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1.
《Comptes Rendus Palevol》2016,15(5):501-514
Bats (Chiroptera, Mammalia) are a valuable and independent source of palaeoenvironmental information in Quaternary sites because bat assemblages are not necessarily produced by the same processes as those of other small mammals. Here, we report a small collection of bats (MNI 15) from a cave infill of the Aguilón P7 (AGP-7) site (Zaragoza, Spain) dated Late Pleistocene (MIS 3). This is one of the rare localities south of the Ebro River (right bank) with Neanderthal tracks; therefore, the palaeoenvironmental data provided here may help us to understand Neanderthal history. Nine bat taxa were identified, viz. Rhinolophus ferumequinum, Rhipposideros, Myotis gr. myotis/blythii, M. cf. bechsteinii, Memarginatus, Mdaubentonii, Plecotus gr. auritus/austriacus, Hipsugo savii vel. Pipistrellus kuhlii/nathusii, and Miniopterus schreibersii. The presence of a high number of yearlings of the former four species suggests the presence of breeding colonies. The surprisingly high diversity of the sample indicates a variegated vegetation cover and relatively high humidity for the MIS 3 stage in the region.  相似文献   

2.
The first record of milk teeth of South American fossil procyonids comes from the Late Miocene–Early Pliocene at “Farola Monte Hermoso,” Buenos Aires Province, Argentina. Five extant genera of Procyonidae inhabit South America (Bassaricyon Allen, Nasuella Hollister, Potos Geoffroy Saint-Hilaire and Cuvier, Procyon Storr, and Nasua Storr). Of these only Procyon and Nasua are present in the fossil record (Late Pleistocene–Holocene), in several localities in Brazil, Uruguay, and Bolivia. In addition, six other fossil genera were named, but only two are considered valid: Cyonasua and Chapadmalania. Thus, Cyonasua encompasses ten formally named species and Chapadmalania two. The new specimen, MLP 09-X-5-1, is assigned to cf. Cyonasua. In addition, anatomical evidence implies a much more carnivorous diet in Late Miocene–Early Pleistocene procyonids than that of extant South American taxa. Finally, I examine and discuss the “competitive displacement” hypothesis regarding the extinction of native marsupial carnivores after the arrival of immigrant placental carnivores in South America.  相似文献   

3.
Investigation of the Mesozoic seed plant Leptostrobus Heer from the Yangcaogou Formation of the Late Triassic and the Yixian Formation of the Early Cretaceous, Liaoning Province, China, provides new Insight Into Its general morphology and geographical distribution. The materials of L. cancer from the Yixian Formation described herein are later than all the past findings of this species and add to the record of L. cancer during the Early Cretaceous. Based on well-preserved specimens, the specific diagnosis Is slightly emended and the reconstructlon of L. cancer Is perfected. The materials from the Yangcaogou Formation of the Late Triassic are placed in L. spheericus, in addition, we review the history of investigation of the genus Leptostrobus since its establishment in 1876 and discuss the main characteristics of each species.  相似文献   

4.
“Anilioidea” is a likely paraphyletic assemblage of pipe snakes that includes extant Aniliidae from equatorial South America, Uropeltoidea from South and Southeast Asia, and a fossil record that consists primarily of isolated precloacal vertebrae ranging from the earliest Late Cretaceous and includes geographic distributions in North America, South America, Europe, and Africa. Articulated precloacal vertebrae from the middle Eocene Bridger Formation of Wyoming, attributed to Borealilysia nov. gen., represent an unambiguous North American aniliid record and prompts a reconsideration of described pipe snakes and their resultant biogeographic histories. On the basis of vertebral apomorphies, the vast majority of reported fossils cannot be assigned to “Anilioidea”. Instead, most records represent stem taxa and macrostomatans erroneously assigned to anilioids on the basis of generalized features associated with fossoriality. A revised fossil record demonstrates that the only extralimital distributions of fossil “anilioids” consist of the North American aniliid record, and there is no unambiguous fossil record of Old World taxa. The occurrence of aniliids in the mid-high latitudes of the late early Eocene of North America is consistent with histories of northward shifts in equatorial ecosystems during the early Paleogene Greenhouse.  相似文献   

5.
6.
《Comptes Rendus Palevol》2003,2(5):291-297
A new semionotid fish, Lepidotes buddhabutrensis n. sp., is described from the continental Late Jurassic–Early Cretaceous Phu Kradung Formation, Phu Nam Jun, Kalasin Province. L. buddhabutrensis is characterized notably by the pattern of its cheek bones, by its short preorbital region, and by its numerous and well-developed premaxillary teeth. L. buddhabutrensis is provisionally placed in the genus Lepidotes; it shares, however, derived characters with other semionotids, such as Araripelepidotes and Pliodetes. To cite this article: L. Cavin et al., C. R. Palevol 2 (2003).  相似文献   

