Biodiversity and Sequence of the Middle Triassic Panxian Marine Reptile Fauna,Guizhou Province,China

The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.

A New Ceratopsian from the Upper Jurassic Houcheng Formation of Hebei, China

A new ceratopsian taxon Xuanhuaceratops niei gen. et sp. nov. is erected based on four fragmentary specimens collected from the Late Jurassic Houcheng Formation, Hebei Province, China. Xuanhuaceratops shares a number of derived features with, and is closely related to, another probable Late Juarassic ceratopsian Chaoyangsaurus youngi, from which it differs in only possessing a single premaxlllary tooth as well as in details of quadrate and scapular morphology. We hypothesize that these two taxa represent a primitive lineage of Ceratopsia that is basal to the psittacosauridneoceratopsian diversity, and propose the name Chaoyangsauridae for it.

Biogeographic diversification in Nolana(Solanaceae),a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.

Phylogeny and putative hybridization in the subtribe Paranepheliinae （Liabeae, Asteraceae）, implications for classification, biogeography, and Andean orogeny

The nuclear ribosomal ITS region and the chloroplast trnL-trnF (trnLF) intergenic region were se-quenced for 45 accessions of Paranephelius and six accessions of Pseudonoseris, the two genera of the subtribe Paranepheliinae (Liabeae, Asteraceae) distributed in the alpine regions of the Andes. This data set was used to estimate relationships between these genera and within each genus to aid in evaluating morphological variation and classification. Our results with both ITS and trnLF markers support the monophyly of subtribe Paranephelii-nae, and place Pseudonoseris discolor as the first diverged taxon sister to the clade containing Paranephelius. Pseudonoseris szyszylowiczii exhibited intraspecific divergence supporting intergeneric hybridization between Pseudonoseris and Paranephelius. Within Paranephelius, genetic divergence is low and not adequate to fully resolve phylogenetic relationships at the species level, but two genetically and morphologically recognizable groups were revealed by the ITS data. Several accessions possessing multiple ITS sequences represent putative hybrids between the two groups. These putative hybrids have caused some taxonomic confusion and difficulties in establishing species boundaries in Paranephelius. The divergence time estimates based on ITS sequences indi-cated that the stem of subtribe Paranepheliinae dates to 13 million years ago, but the diversification of the crown clade of the extant members began in the early Pleistocene or late Pliocene, perhaps associated with the uplift of the Andes and the climatic changes of global cooling.

山东日照两城镇龙山文化(4600～4000aB·P.)遗址出土木材的古气候意义

通过分析考古遗址中出土木材样品的树种,能够获得龙山文化前时期区域气候与植被环境的信息。文章采用体视显微镜和扫描电子显微镜,对山东日照两城镇遗址出土的部分木材样品进行树种鉴定。分析与研究的结果表明:龙山文化前期,两城镇聚落周围生长着麻栎、辽东桤木、杜梨和刚竹等树种,反映了比现在温暖湿润的气候状况,龙山文化的繁荣发展,可能与这种适宜的气候环境有关。研究结果还标志着,在我国东部地区,利用考古遗址中出土的木材等植物遗存,研究全新世时期高分辨率的气候演化过程及其与人类文化的关系,具有广泛的学术前景。

湖南参属的归并及亚洲揔木属(五加科)的一个新种和一些名称的变更(英文)

分子与形态证据表明湖南参 (HunaniopanaxhypoglaucusC .J.Qi&T .R .Cao)起源于木属 (AraliaL .) ,湖南参的近缘种为寄生五叶参 (Araliaparasitica)和轮伞五叶参 (Araliaverticillata) ,形态证据支持湖南参为轮伞五叶参的姐妹种 ,此 2种具轮伞花序这一共衍征。为了保证木属的单系性 ,现将湖南参并入木属 ,并作如下新组合 :Araliahypoglauca (C .J .Qi&T .R .Cao)J.Wen&Y .F .Deng .本文报道了湖南参在广西的新分布。目前的形态学和分子数据均不支持早先提出的湖南参与树参属 (Dendropanax)的近缘关系。本文亦报道了木属的 1新种、 2新种组合和 1个新名称 :AraliashangianaJ .Wen .sp .nov .(向氏五叶参 ,新种 ) ;Araliaglabrifoliolata (C .B .Shang)J .Wen .comb .nov . (光叶五叶参 ,新组合 ) ;Araliastellata (King)J.Wen ,comb .nov . (星毛羽叶参 ,新组合 )和AraliadelavayiJ .Wen .nom .nov .(云南五叶参 ,新名称 )。

Molecular phylogeny of Solms-laubachia(Brassicaceae) s.l.,based on multiple nuclear and plastid DNA sequences,and its biogeographic implications

The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. （Brassicaceae）, have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes （LEAFY and G3pdh） and two chloroplast intergenic spacers （petN-psbM and psbM-trnD） were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum （Maxim.） Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.

