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1.

Background

Sauropterygia is an abundant and successful group of Triassic marine reptiles. Phylogenetic relationships of Triassic Sauropterygia have always been unstable and recently questioned. Although specimens occur in high numbers, the main problems are rareness of diagnostic material from the Germanic Basin and uniformity of postcranial morphology of eosauropterygians. In the current paper, morphotypes of humeri along with their corresponding bone histologies for Lower to Middle Muschelkalk sauropterygians are described and interpreted for the first time in a phylogenetic context.

Methodology/Principal Findings

Nothosaurus shows a typical plesiomorphic lamellar-zonal bone type, but varying growth patterns and the occurrence of a new humerus morphotype point to a higher taxonomic diversity than was known. In contrast to the enormous morphological variability of eosauropterygian humeri not assigned to Nothosaurus, their long bone histology is relatively uniform and can be divided into two histotypes. Unexpectedly, both of these histotypes reveal abundant fibrolamellar bone throughout the cortex. This pushes the origin of fibrolamellar bone in Sauropterygia back from the Cretaceous to the early Middle Triassic (early Anisian). Histotype A is assigned to Cymatosaurus, a basal member of the Pistosauroidea, which includes the plesiosaurs as derived members. Histotype B is related to the pachypleurosaur Anarosaurus. Contrary to these new finds, the stratigraphically younger pachypleurosaur Neusticosaurus shows the plesiomorphic lamellar-zonal bone type and an incomplete endochondral ossification, like Nothosaurus.

Conclusions/Significance

Histological results hypothetically discussed in a phylogenetical context have a large impact on the current phylogenetic hypothesis of Sauropterygia, leaving the pachypleurosaurs polyphyletic. On the basis of histological data, Neusticosaurus would be related to Nothosaurus, whereas Anarosaurus would follow the pistosaur clade. Furthermore, the presence of fibrolamellar bone, which is accompanied with increased growth rates and presumably even with increased metabolic rates, already in Anarosaurus and Cymatosaurus can explain the success of the Pistosauroidea, the only sauropterygian group to survive into the Jurassic and give rise to the pelagic plesiosaur radiation.  相似文献   

2.
The holotype ofAnarosaurus multidentatus von Huene (1958) from the lowermost Anisian of the Austrian Alps is redescribed and referred to the genusCymatosaurus. Eusauropterygian characters shared byA. multidentatus are the elongated and broadened Symphysis, and the contours of the lower jaw suggesting the presence of a constricted snout. Morphological details of the lower jaw Symphysis showA. multidentatus to be close toCymatosaurus among stem-group sauropterygians.Cymatosaurus multidentatus is the only representative of its genus known so far from the Alpine Triassic, and it represents the earliest known sauropterygian from the Alpine Triassic.  相似文献   

3.
Proyseria decora (Dujardin, 1845) (the type-species of the genus Proyseria Petter, 1959) is redescribed on the basis of specimens from Alcedo atthis (L.) (Coraciiformes: Alcedinidae) from Iran. P. petterae n. sp. is described from Corythornis vintsioides (Eydoux & Gervais) (Alcedinidae) from Madagascar by light and scanning electron microscopy. Proyseria sp. from Alcedo euryzona Temminck from continental Malaysia is described on the basis of a single male specimen. Stegophorus alcedonis Puqin, Yanyin & Guocal, 1991 from A. atthis in China is transferred to the genus Proyseria as P. alcedonis n. comb. The generic diagnosis of Proyseria is amended. Review of the species of the genera Proyseria and Stegophorus Wehr, 1934 is presented.  相似文献   

4.
Wei B  Yu X  Zhang S  Gu L 《Microbiological research》2011,166(6):468-474
Some common floating aquatic macrophytes could remove nutrients, such as nitrogen, from eutrophic water. However, the relationship between these macrophytes and the ammonia-oxidizing microorganisms on their rhizoplanes is still unknown. In this study, we examined communities of ammonia-oxidizing archaea (AOA) and bacteria (AOB) on the rhizoplanes of common floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Ipomoea aquatic) in a eutrophic reservoir.The results show that AOB were the predominant ammonia-oxidizer on the three rhizoplanes. The principal AOB were Nitrosomonas europaea and Nitrosomonas ureae clades. The principal group of AOA was most similar to the clone from activated sludge. The ratio of AOB amoA gene copies to AOA varied from 1.36 (on E. crassipes) to 41.90 (on P. stratiotes). Diversity of AOA was much lower than that of AOB in most samples, with the exception of P. stratiotes.  相似文献   