7.
《Palaeoworld》2015,24(4):479-496
The morphology of the pseudoplanktonic crinoid Traumatocrinus from the early Late Triassic (Carnian) Xiaowa Formation of Guanling County (South China, Guizhou Province) is described based on articulated and disarticulated material. Juvenile individuals of less than 10 mm crown height with 20 isotomously branching arms prove the encrinid ancestry of the family Traumatocrinidae. However, even the smallest individuals have five large interradials. Endotomous branching commences at crowns of slightly more than 10 mm at the outer arms of the rays. All brachial articulations are ligamentary (granosyzygies). The assignment of the Chinese material to one of the nominal species of Traumatocrinus is still left open. The diagnosis of the genus Traumatocrinus is emended. Traumatocrinus lived attached to driftwood and was widespread across the Palaeo-Tethys. In contrast to its benthic encrinid ancestors, Traumatocrinus fixed its distal column with countless anastomosing radicular cirri to its substrate, preferentially to the ends of the driftwood logs. Depending on the state of the hypothesized mutable collagene tissue, the columns are preserved in straight positions or curved like a rope. Crowns are preserved in star position with radially splayed arms or in lateral bell position with the cup disrupted in interbrachial position. As usual in black shales, the exposed upper sides of the crinoids are in a more or less progressive state of decomposition whereas the embedded lower sides are intact.  相似文献   

8.
The First Appearance Datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosaL. ziegleri has been considered the most suitable definition and global correlation-level for a revised base of the Serpukhovian Stage. Abundant specimens of Lochriea are recorded throughout the Late Visean–early Serpukhovian interval in the Naqing section, South China. Among them, the P1 elements, with wide morphological variability, enable confirmation and refinement of main lineages within the genus. Two lineages are proposed: 1) noded Lochriea species, such as L. mononodosaL. nodosaL. ziegleri, L. senckenbergica and L. multinodosa, and 2) ridged Lochriea species such as L. monocostataL. costataL. cruciformis. The possibility for their phylogenetic relationships is evaluated in this paper.  相似文献   

9.
An α-amylase produced by Paecilomyces variotii was purified by DEAE-cellulose ion exchange chromatography, followed by Sephadex G-100 gel filtration and electroelution. The α-amylase showed a molecular mass of 75 kDa (SDS-PAGE) and pI value of 4.5. Temperature and pH optima were 60 °C and 4.0, respectively. The enzyme was stable for 1 h at 55 °C, showing a t50 of 53 min at 60 °C. Starch protected the enzyme against thermal inactivation. The α-amylase was more stable in alkaline pH. It was activated mainly by calcium and cobalt, and it presented as a glycoprotein with 23% carbohydrate content. The enzyme preferentially hydrolyzed starch and, to a lower extent, amylose and amylopectin. The Km of α-amylase on Reagen® and Sigma® starches were 4.3 and 6.2 mg/mL, respectively. The products of starch hydrolysis analyzed by TLC were oligosaccharides such as maltose and maltotriose. The partial amino acid sequence of the enzyme presented similarity to α-amylases from Bacillus sp. These results confirmed that the studied enzyme was an α-amylase ((1→4)-α-glucan glucanohydrolase).  相似文献   

10.
There has been great progress in the development of technology for the conversion of lignocellulosic biomass to sugars and subsequent fermentation to fuels. However, plant lignin remains an untapped source of materials for production of fuels or high value chemicals. Biological cleavage of lignin has been well characterized in fungi, in which enzymes that create free radical intermediates are used to degrade this material. In contrast, a catabolic pathway for the stereospecific cleavage of β-aryl ether units that are found in lignin has been identified in Sphingobium sp. SYK-6 bacteria. β-Aryl ether units are typically abundant in lignin, corresponding to 50–70% of all of the intermonomer linkages. Consequently, a comprehensive understanding of enzymatic β-aryl ether (β-ether) cleavage is important for future efforts to biologically process lignin and its breakdown products. The crystal structures and biochemical characterization of the NAD-dependent dehydrogenases (LigD, LigO, and LigL) and the glutathione-dependent lyase LigG provide new insights into the early and late enzymes in the β-ether degradation pathway. We present detailed information on the cofactor and substrate binding sites and on the catalytic mechanisms of these enzymes, comparing them with other known members of their respective families. Information on the Lig enzymes provides new insight into their catalysis mechanisms and can inform future strategies for using aromatic oligomers derived from plant lignin as a source of valuable aromatic compounds for biofuels and other bioproducts.  相似文献   