Bioactivity‑Guided Isolation of Totarane‑Derived Diterpenes from Podocarpus neriifolius and Structure Revision of 3‑Deoxy‑2α‑hydroxynagilactone E

Bioactivity-guided phytochemical investigation of Podocarpus neriifolius D.Don.(Podocarpaceae)has led to the isolation of one new(2)and three known(1,3,and 4)B-type podolactones,along with three totarane-type diterpenes(5-7).Their structures were determined by interpretation of High Resolution ElectroSpray Ionization Mass Spectrometry(HRESIMS)and 1D and 2D NMR data,and comparison with the values reported in the literature.The structure of compound 1,previously identifed as 3-deoxy-2α-hydroxynagilactone E(8),was revised as its 2β-epimer,which has been reported recently as a new compound.All of the isolates were evaluated for their antiproliferative activity against a panel of four human cancer cell lines,namely,ovarian(OVCAR3),breast(MDA-MB-231),colon(HT-29),and melanoma(MDA-MB-435),and compounds 1 and 3 were found to be cytotoxic with IC_(50) values in the low micromolar range for most of the cell lines used.The major compound,inumakilactone A(3),was further tested in vivo using the HT-29,MDA-MB-435,and OVCAR3 cells in a murine hollow fber model,for the frst time.

Comparison of Serum Phospholipase A₂Activities of All Known Extant Crocodylian Species

Serum samples from all 23 extant crocodilian species were tested for phospholipase A2 (PLA2) activity against nine different bacterial species. The data were used?to generate a PLA2 activity profile for each crocodilian species, and the data were used to compare the activities of the three main lineages (Alligatoridae,?Crocodylidae, and Gavialidae), the seven different genera, and to compare all?of the 23 individual species. The data revealed that the three lineages ofcrocodilians (Alligatoridae, Crocodylidae, and Gavialidae) exhibited PLA2 activities toward nine species of bacteria that were statistically?distinguishable. In?addition,?the PLA2 activities of crocodilians in a specific genus tended to be more similar to other?members in their genus than to members of other crocodilian genera.

A new classification for the family Graphidaceae(Ascomycota:Lecanoromycetes:Ostropales)

A revised classification for the emended family Graphidaceae is proposed,based on recent phylogenetic studies,including the finding that three previously separated families(Asterothyriaceae,Gomphillaceae,Thelotremataceae)are nested within Graphidaceae and in part polyphyletic.The family comprises three major clades which are here delimited as subfamilies Fissurinoideae,Gomphilloideae,and Graphidoideae.The latter is composed of three major clades which are formally delimited as tribes Graphideae,Ocellularieae,and Thelotremateae.In addition,three new genera are described to accommodate the Ocellularia clandestina(Clandestinotrema)group,the Ocellularia cruentata group(Cruentotrema)and Myriotrema pycnoporellum(Pycnotrema).

Phylogenomic analysis of 2556 single-copy protein-coding genes resolves most evolutionary relationships for the major clades in the most diverse group of lichen-forming fungi

Phylogenomic datasets continue to enhance our understanding of evolutionary relationships in many lineages of organisms.However,genome-scale data have not been widely implemented in reconstructing relationships in lichenized fungi.Here we generate a data set comprised of 2556 single-copy protein-coding genes to reconstruct previously unresolved rela-tionships in the most diverse family of lichen-forming fungi,Parmeliaceae.Our sampling included 51 taxa,mainly from the subfamily Parmelioideae,and represented six of the seven previously identified major clades within the family.Our results provided strong support for the monophyly of each of these major clades and most backbone relationships in the topology were recovered with high nodal support based on concatenated dataset and species tree analyses.The alectorioid clade was strongly supported as sister-group to all remaining clades,which were divided into two major sister-groups.In the first major clade the anzioid and usneoid clades formed a strongly supported sister-group relationship with the cetrarioid?hypogymnioid group.The sister-group relationship of Evernia with the cetrarioid clade was also strongly supported,whereas that between the anzioid and usneoid clades needs further investigation.In the second major clade Oropogon and Platismatia were sister to the parmelioid group,while the position of Omphalora was not fully resolved.This study demonstrates the power of genome-scale data sets to resolve long-standing,ambiguous phylogenetic rela-tionships of lichen-forming fungi.Furthermore,the topology inferred in this study will provide a valuable framework for better understanding diversification in the most diverse lineage of lichen-forming fungi,Parmeliaceae.

