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1.
Protonympha is an enigmatic fossil represented by two species from the Middle Devonian (Protonympha transversa) and Late Devonian (Protonympha salicifolia) of New York. Although interpreted in the past as a polychaete worm or starfish arm, Protonympha is not found with marine fossils, but with fossil plants. This fossil plant community was a swamp woodland of Lepidosigillaria whitei, with ground cover of Haskinsia colophylla, fringing brackish to freshwater coastal lagoons of the Catskill Delta. Protonympha shares with Ediacaran Vendobionta a quilted body of unskeletonized biopolymer that is unusually resistant to burial compaction. In overall form, Protonympha is most like the Ediacaran genus Spriggina. Protonympha has branching and tapering tubular structures radiating from the bottom. These rhizine‐like structures, thallus stratification and internal chambers revealed by petrographic thin sections suggest affinities with lichenized fungi. As for Cambrian Swartpuntia and Ordovician–Silurian Rutgersella, Protonympha may have been a post‐Ediacaran vendobiont.  相似文献   

2.
《Palaeoworld》2021,30(4):610-626
An assemblage of microfossils of moderate diversity, with the remarkable occurrence of ECAP acritarchs, is reported from the Ediacaran Krol ‘A’ (= the Mahi Formation) succession of Lesser Himalaya, India. Microfossils occur in the chert nodules exposed in Solan district, Himachal Pradesh. Two microfossils, Barogophycus symmetricus n. gen. n. sp. and Botominella lineata are new to the well-established Krol assemblage. The paper concentrates predominantly on fossil eukaryotic filamentous and coccoidal micro-organism of simple morphology. The assemblage is dominated by remains of prokaryotic cyanobacteria and demonstrates the diversity achieved by microorganisms at the beginning of the Ediacaran Period in the aftermath of the Marinoan glaciation. Filamentous and coccoidal microorganisms differ in taxonomic composition from the Mesoproterozoic microbiotas. The Krol microfossils assemblage has biostratigraphic potential and usefulness in broadly demarcating the different levels of the Ediacaran strata. Because of the presence of ECAP acritarchs, along with the appearance of other eukaryotic microorganisms of filamentous and coccoidal morphology, the general level of the Krol ‘A’ assemblage is considered as Ediacaran.  相似文献   

3.
The trace fossil Teisseirei barattinia, found in Cenozoic formations of Uruguay and Argentina, is an elongated chamber recognizable by its depressed cross‐section, antechamber, and its multi‐layered lining with an inner surface texture composed of densely packed sub‐rectangular to sub‐triangular pits. Our recent behavioural observations on larval and pupal stages of Sphingidae (Lepidoptera), particularly on Manduca rustica, suggest that Teisseirei barattinia is the pupation chamber of a sphinx moth. Last instar larvae of Manduca rustica, Eumorpha anchemolus and E. labruscae were placed in terraria to observe their burrowing behaviour and to recover pupation chambers. Chambers show depressed or plane convex cross‐sections as T. barattinia. The internal surface texture of walls is also similar to that of T. barattinia. The same pattern could be obtained experimentally by pressing the true legs of Manduca rustica larva against plasticine. The multi‐layered wall structure, shown by T. barattinia, is a new type of lining for insect trace fossils in palaeosols that result from soil packing combined with discharges of abundant liquid excretion by soft‐bodied larvae, as in the case of Manduca rustica. T. barattinia is the first trace fossil documented in palaeosols attributed to sphinx moths and supported by macro and micromorphological comparisons with extant pupation chambers. The shallow emplacement of moth pupation chambers in soils suggests that T. barattinia would be a good indicator of palaeosol upper horizons.  相似文献   