11.
Abstract

We here describe new remains of amphibians and reptiles from the early Miocene (MN 4) of two different Greek localities, Aliveri and Karydia. The newly described material consists of urodelans, alytids, indeterminate anurans, turtles, crocodylians, lacertids, indeterminate scincomorphs, anguids, colubrids, viperids, and indeterminate snakes. The presence of the frog Latonia cf. gigantea in Greece is documented for the first time. Additionally, the presence of viperids in Aliveri implies a much wider distribution for these snakes during the early Miocene of Europe. Of special interest is the presence of a peculiar colubrid that seems to possess a hitherto unknown vertebral structure, which is herein defined as the ‘paracentral ridge’. Although incomplete, the new material has important taxonomic and biogeographic implications, as it enhances our understanding of southeastern European herpetofaunas from the early Miocene, a time period that was characterised by major dispersal and extinction events and climatic change that affected the whole continent.  相似文献   

12.
Vanadium and sulphur were found by X-ray microanalysis in three different cell types, morula cells, signet-ring cells, and granular amoebocytes, from each of the ascidians Ascidia mentula (Müller) and Ascidiella aspersa (Müller). In addition to the cells containing vanadium and sulphur a few vacuolar cells containing high concentrations of iron, magnesium and calcium were also found. After fixation in the presence of strontium or barium chlorides another cell type containing large amounts of precipitated sulphur was also found, confirming our previous findings that many haemolymph cells in these species contain large amounts of sulphate only. The presence of these various cell types is discussed in relation to the question of the acidity of ascidian blood cells.  相似文献   

13.
14.
The inclusion of (R)- and (S)-camphor compounds in α-cyclodextrin has been studied by X-ray crystallography. The crystal structures of the complexes reveal that one guest molecule is accommodated inside the cavity formed by a head-to-head cyclodextrin dimer. In the crystal lattice, the dimers form layers which are successively shifted by half a dimer. In both (R)- and (S)-cases, the camphor molecule exhibits disorder and occupies three major sites with orientations that can be described as either ‘polar’ or ‘equatorial’. Molecular dynamics simulations performed for the observed complexes indicate that although the carbonyl oxygen of both (R)- and (S)-camphor switches between different hydrogen bonding partners, it maintains the observed mode of ‘polar’ or ‘equatorial’ alignment.  相似文献   

15.
The genus Pythium, with slightly over 280 described species, has been classified traditionally with other filamentous, coenocytic, sporangia-producing fungi as “Phycomyetes”. However, with recent advances in chemical, ultrastructural and molecular studies, Pythium spp. are now considered as “fungus-like organisms” or “pseudo-fungi” and are placed in the Kingdom Chromista or Kingdom Straminopila, distinct from the true fungi of the Kingdom Fungi or Kingdom Mycota. They are widely distributed throughout the world as soil saprophytes or plant pathogens. Because of the warm moist maritime climate, Taiwan, China, is especially rich in Pythium species. To date, 48 species of Pythium have been reported from Taiwan, China, with the dominant species being Py. vexans, Py. spinosum, Py. splendens, Py. aphanidermatum, Py. dissotocum and Py. acanthicum. There is no definite geographical distribution of Pythium spp. in Taiwan, China. Twenty nine species of Pythium have proven to be plant pathogens attacking a wide variety of woody and herbaceous plants primarily causing pre- and post-emergence seedling damping-off, root rot, stem rot and rotting of fruits, tubers and ginger rhizomes, resulting in serious economic losses. The most important plant pathogenic species include Py. aphanidermatum and Py. Myriotylum, which are most active during the hot and wet summer months; whereas Py. splendens, Py. spinosum, Py. ultimum and Py. irregulare cause the greatest damage in the cool winter. Most Pythium spp. are non-specific pathogens, infecting mainly juvenile or succulent tissues. This review attempts to assess the taxonomic position of the genus Pythium and provide details of the historical development of the study of Pythium as pathogens in Taiwan, China, causing diseases of sugarcane, trees, vegetables, fruits, specialty crops and flowering plants, as well as measures to control these diseases. Of special note is the introduction of the S-H mixture which, when used as soil amendment, effectively controls many soil-borne Pythium diseases during the early stages of plant growth. The diversity of Pythium species in Taiwan, China, is discussed in comparison with the situation in the mainland of China and suggestions are made to fully utilize Pythium spp. as agents for biological control, in industry and medicine.  相似文献   