Molecular phylogeny of the genus Sticta (lichenized Ascomycota: Lobariaceae) in Colombia

We present a molecular phylogenetic study of the lichen genus Sticta focusing on Colombia,using the ITS fungal barcoding gene for a total of 370 ingroup OTUs,with 322 newly generated sequences.The topology resulting from a maximum likelihood approach does not support current species concepts in Sticta,which use a morphological concept,but in contrast shows that similar morphodemes evolved multiple times independently within the genus.As a consequence,currently applied names such as S.fuliginosa and S.weigelii comprise numerous(up to more than 20)unrelated species-level lineages,which can be distinguished also phenotypically using previously unrecognized characters such as lobe configuration,lobe surface structure,tomentum type,and anatomy of the basal membrane of the cyphellae.We conclude that the genus Sticta contains about four to five times the number of species currently recognized.In Colombia alone,approximately 150 species of Sticta are present.

Using a temporal phylogenetic method to harmonize familyand genus-level classification in the largest clade of lichen-forming fungi

Although classification at supra-specific ranks is inherently arbitrary,comparable taxonomic ranks within clades can facilitate more consistent classifications and objective comparisons among taxa.Different circumscriptions of the hyper-diverse lichen-forming fungal family Parmeliaceae and widely different generic circumscriptions among authors have been proposed.For this study,we use a recently developed temporal approach that uses timecalibrated chronograms to identify temporal bands for specific ranks in Parmeliaceae and allied groups with the overarching goal of establishing a consistent,stable classification.A data set of 330 species,representing 73 genera in the family and 52 species of related families was used to address the circumscription of Parmeliaceae and its genera following the proposed temporal approach.Based on the results of this study,we propose a revised,temporal-based classification for Parmeliaceae,including all clades that share a common ancestor 102.13–112.88 Ma for families and a time window of 29.45–32.55 Ma for genera.Fortyfive of the currently accepted genera in Parmeliaceae were supported in their current circumscription.Two subfamilies are accepted within Parmeliaceae:Protoparmelioideae Divakar et al.subfam.nov.,including Protoparmelia and the resurrected genus Maronina,and Parmelioideae,including the bulk of genera in the family.The new genus Austromelanelixia Divakar et al.is proposed to accommodate a clade of southern Hemisphere species previously included in Melanelixia.Eumitria and tentatively Dolichousnea are resurrected as genera separate from Usnea.The following genera are reduced to synonymy:Allocetraria,Cetrariella,Usnocetraria,and Vulpicida with Cetraria;Arctocetraria,Cetreliopsis,Flavocetraria,Kaernefeltia,Masonhalea,Tuckermanella,and Tuckermannopsis with Nephromopsis;and the lichenicolous genera Nesolechia and Raesaenenia with the lichen-forming genera Punctelia and Protousnea,respectively.A total of 47 new combinations and three new names at the species level are proposed.

Phylogenetic placement of lichenicolous Phoma species in the Phaeosphaeriaceae(Pleosporales,Dothideomycetes)

More than twenty species of lichenicolous fungi have been described in Phoma,a large anamorphic genus of primarily plant-associated pathogens with broad geographic distributions.We obtained nuclear and mitochondrial rDNA sequences from 19 fungal cultures isolated from specimens representing four described and two undescribed lichenicolous species in the genus.Our multilocus phylogeny indicates that lichenicolous Phoma species represent at least two phylogenetically distinct clades in the Phaeosphaeriaceae,one including a new species,Phoma puncteliae,isolated from a specimen of Punctelia rudecta collected inMaryland,USA,and another group of primarily lichenicolous species.This latter group includes four described lichenicolous Phoma species,an unidentified melanized rock fungus,and a new lichenicolous Phoma species isolated from Xanthomendoza species collected in Canada that we are naming P.xanthomendozae.Some specimens in this clade collected from different lichen genera and species were found to be very similar genetically,which calls into question the recent practice of recognizing lichenicolous Phoma species mainly by differences in host preference.