4.
Rocks of the Ediacaran System (635–541 Ma) preserve fossil evidence of some of the earliest complex macroscopic organisms, many of which have been interpreted as animals. However, the unusual morphologies of some of these organisms have made it difficult to resolve their biological relationships to modern metazoan groups. Alternative competing phylogenetic interpretations have been proposed for Ediacaran taxa, including algae, fungi, lichens, rhizoid protists, and even an extinct higher‐order group (Vendobionta). If a metazoan affinity can be demonstrated for these organisms, as advocated by many researchers, they could prove informative in debates concerning the evolution of the metazoan body axis, the making and breaking of axial symmetries, and the appearance of a metameric body plan. Attempts to decipher members of the enigmatic Ediacaran macrobiota have largely involved study of morphology: comparative analysis of their developmental phases has received little attention. Here we present what is known of ontogeny across the three iconic Ediacaran taxa Charnia masoni, Dickinsonia costata and Pteridinium simplex, together with new ontogenetic data and insights. We use these data and interpretations to re‐evaluate the phylogenetic position of the broader Ediacaran morphogroups to which these taxa are considered to belong (rangeomorphs, dickinsoniomorphs and erniettomorphs). We conclude, based on the available evidence, that the affinities of the rangeomorphs and the dickinsoniomorphs lie within Metazoa.  相似文献   

5.
Abstract: Stegodon protoaurorae sp. nov. (Proboscidea) from the lower Pleistocene Terada Formation of the Kazusa Group in Japan is proposed as a new species based on characteristic features of plate formula, molar size, tooth enamel and plate frequency, and is described herein. The specimen of the new species was transported by autumn storms and buried. The new species fills an evolutionary gap between S. miensis and S. aurorae. Speciation in the lineage from S. miensis through S. protoaurorae to S. aurorae is inferred to have been caused by reduction of terrestrial space during marine transgression. The biostratigraphic distribution of S. protoaurorae suggests intercalation of a new Sprotoaurorae Zone between the Smiensis Zone and the Saurorae Zone. The Sprotoaurorae Zone can be defined in the Nakatsu Group and the Terada Formation of the Kazusa Group, and can be assigned an age of 2.9–2.1 Ma.  相似文献   

6.
Morphologically complex trace fossils, recording the infaunal activities of bilaterian animals, are common in Phanerozoic successions but rare in the Ediacaran fossil record. Here, we describe a trace fossil assemblage from the lower Dunfee Member of the Deep Spring Formation at Mount Dunfee (Nevada, USA), over 500 m below the Ediacaran–Cambrian boundary. Although millimetric in scale and largely not fabric‐disruptive, the Dunfee assemblage includes complex and sediment‐penetrative trace fossil morphologies that are characteristic of Cambrian deposits. The Dunfee assemblage records one of the oldest documented instances of sediment‐penetrative infaunalization, corroborating previous molecular, ichnologic, and paleoecological data suggesting that crown‐group bilaterians and bilaterian‐style ecologies were present in late Ediacaran shallow marine ecosystems. Moreover, Dunfee trace fossils co‐occur with classic upper Ediacaran tubular body fossils in multiple horizons, indicating that Ediacaran infauna and epifauna coexisted and likely formed stable ecosystems.  相似文献   

7.
Mitochondrial 16S rDNA and CO I gene were used as molecular markers for the analysis of the genetic diversity and differentiation of Daphnia galeata populations in nine water bodies in the middle and lower reaches of the Yangtze River. In the combined 16S rDNA and CO I gene sequences, 54 variable sites and 44 haplotypes were observed among 219 individuals belonging to nine D. galeata populations. Average haplotype diversity and nucleotide diversity were, respectively, 0.72% and 0.56%. The F‐statistics (FST) value of the D. galeata populations was 0.149. According to the results of the neutral test, D. galeata in the middle and lower reaches of the Yangtze River had experienced a bottleneck effect in the history. Molecular variance analysis indicated that the genetic differentiation of the D. galeata populations mainly occurred within populations (85.09%). Greater genetic differentiations of D. galeata among individuals within populations appeared in the populations from the Huaihe River basin, whereas smaller genetic differentiations occurred in the populations from the middle reaches of the Yangtze River. Strong gene flows were all observed between Group I (four populations from the middle reaches of the Yangtze River) and Group ΙΙ (three populations from the middle and lower reaches of the Yangtze River), and Group ΙΙΙ (two populations from the Huaihe River basin). The effective migration rates (M) were 851.49 from Group I to Group ΙΙ and 685.96 from Group I to Group ΙΙΙ, respectively. However, no significant relationship was observed between the genetic differentiation and geographical distance of the nine populations (r = .137, p > .05). Results suggested that the genetic differentiation of D. galeata in the water bodies in the middle and lower reaches of the Yangtze River resulted mainly from geographical isolation.  相似文献   