5.
Reversible thermal denaturation of cytochrome c-552 from the extremely thermophilic bacterium Thermus thermophilus was studied by circular dichroism and fluorescence spectroscopy. Thermal denaturation in the presence of guanidine hydrochloride is completely reversible. The thermodynamic parameters for the reaction have been calculated based on a two-state mechanism. The free energy change on denaturation (ΔG) at 25 °C in the absence of denaturant is estimated to be 28.5 ± 0.15 kcal/mol, which is larger than that of cytochrome c from mesophilic organisms. The temperature of maximum stability is approximately 27 °C, which is higher than those of cytochromes c from mesophilic organisms (9 to 12 °C). The temperature dependences of the enthalpy and entropy changes are similar to those of cytochromes c from mesophilic organisms. The heat capacity change on denaturation is between 1250 and 1680 cal/deg mole, which is similar to those of cytochromes c from mesophilic organisms (1500 to 2500 cal/deg mol). From these results, it has been concluded that T. thermophilus cytochrome c is more stable than cytochromes c from mesophilic organisms by virtue of the fact that the free energy change for denaturation is greater and has its maximum at a higher temperature.  相似文献   

6.
The fauna of quill mites of the family Syringophilidae Lavoipierre, 1953 (Acari: Prostigmata Cheyletoidea) parasitising birds of the family Rallidae Vigors (Gruiformes) is updated. A new species, Rafapicobia melzeri n. sp. (subfamily Picobiinae), is described from four host species: Rallus aquaticus Linnaeus (type-host) from Germany, Pardirallus sanguinolentus (Swainson) from Chile, Porzana porzana (Linnaeus) from France and P. parva (Scopoli) from Kirghizia. The new species is most similar to R. lepidocolaptesi Skoracki & Solarczyk, 2012 but differs in the absence of agenital plates and the length ratios of setae ag2:g1 and vi:ve:si in females and in the punctate ornament on the hysteronotal and the pygidial shields in males. A key to the species of the genus Rafapicobia is proposed. This is the first record of a representative of the subfamily Picobiinae on gruiform birds. Additionally, new rallid hosts are reported for Charadriphilus ralli Skoracki & Bochkov, 2010 (subfamily Syringophilinae): Gallinula melanops (Vieillot) from Chile, Laterallus melanophaius (Vieillot) from Paraguay, and P. parva (Scopoli) from Kirghizia.  相似文献   

7.
A new species of proteocephalid cestodes, provisionally assigned to the polyphyletic genus Ophiotaenia La Rue, 1911 (Cestoda: Proteocephalidae), is described from Compsophis infralineatus (Günther) (Serpentes: Pseudoxyrhophiidae) endemic to Madagascar. Ophiotaenia oreae n. sp. differs from all African and Asian species of Ophiotaenia by possessing more uterine diverticula (68–82 on one side). It is also characterised by the absence of an apical organ, the relative sizes of the cirrus-sac and ovary, the almost equatorial position of the gonopore, the diameter of the embryophore, and other biometric characteristics. Phylogenetic relationships of the new species indicate its relatedness to Indomalayan and Australasian proteocephalids from reptiles. Ophiotaenia oreae n. sp. formed a well-supported clade composed of species of Australophiotaenia de Chambrier, Beveridge and Scholz, 2018 from Australian snakes, Macrobothriotaenia ficta (Meggitt, 1931) from Xenopeltis unicolor Reinwardt in Boie from Vietnam, Ophiotaenia sp. from Trimeresurus flavomaculatus (Gray) from the Philippines, and Ophiotaenia bungari de Chambrier, Binh and Scholz, 2012 from Bungarus fasciatus (Schneider) from Vietnam. The only proteocephalid from Madagascan snakes sequenced so far, Ophiotaenia lapata Rambeloson, Ranaivoson and de Chambrier, 2012 from Madagascarophis colubrinus (Schlegel), does not form a monophyletic group with the new species. The actual species diversity of reptilian cestodes in Madagascar is undoubtedly underestimated. Because of the assumed strict (oioxenous) host specificity of reptilian proteocephalids and rich fauna of snakes occurring in Madagascar, it is plausible to expect the existence of dozens new species of proteocephalids on this island.  相似文献   