16.
Remains of Albertona balkanica from the Early Miocene clays of eastern Serbia have shifted the range boundary of this species in direction of Central Europe. The peculiarities in tooth morphology were used for comparison and defining of the possible evolutionary connection with other representatives of fossil Ochotonidae. Due to the similarity with fauna of Aliveri in Greece, the association of small mammals of Snegotin (which includes Albertona) was included in the MN4 zone.  相似文献   

17.
The Upper Cenomanian cover of the Palaeozoic Mouthoumet Massif (southern Corbières, Aude, France), on the southern flank of the Bézu anticline, shows accumulations of large platy corals. However, while being already presented in stratigraphic, palaeoecological and sedimentological contexts, these organisms have not been the subject of a palaeontological study. The coral fauna encompasses 16 species of the families Leptophylliidae, Microsolenidae, and Siderastraeidae and is here presented in detail.  相似文献   

18.
The ichnogenusBalanoglossites Mägdefrau, 1932 is re-described from its type area and is interpreted as part of a complex trace fossil comprising both burrow and boring components. The type ichnospecies,B. triadicus, consists of predominantly deep U- or Y-shaped tunnel elements, whereasB. ramosus n. isp. encompasses irregularly ramified galleries. Both ichnospecies occur frequently in firmground and hardground substrates with sporadic epikarst features. In the underlying softground, they may integrate intoLabyrintichnus terrerensis Uchman &; Álvaro, 2000, a network of irregular galleries and communicating shafts. On the omission surface, the tunnels are linked to elongated or winding grooves in hard or firm substrates. Further elements of the complex trace fossil include lobate burrows similar toZoophycos andRhizocorallium, mainly occurring in firmground and softground, shallow to deep U-shaped pouches and winding tunnels (Maeandropolydora sulcans Voigt, 1965) in hard and firm substrates. Finally, some tunnel portions and well preserved top surfaces of the ichnofabrics are scattered with the faecal pelletsCoprulus oblongus Mayer, 1952.C. oblongus has a rounded shape and a homogeneous structure and belongs to the Coprulidae n. ichnofam. Based on the numerous fingerprints preserved in the complex trace fossil, polychaete worms are identified as possible tracemakers. This is in accordance with the close combination of borings and burrows, a tunnel system highly variable in shape and size, blind ending side-branches and tunnel terminations, association with scolecodonts and exceptionally preserved polychaete remains. In addition, different commensals may have contributed to the modification of the complex trace fossil.  相似文献   

19.
To clarify the mechanism for substrate recognition of α-aminoadipate aminotransferase (AAA-AT) from Thermus thermophilus, the crystal structure of AAA-AT complexed with N-(5′-phosphopyridoxyl)-l-glutamate (PPE) was determined at 1.67 Å resolution. The crystal structure revealed that PPE is recognized by amino acid residues the same as those seen in N-(5′-phosphopyridoxyl)-l-α-aminoadipate (PPA) recognition; however, to bind the γ-carboxyl group of Glu at a fixed position, the Cα atom of the Glu moiety moves 0.80 Å toward the γ-carboxyl group in the PPE complex. Markedly decreased activity for Asp can be explained by the shortness of the aspartyl side chain to be recognized by Arg23 and further dislocation of the Cα atom of bound Asp. Site-directed mutagenesis revealed that Arg23 has dual functions for reaction, (i) recognition of γ (δ)-carboxyl group of Glu (AAA) and (ii) rearrangement of α2 helix by changing the interacting partners to place the hydrophobic substrate at the suitable position.  相似文献   

20.
A water-soluble immunoenhancing polysaccharide was isolated from the aqueous extract of fruit bodies of somatic hybrid (Pflo Vv5 FB), obtained through protoplast fusion between Pleurotus florida and Volvariella volvacea strains. On the basis of acid hydrolysis, the polysaccharide was found to contain glucose only. Methylation analysis, periodate oxidation along with 1H, DEPT-135, and 13C NMR spectroscopy, including two-dimensional TOCSY, DQF-COSY, NOESY, ROESY, 1H,13C-HMQC, and HMBC experiments showed that the polysaccharide was a (1→6)-β-d-glucan, which was not a constituent of any of the parent mushrooms previously reported.This glucan stimulated the macrophages, splenocytes, and thymocytes.  相似文献   

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