8.
The Cryogenian Period experienced two long lived global glaciations known as Snowball Earths. While these events were dramatic, eukaryotic life persisted through them, and fossil evidence shows that eukaryotes thrived during the c. 30-million-year interlude between the glaciations. Carbonate successions have become an important taphonomic window for this interval. One of the most notable examples is the c. 662–635 Ma Taishir Formation (Tsagaan Olom Group, Zavkhan Terrane, Mongolia) which has yielded a number of eukaryotic fossil taxa. Here, we examine more closely the morphology and taxonomic affinity of some of these Taishir fossils previously interpreted as remains of ciliate tintinnid loricae (purportedly the oldest fossil ciliates). New morphological and ultrastructural analyses indicate that these fossils are not ciliate tintinnids. Instead, we propose a new interpretation: that they are algal reproductive structures related to coeval macroscopic organic warty sheets described as putative red algae. We report the first occurrence of these fossils in the earliest Ediacaran Ol Formation, indicating that this taxon persisted through the Marinoan Snowball Earth. A new interpretation of these fossils as putative red algal spores has broad implications for our understanding of biodiversity in the Neoproterozoic Era, specifically during the Cryogenian Period, and for the antiquity of ciliates.  相似文献   

9.
Twelve Salpichroa taxa have been phytochemically analyzed. From the aerial parts of Sscandens, four known salpichrolides A, C, I, S, and an unreported withanolide named salpichrolide V ( 1 ), were isolated. In Sdependens, Sgayi, Sglandulosa subsp. glandulosa, Sglandulosa subps. weddellii, Sleucantha, Smicrantha, Smicroloba, Sproboscidea, Sramosissima, Stristis var. tristis, and Sweberbauerii, no withanolides were found. The chemical content of ca. 85% of the Salpichroa taxa is in agreement with molecular studies, which suggest that Salpichroa and Jaborosa, a genus considered morphologically close to Salpichroa, are distant in the systematic of the Solanoideae subfamily. Moreover, the in vitro cytotoxic activity of a set of natural salpichrolides and derivatives was examined against two prostate carcinoma cell lines (PC3 and LNCaP) and two human breast cancer cell lines (MCF‐7 and T47D). Several compounds showed moderate activity (IC50 = 64.91 – 29.97 μm ).  相似文献   

10.
11.
A multigene phylogeny using COI‐5P (mitochondrial cytochrome c oxidase subunit 1), psbA (PSII reaction center protein D1), and EF2 (elongation factor 2) sequence data for members of the tribe Corallineae was constructed to assess generic boundaries. We determined that traditional reliance on conceptacle position as an indicator of generic affinities in the Corallineae is not supported and taxonomic changes are required. We found that species currently assigned to Pseudolithophyllum muricatum resolved within the Corallineae in all analyses. This is the first record of crustose members in the subfamily Corallinoideae. Further‐more, the genus Serraticardia was polyphyletic; we propose to synonomize Serraticardia with Corallina, transfer the type species Smaxima to Corallina (Cmaxima (Yendo) comb. nov.), and describe the new genus Johansenia for Smacmillanii (Jmacmillanii (Yendo) comb. nov.). Our molecular data also indicate that species in the genus Marginisporum have evolutionary affinities among species of Corallina and these genera should also be synonymized. This necessitates the combinations Caberrans (Yendo) comb. nov. for Maberrans (Yendo) Johansen & Chihara, Ccrassissima (Yendo) comb. nov. for M. crassissimum (Yendo) Ganesan, and C. declinata (Yendo) comb. nov. for M. declinata (Yendo) Ganesan. Corallina elongata was divergent from all other members of Corallina and is transferred to a new genus, Ellisolandia (E. elongata (J. Ellis & Solander) comb. nov). In addition, COI‐5P and internal transcribed spacer (ITS) data combined with morphological characters were used to establish that rather than the four Corallina species recognized in Canada, there are nine.  相似文献   