8.
《Journal of Asia》2020,23(3):791-796
The fairyfly Anagrus (Anagrus) japonicus Sahad (Hymenoptera: Mymaridae) is identified for the first time as an egg parasitoid of the okra leafhopper Amrasca (Sundapteryx) biguttula (Ishida) (Hemiptera: Cicadellidae) on Okinawa Island, Japan. Amrasca biguttula is a serious pest of okra, Abelmoschus esculentus (L.) Moench (Malvaceae), both in Okinawa and Bonin Islands. Female of A. japonicus is redescribed, and its previously unknown male is described, based on the reared specimens from Okinawa. Prior to this study, host associations of A. japonicus were unknown. Another species of Mymaridae, Arescon enocki (Subba Rao and Kaur), also emerged from eggs of A. biguttula on okra in Okinawa, albeit in much smaller numbers.  相似文献   

9.
Panaqolus tankei is described from the Xingu River, Brazil. The new species is diagnosed from P. albomaculatus, P. dentex, P. nix, P. nocturnus, and P. koko by its color pattern consisting of dark and light diagonal bars on the body and bands on the fins (vs. body and fins without bars or bands); from P. albivermis, P. maccus, and P. purusiensis by the width of the dark bars being more or less the same of the light bars (vs. dark bars at least two or three times wider than light bars) and from P. changae by the absence of vermiculation on the head (vs. vermiculation present on head). The new species differs from P. gnomus by the orientation of the bars from posterodorsal to anteroventral direction (vs. anterodorsal to posteroventral direction), and from P. claustellifer by the orientation of the bands in the dorsal fin that are not parallel to the margin (vs. parallel to the margin). The barcoding region (COI) was sequenced for the new species, sequences were deposited in GenBank and were compared with congeners from other drainages. With regard to the current construction of a hydroelectric power plant (a so-called mega dam) in the Xingu River, herewith we increase knowledge of the river Xingu’s ichthyofauna and, thus improve the assessment of the impacts of that construction on the river.  相似文献   

10.
The male genitalia of Chrysopolomidae were found to include by nine pairs of muscles: m1, m2(10), m3(2), m4, m5(7), m6(5), m7(6), m8(3), m20, and the unpaired muscle m21, fully corresponding to their ground plan in Zygaenoidea. The archaic muscles m20 were found in both Chrysopolomidae and Limacodidae, for the first time for the superfamily Zygaenoidea. Muscles m3(2) and m4 in all the studied chrysopolomids are attached to the base of a gnathos-like complex sclerite, which proves its origin from the transtilla. The genital apparatus of Chrysopolomidae and its muscles are completely symmetrical. The bases of intravalval muscles m5(7) have moved from the sacculus to the juxta; this feature is not found in any other related family of the limacoid complex. The gnathos of Chrysopolomidae is reduced and functionally replaced by the transtilla separated from the valvae; some parts of the true gnathos may be incorporated in the gnathos-like structure of the transilla. A characteristic feature is the presence of strong muscles m3(2), which are reduced in all the studied limacodids. These muscles are running from the modified transtilla deep inside the uncus and provide not the abduction of the valvae but the depression of the uncus and the lifting of the arms of the transtilla. Thus, Chrysopolomidae are morphologically separated from Limacodidae; it is suggested that the former group should be treated as a separate family closely related to Limacodidae. The tribe Achroceridini is transferred from Chrysopolominae into Ectropinae based on the similar structure of the male genitalia and the presence of two pairs of spurs on the hind tibia.  相似文献   