Small mammal diversity and habitat requirements in the Kahuzi- Biega National Park and surrounding areas, eastern Democratic Republic of Congo

We conducted a study on diversity and habitat requirements of small mammals in the western part of the AlbertineRift, eastern Democratic Republic of Congo. The work aimed at providing a more complete list of species recordedto date and their habitat requirements to aid conservation efforts in the region. Trapping was conducted usingMuseum special, Victor traps, Sherman live traps and pitfall traps in four different habitats. A total of 57 specieswas recorded. Plantations and open habitats harbored the same species. In the forested areas we recorded 30 specieswhich are not tolerant to disturbance. Eighteen species are Albertine Rift endemics. One species (Lophuromyscinereus), which is vulnerable and data deficient, has been recorded only in swamp. This study has recorded morespecies than the previous studies, some of which have not been reported in earlier studies. Differences between thisand earlier studies are attributed to methods and the areas sampled. Some of the habitats sampled by previousworkers have not been assessed. More research is needed, especially in swamps in mountain areas and in deepforests inhabited by species not present at lower altitudes.

Phylogenomic reconstruction addressing the Peltigeralean backbone(Lecanoromycetes,Ascomycota)

Rapid radiations in Fungi are only beginning to be studied with phylogenomic data.The evolutionary history of the lichenized fungal order Peltigerales has not been well resolved,particularly for the Collematineae.Here,we used concatenation and coalescent-based species tree methods to reconstruct the phylogeny of the Peltigerales based on sequences of 125 nuclear single-copy exon sequences among 60 samples,representing 58 species.Despite uneven,lineage-specific missing data and significant topological incongruence of individual exon trees,the resulting phylogenies were concordant and successfully resolved the phylogenetic relationships of the Peltigerales.Relationships in the Collematineae were defined by short branches and lower nodal support than in other parts of the tree,due in part to conflicting signal in exon trees,suggesting rapid diversification events in the early evolution of the suborder.Using tree distance measures,we were able to identify a minimum subset of exons that could reconstruct phylogenetic relationships in Peltigerales with higher support than the 125-exon dataset.Comparisons between the minimum and complete datasets in species tree inferences,bipartition analyses,and divergence time estimations displayed similar results,although the minimum dataset was characterized by higher levels of error in estimations of divergence times.Contrasting our inferences from the complete and minimum datasets to those derived from few nuclear and mitochondrial loci reveal that our topology is concordant with topologies reconstructed using the nuclear large subunit and mitochondrial small subunit ribosomal DNA markers,but the target capture datasets had much higher support values.We demonstrated how target capture approaches can effectively decipher ancient rapid radiations in cases where well resolved individual exon trees are sufficiently sampled and how to identify subsets of loci that are appropriate for fungal order-level phylogenetics.

Naming and outline of Dothideomycetes-2014 including proposals for the protection or suppression of generic names

Article 59.1,of the International Code of Nomenclature for Algae,Fungi,and Plants(ICN;Melbourne Code),which addresses the nomenclature of pleomorphic fungi,became effective from 30 July 2011.Since that date,each fungal species can have one nomenclaturally correct name in a particular classification.All other previously used names for this species will be considered as synonyms.The older generic epithet takes priority over the younger name.Any widely used younger names proposed for use,must comply with Art.57.2 and their usage should be approved by the Nomenclature Committee for Fungi(NCF).In this paper,we list all genera currently accepted by us in Dothideomycetes(belonging to 23 orders and 110 families),including pleomorphic and nonpleomorphic genera.In the case of pleomorphic genera,we follow the rulings of the current ICN and propose single generic names for future usage.The taxonomic placements of 1261 genera are listed as an outline.Protected names and suppressed names for 34 pleomorphic genera are listed separately.Notes and justifications are provided for possible proposed names after the list of genera.Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes.A phylogenetic tree based on four gene analyses supported 23 orders and 75 families,while 35 families still lack molecular data.