12.
《Palaeoworld》2014,23(3-4):209-224
Large acanthomorphic acritarchs have been previously reported from the Ediacaran successions of the Pachmunda and Krol Hill synclines in the Outer Krol Belt of Lesser Himalaya, India. Thin sections of chert from Krol ‘A’ Formation in Khanog and Rajgarh synclines, Outer Krol Belt, record an equally well developed and diversified assemblage of Ediacaran large acanthomorphic acritarchs. This assemblage contains specimens belonging to seven genera and ten species, identified as: Appendisphaera fragilis, A. grandis, Asterocapsoides sp. A, Asterocapsoides sp. B, Cavaspina acuminata, C. basiconica, Eotylotopalla dactylos, Knollisphaeridium sp., Papillomembrana sp., and Weissiella cf. grandistella. It also contains five unnamed forms, viz. A, B, C, D, and E. The Krol acritarch assemblage shows a close resemblance with the Upper Doushantuo or Tanarium anozosTanarium conoideum assemblage of China. However, the absence of biostratigraphically important markers such as Tanarium anozos and T. conoideum from the Krol assemblage, so far, makes it difficult to establish a definite biostratigraphic correlation between the two assemblages. The current observations from this new locality provide additional data for regional and global biostratigraphic correlation, and significantly increase the purview of Ediacaran sequences for global biostratigraphic zonation.  相似文献   

13.
The defatted fractions of the Faramea hyacinthina and Ftruncata (Rubiaceae) leaf MeOH extracts showed in vitro non‐cytotoxic and anti‐dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). Submitting these fractions to the developed RP‐SPE method allowed isolating the antiviral flavanone (2S)‐isosakuranetin‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 1 ) from both species and yielded less active sub‐fractions. The new diastereoisomeric epimer pair (2S) + (2R) of 5,3′,5′‐trihydroxyflavanone‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 2a / 2b ) from Fhyacinthina; the known narigenin‐7‐Oβ‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 3 ) from both species; rutin ( 4 ) and quercetin‐4′‐β‐d ‐O‐glucopyranosyl‐3‐O‐rutinoside ( 5 ) from Fhyacinthina, and kaempferol‐3‐O‐rutinoside ( 6 ), erythroxyloside A ( 7 ) and asperuloside ( 8 ) from Ftruncata have been isolated from these sub‐fractions. Compounds 4  –  8 are reported for the first time in Faramea spp.  相似文献   

14.
Essential oils (EOs) from Schinus molle, Helichrysum gymnocephalum, Cedrelopsis grevei and Melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. EOs were characterized by gas chromatography/mass spectrometry (GC/MS) and quantified by gas chromatography‐flame ionization detection (GC‐FID); then evaluated for their behavioral effects on adults of the green pea aphid Acyrthosiphon pisum (Harris ) using a Perspex four‐armed olfactometer in order to test the compatibility of their use as phytoinsecticides to control this insect pest. Our results showed that the EOs from the leaves of Smolle, Mviridiflora and Cgrevei did not change aphids’ behavior. However, Smolle fruits EO seemed to be attractive while Hgymnocephalum leaves EO exhibited repellency towards aphids at a dose of 10 μl. The major compounds in Smolle fruits EO were 6‐epi‐shyobunol (16.22%) and d ‐limonene (15.35%). While, in Hgymnocephalum leaves EO, 1,8‐cineole was the main compound (47.4%). The difference in aphids’ responses to these two EOs could be attributed to the differences in their compositions. Our findings suggest that these two EOs have potential applications for the integrated pest management of Apisum (Harris ).  相似文献   