11.
Dexosarcophaga tupinamba n. sp. is described based on male specimens from the Brazilian states of Pará and Maranhão; Dexosarcophaga bermudezi Silva & Mello-Patiu is newly recorded from Pará and South America; and Dexosarcophaga avispaensis Mello is newly recorded from Pará (new to Brazil). The Brazilian species Dexosarcophaga limitata (Lopes) and Dexosarcophaga pusilla (Lopes) are both recorded from Pará, which are new records from the Brazilian Amazon, Dexosarcophaga aurifacies (Lopes) is newly recorded from the state of Alagoas and Dexosarcophaga carvalhoi (Lopes) is newly recorded from the states of Mato Grosso, Maranhão, and Pará. A key to the identification of males of the subgenus Bezzisca is provided.  相似文献   

12.
13.
A new cyclopoid species of the genus Neocyclops Gurney, 1927 is described. Type specimens were collected from a beach on south-western coast of the Korean Peninsula by rinsing intertidal coarse sandy sediments. Neocyclops hoonsooi sp. n. is most characteristic in showing the conspicuous chitinized transverse ridges originating from the medial margins of the coxae of all swimming legs. The new species is most similar to Neocyclops vicinus, described from the Brazilian coast, and Neocyclops petkovskii, from Australia. All three species share a large body size (more than 750 µm long), the presence of an exopodal seta on the antenna, two setae on the mandibular palp, the same seta/spine armature on the third endopodal segment of leg 3 (3 setae + 3 spines), and the fairly long inner distal spine on the third endopodal segment of the female leg 4. However, Neocyclops hoonsooi sp. n. differs from both species by the much shorter caudal rami (less than 1.7 times as long as wide) and the shorter dorsal caudal seta VII. Furthermore, Neocyclops hoonsooi is clearly distinguished from Neocyclops vicinus by the 10-segmented antennule (vs 12 segments in Neocyclops vicinus), and from Neocyclops petkovskii by the elongate inner distal spine on leg 5 exopod and the 3-segmented leg 5 in male (vs 4-segmented in Neocyclops petkovskii). A tabular comparison of characters separating Neocyclops hoonsooi from its closest allies and a key to Neocyclops species from the Indo-Pacific Ocean are provided. This is the first record of the genus Neocyclops from the northern Pacific.  相似文献   

14.
15.
16.
A new hermit crab species of the family Paguridae, Tomopaguropsis ahkinpechensis sp. n., is described from deep waters (780–827 m) of the Gulf of Mexico. This is the second species of Tomopaguropsis known from the western Atlantic, and the fifth worldwide. The new species is morphologically most similar to a species from Indonesia, Tomopaguropsis crinita McLaughlin, 1997, the two having ocular peduncles that diminish in width distally, reduced corneas, dense cheliped setation, and males lacking paired pleopods 1. The calcified figs on the branchiostegite and anterodorsally on the posterior carapace, and the calcified first pleonal somite that is not fused to the last thoracic somite, are unusual paguroid characters. A discussion of the affinities and characters that define this new species is included, along with a key to all five species of Tomopaguropsis.  相似文献   

17.
Plasmodium simium is a parasite from New World monkeys that is most closely related to the human malaria parasite Plasmodium vivax; it also naturally infects humans. The blood-stage infection of P. vivax depends on Duffy binding protein II (PvDBPII) and its cognate receptor on erythrocytes, the Duffy antigen receptor for chemokines (hDARC), but there is no information on the P. simium erythrocytic invasion pathway. The genes encoding P. simium DBP (PsDBPII) and simian DARC (sDARC) were sequenced from Southern brown howler monkeys (Alouatta guariba clamitans) naturally infected with P. simium because P. simium may also depend on the DBPII/DARC interaction. The sequences of DBP binding domains from P. vivax and P. simium were highly similar. However, the genetic variability of PsDBPII was lower than that of PvDBPII. Phylogenetic analyses demonstrated that these genes were strictly related and clustered in the same clade of the evolutionary tree. DARC from A. clamitans was also sequenced and contained three new non-synonymous substitutions. None of these substitutions were located in the N-terminal domain of DARC, which interacts directly with DBPII. The interaction between sDARC and PvDBPII was evaluated using a cytoadherence assay of COS7 cells expressing PvDBPII on their surfaces. Inhibitory binding assays in vitro demonstrated that antibodies from monkey sera blocked the interaction between COS-7 cells expressing PvDBPII and hDARC-positive erythrocytes. Taken together, phylogenetic analyses reinforced the hypothesis that the host switch from humans to monkeys may have occurred very recently in evolution, which sheds light on the evolutionary history of new world plasmodia. Further invasion studies would confirm whether P. simium depends on DBP/DARC to trigger internalization into red blood cells.  相似文献   

