas is limited by the lack of absolute dates for most units and by uncertainties in the taxonomy and stratigraphical provenance of key fossils.  相似文献   

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Five new species of land snail (family Enidae) are described from La Gomera (Canary Islands) of which the majority, on the basis of anatomy alone, could be incorporated within a new supraspecific taxon. In addition to the morphological study of these new species, a region of the 16S mitochondrial gene is sequenced from three of the new species and a range of species of Napaeus from within its two subgenera ( Napaeinus and Napaeus ) . There is a disparity between the morphological and preliminary molecular phylogenetic data. Possible explanations for this conflict are discussed, as well as the evolutionary relationships among these different taxa, and it is suggested that this group may be an excellent model for further studies of adaptation and diversification.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 169–187.  相似文献   

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A new species, Bellium artrutxensis (Asteraceae: Astereae), is described from the therophytic pastures of southern Minorca (Balearic Islands). The analysis of nuclear ribosomal internal transcribed spacer (ITS) sequences showed that the new taxon was closely related to Bellium bellidioides , but differed with regard to the annual lifespan, the absence of epigeal stolons, and the presence of a patent eglandular indumentum on the leaves. The new taxon shows morphological features that are well suited for the colonization of dry environments with a marked summer drought, and may be of adaptive significance. The new species is diploid (2 n  = 18) and shows up to two accessory chromosomes in root tissues. B chromosomes have not been reported previously in other species of Bellium .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 65–77.  相似文献   

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Nigella turcica a new species endemic to north-eastern Turkey is described and illustrated. Morphological differences between the species and the closely related species, N. sativa , are discussed and the IUCN threatened category is proposed. A distribution map of the new species and its related taxon is given.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 251–255.  相似文献   

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Arctotis debensis R.J.McKenzie, a new species from the Albany Centre of Floristic Endemism, South Africa, is described and illustrated. It grows almost exclusively in grassland on kommetjies, a distinctive landform of depressions and mounds associated with giant earthworms, in a restricted area west of King William's Town, Eastern Cape Province. It is the first plant taxon reported to be endemic or near-endemic to this unusual habitat. The new species appears to have been collected rarely and previous collections examined have remained undetermined to species level. The new species is distinguished from closely allied species by the combination of its usually larger dimensions in all parts, prostrate habit, coriaceous leaves that are green, scabrous, and eglandular on the adaxial surface and densely lanate on the abaxial surface, and involucral-bract morphology.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 581–588.  相似文献   

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The evolutionary history of bioluminescence and iridescence in myodocopid ostracods was estimated by phylogenetic analysis of mitochondrial 16S ribosomal RNA sequences. The inferred phylogeny of the myodocopids suggests that the common ancestor of Myodocopida evaluated in this study exhibits iridescence. This type of light emission was once lost and recaptured independently in the descendant lineages. Bioluminescent species also evolved from non-luminous ancestral species. In the suborder Myodocopina, all the bioluminescent species form a monophyletic group, suggesting that bioluminescence evolved only once. Structural differences between two bioluminescent groups in the order Myodocopida suggests independent origins for bioluminescence.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 449–455.  相似文献   

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Noccaea camlikensis sp. nov. (Brassicaceae) is described and illustrated from a localized serpentine range in southern Turkey. Its close relationship to N. cariensis , from which it differs in leaf and carpological characters, is discussed. The protologue of this fairly unknown species can now be amended to cover better the morphological variability of this taxon. A comparative study of seed-coat anatomy advocates its move from Thlaspi to Noccaea ; the relevant combination N. cariensis (Carlström) Parolly, Nordt & Aytaç is made. The ecology of both vicarious species is discussed and their distribution mapped.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 409–416.  相似文献   

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The desert plated lizard ( Angolosaurus skoogi ), a 'sand sea' endemic of the northern Namib Desert, exhibits remarkable morphological convergence with other dune-dwelling lizards worldwide. This distinct ecomorphic condition sets Angolosaurus apart from the remaining genera in the family Gerrhosauridae. Indeed, a morphological phylogeny addressing generic relationships within the Cordyliformes (Cordylidae + Gerrhosauridae) identified Angolosaurus as the earliest diverging taxon among African gerrhosaurids. We re-evaluated the basal status of Angolosaurus , conducting a molecular phylogenetic analysis of the African and Madagascan gerrhosaurid genera. Our survey involved a comprehensive species-level comparison among the four nominal genera of mainland Africa ( Angolosaurus , Cordylosaurus , Tetradactylus and Gerrhosaurus ). Mitochondrial DNA sequence data from the cytochrome b , ND2, 12S and 16S rRNA genes were combined for analysis using both parsimony and maximum likelihood procedures. In contrast to the morphological hypothesis, our results do not depict Angolosaurus as the sister taxon to other African gerrhosaurids. Rather, the molecular analyses consistently place Angolosaurus within Gerrhosaurus , rendering the latter genus paraphyletic.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78 , 253–261.  相似文献   

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A new species, Linum vuralianum Yılmaz & Kaynak, is described and illustrated from west Anatolia, Turkey. It is closest to L. flavum L., but differs by its annual or biennial life form, the presence of rosette leaves at anthesis, and the absence of staminodes. The World Conservation Union (IUCN) threat category and observations on the population are noted. The geographical distribution of the new species and its related taxon is given.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 459–462.  相似文献   

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Species-level phylogeny of the Butterfly tribe Argynnini is established based on 141 characters derived from wing and genitalia morphology of both sexes. The Argynnini can be divided into three subtribes; Yrameina comprising Yramea and Boloria s . l ., Argynnina comprising Prokuekenthaliella , Issoria , Brenthis , and all the 'large fritillary' species joined in the genus Argynnis s . l . and a new subtribe Euptoietina comprising only the genus Euptoieta . The classical genus Issoria s . l . is polyphyletic regarding Yramea and possibly paraphyletic regarding the two Afrotropic species baumanni and hanningtoni ; these two species are tentatively transferred to the old genus/subgenus Prokuekenthaliella . Surprisingly, one Afrotropic species, Issoria smaragdifera is closely related to the East Palaearctic Issoria species. A revised classification of Argynnini is proposed based on the obtained phylogeny. Studies of larval host plants based on the obtained phylogeny suggest that the ancestral Argynnini used Passiflora and Violaceae, but already the ancestor of Yrameina + Argynnina was probably specialized on Violaceae. Whereas the Boloria species have turned to other food plants such as Dryas , Vaccinium and Salix on several occasions, only Brenthis among the Argynnina use other host plants than Viola (mainly Rosaceae). The habit of laying eggs away from the food plant has probably evolved twice within Argynnina.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 627–673.  相似文献   

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