The Faces of Fungi database:fungal names linked with morphology,phylogeny and human impacts

Taxonomic names are key links between various databases that store information on different organisms.Several global fungal nomenclural and taxonomic databases(notably Index Fungorum,Species Fungorum and MycoBank)can be sourced to find taxonomic details about fungi,while DNA sequence data can be sourced from NCBI,EBI and UNITE databases.Although the sequence data may be linked to a name,the quality of the metadata is variable and generally there is no corresponding link to images,descriptions or herbarium material.There is generally no way to establish the accuracy of the names in these genomic databases,other than whether the submission is from a reputable source.To tackle this problem,a new database(FacesofFungi),accessible at www.facesoffungi.org(FoF)has been established.This fungal database allows deposition of taxonomic data,phenotypic details and other useful data,which will enhance our current taxonomic understanding and ultimately enable mycologists to gain better and updated insights into the current fungal classification system.In addition,the database will also allow access to comprehensive metadata including descriptions of voucher and type specimens.This database is user-friendly,providing links and easy access between taxonomic ranks,with the classification system based primarily on molecular data(from the literature and via updated web-based phylogenetic trees),and to a lesser extent on morphological data when molecular data are unavailable.In FoF species are not only linked to the closest phylogenetic representatives,but also relevant data is provided,wherever available,on various applied aspects,such as ecological,industrial,quarantine and chemical uses.The data include the three main fungal groups(Ascomycota,Basidiomycota,Basal fungi)and fungus-like organisms.The FoF webpage is an output funded by the Mushroom Research Foundation which is an NGO with seven directors with mycological expertise.The webpage has 76 curators,and with the help of these specialists,FoF will provide an updated natural classification of the fungi,with illustrated accounts of species linked to molecular data.The present paper introduces the FoF database to the scientific community and briefly reviews some of the problems associated with classification and identification of the main fungal groups.The structure and use of the database is then explained.We would like to invite all mycologists to contribute to these web pages.

晚白垩世真兽类Zalamdalestes揭示哺乳动物独特的枢椎及其复杂的进化过程

The typical mammalian neck consisting of seven cervical vertebrae(C1–C7)was established by the Late Permian in the cynodont forerunners of modern mammals.This structure is precisely adapted to facilitate movements of the head during feeding,locomotion,predator evasion,and social interactions.Eutheria,the clade including crown placentals,has a fossil record extending back more than 125 million years revealing significant morphological diversification in the Mesozoic.Yet very little is known concerning the early evolution of eutherian cervical morphology and its functional adaptations.A specimen of Zalambdalestes lechei from the Late Cretaceous of Mongolia boasts exceptional preservation of an almost complete series of cervical vertebrae(C2–C7)revealing a highly modified axis(C2).The significance of this cervical morphology is explored utilizing an integrated approach combining comparative anatomical examination across mammals,muscle reconstruction,geometric morphometrics and virtual range of motion analysis.We compared the shape of the axis in Zalambdalestes to a dataset of 88 mammalian species(monotremes,marsupials,and placentals)using three-dimensional landmark analysis.The results indicate that the unique axis morphology of Zalambdalestes has no close analog among living mammals.Virtual range of motion analysis of the neck strongly implies Zalambdalestes was capable of exerting very forceful head movements and had a high degree of ventral flexion for an animal its size.These findings reveal unexpected complexity in the early evolution of the eutherian cervical morphology and suggest a feeding behavior similar to insectivores specialized in vermivory and defensive behaviors in Zalambdalestes akin to modern spiniferous mammals.

子囊菌较担子菌具有更快的进化速率和更高的物种多样性

研究表明,在一些进化分支或有机体之间存在着核苷酸或氨基酸替代速率差异.越来越多的证据表明,种群内的中性分子突变与物种多样化相关.超过98%的陆生真菌属于子囊菌门和担子菌门,而且前者的物种多样性明显多于后者.获得了地衣型真菌红脐鳞的21种蛋白编码基因序列,并应用这些及GenBank中的相关序列进行了随后的分析.建立了3组矩阵:(1)13种真菌,包括105种蛋白编码基因;(2)9种真菌,包括21种蛋白编码基因;(3)299种真菌的nuLSU rDNA序列.应用这些数据,检测了子囊菌门与担子菌门以及子囊菌内部主要纲之间的基因替代速率.蛋白质数据和nuLSU rDNA数据分析显示,子囊菌的基因替代速率显著快于担子菌;而且在子囊菌内部,物种丰富的粪壳菌纲进化速率最快,物种数量较少的锤舌菌纲进化最慢.结果提示,子囊菌的快速进化不是得益于互惠共生、生态条件、无性繁殖、代谢速率或者短世代时间,而可能是由奠基者效应引起的.这是物种数量与进化速率相关的又一证据,与奠基者效应是导致物种丰富的分支进化速率较快的主要原因的假说相吻合.