15.
16.
Multiple independent and overlapping pollen rejection pathways contribute to unilateral interspecific incompatibility (UI). In crosses between tomato species, pollen rejection usually occurs when the female parent is self‐incompatible (SI) and the male parent self‐compatible (SC) (the ‘SI × SC rule’). Additional, as yet unknown, UI mechanisms are independent of self‐incompatibility and contribute to UI between SC species or populations. We identified a major quantitative trait locus on chromosome 10 (ui10.1) which affects pollen‐side UI responses in crosses between cultivated tomato, Solanum lycopersicum, and Solanum pennelliiLA0716, both of which are SC and lack S‐RNase, the pistil determinant of S‐specificity in Solanaceae. Here we show that ui10.1 is a farnesyl pyrophosphate synthase gene (FPS2) expressed in pollen. Expression is about 18‐fold higher in pollen of S. pennellii than in S. lycopersicum. Pollen with the hypomorphic S. lycopersicum allele is selectively eliminated on pistils of the F1 hybrid, leading to transmission ratio distortion in the F2 progeny. CRISPR/Cas9‐generated knockout mutants (fps2) in S. pennelliiLA0716 are self‐sterile due to pollen rejection, but mutant pollen is fully functional on pistils of S. lycopersicum. F2 progeny of S. lycopersicum × S. pennellii (fps2) show reversed transmission ratio distortion due to selective elimination of pollen bearing the knockout allele. Overexpression of FPS2 in S. lycopersicum pollen rescues the pollen elimination phenotype. FPS2‐based pollen selectivity does not involve S‐RNase and has not been previously linked to UI. Our results point to an entirely new mechanism of interspecific pollen rejection in plants.  相似文献   

17.
We evaluated the antimicrobial activity of 25 monoketone curcuminoids (MKCs) against a representative panel of cariogenic bacteria in terms of their minimum inhibitory concentration (MIC) values. Curcumin A ( 10 ) displayed promising activity against Streptococcus mutans (MIC = 50 μg/ml) and Streptococcus mitis (MIC = 50 μg/ml) as well as moderate activity against Ssanguinis (MIC = 100 μg/ml), Lactobacillus casei (MIC = 100 μg/ml), and Streptococcus salivarius (MIC = 200 μg/ml). Results indicated higher activity of compound 10 than that of its bis‐β‐diketone analog. Additionally, compounds 3a (1,5‐bis(4‐methylphenyl)pentan‐3‐one) and 7b (1,5‐bis(4‐bromophenyl)pentan‐3‐ol) were moderately active against Smitis (MIC = 100 μg/ml) and Ssalivarus (MIC = 200 μg/ml).  相似文献   

18.
During a survey of fungal plant diseases, parasitized uredinial pustules of Coleosporium plumeriae were observed in Umiam, Meghalaya, India. Microscopic examination was conducted using light and scanning electron microscopy which revealed the occurrence of the hyperparasitic hyphomycete Ramularia coleosporii. Molecular characterization using the ITS1‐5.8S‐ITS2 region of nrDNA also confirmed our results. This is the first record of R. coleosporii on C. plumeriae from India.  相似文献   

19.
Four new tirucallane triterpenoids, (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxy‐25‐methoxytirucall‐7‐en‐3‐one ( 2 ), (3S,21S,23R,24S)‐21,23‐epoxy‐21,25‐dimethoxytirucall‐7‐ene‐3,24‐diol ( 8 ), (21S,23R,24R)‐21,23‐epoxy‐24‐hydroxy‐21‐methoxytirucalla‐7,25‐dien‐3‐one ( 11 ), and (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxytirucalla‐7,25‐dien‐3‐one ( 12 ), along with 16 known analogues, 1 , 3  –  7 , 9  –  10 , and 13  –  20 , were isolated from the fruits of Melia azedarach. Their structures were elucidated by spectroscopic methods including 1D‐ and 2D‐NMR techniques and mass spectrometry. These compounds were evaluated for their cytotoxicities against HepG2 (liver), SGC7901 (stomach), K562 (leukemia), and HL60 (leukemia) cancer cell lines. Compound 20 exhibited potent cytotoxicity against HepG2 and SGC7901 cancer cells with the IC50 values of 6.9 and 6.9 μm , respectively.  相似文献   

20.
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