18.
A new species of Grillotia, G. gastrica n. sp., is described from the stomach musculature of the teleosts Upeneichthys lineatus (Bloch & Schneider) and Sillaginodes punctatus (Cuvier) from off Perth, Western Australia. The new species most closely resembles G. pristiophori Beveridge & Campbell, 2001 in having six hooks in each principal row of the metabasal tentacular armature but differs in having a smooth scolex tegument and in having a band of hooklets running the entire length of the external surface of the tentacle rather than diminishing in width to a single hooklet as occurs in G. pristiophori. Grillotia heptanchi (Vaullegeard, 1899) is redescribed and the details of the mature segment are described for the first time. Grillotia adenoplusius (Pintner, 1903) is redescribed from the type-specimens and is considered to be the larval stage of G. acanthoscolex Rees, 1944 (syns G. spinosissima Dollfus, 1969 and G. microthrix Dollfus, 1969). The adult of G. adenoplusius is also redescribed based on the types of G. spinosissima. The type-specimens of G. dolichocephala Guiart, 1935 and G. minor Guiart, 1935 were re-examined and G. minor is considered to be a synonym of G. dolichocephala as is G. meteori Palm & Schröder, 2001. Based on an examination of the type-specimens, G. scolecina (Rudolphi, 1819) is treated as a species inquirenda. A list is provided of the species currently placed in Grillotia.  相似文献   

19.
Peterson PA 《Genetics》1976,84(3):469-483
From an original A2 allele (colored aleurone), a mutable allele, a2-m-4 1629, that changes from a2 to A2 is described. Mutability is expressed as a very distinct pattern limited to the last cell division.—The mutability of a2-m-4 1629 is autonomously controlled by an En at the a2 locus. This En, inactive on standard a testers for En, is partially active on a2-m-1, an a2 tester for En, and expresses varied levels of activity from limited to nearly full suppression of the a2-m-1 color phenotype.—When the En of the a2-m-4 1629 allele transposes from the a2 locus, it behaves, at the new position, like a standard En in triggering a2-m-1, a-m-1 and a-m(r), which express colored spots on a colorless background. The activity of En is therefore different following the change in chromosome location. This finding supports the "position" hypothesis that has been proposed to explain diverse patterns observed among controlling elements. In this case mutation is related to the terminal cell state and not to tissue differences as shown with some phase-variation regulatory elements.  相似文献   

20.
Fusarium pseudograminearum (Fp) is a stubble-borne fungus that causes crown rot in wheat and barley. Displacement of Fp from stubble by other fungi was explored. Fungi were isolated from field collections of stubble and identified using morphological and molecular methods. The most abundant species were Alternaria sp., Sterile sp. 1 and Fp. Representative isolates of all species were screened in dual culture with Fp to select candidates for detailed experiments on displacement. Trichoderma harzianum (Th), Alternaria infectoria (Ai), Fusarium equiseti (Fe) and Fusarium nygamai (Fn) were chosen as representing the range of interaction types found. The effects of temperature (5–35 °C) and water potential (?0.3 to ?5 MPa) on growth rates, displacement of Fp from infested barley straw and dual culture interaction with Fp were determined. Th was the strongest antagonist overall, but displaced Fp very poorly at the lowest temperatures and water potentials. It was more antagonistic than expected from effects on growth at high temperature and less antagonistic than expected at low temperature. Fe and Fn showed consistent mutual antagonism with Fp on contact in dual culture and gave moderate displacement of Fp from straw, with Fe being the most effective antagonist under cool dry conditions. Ai gave very poor displacement of Fp from straw, despite being the most common straw fungus, confirming that displacement was due to antagonism and not just the presence of other fungi. The type of interaction in dual culture was consistent with degree of displacement from straw and could be used to indicate which environmental conditions were most limiting for an antagonist. The ability to displace Fp under cool dry conditions appears to be critical.  相似文献   

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