A fossil bee from Early Cretaceous Burmese amber

The bee fossil record is fragmentary, making it difficult to accurately estimate the antiquity of bee-mediated pollination. Here, we describe a bee fossil [Melittosphex burmensis (new species), Melittosphecidae (new family)] from Early Cretaceous Burmese amber (approximately 100 million years before the present). The fossil provides insights into the morphology of the earliest bees and provides a new minimum date for the antiquity of bees and bee-mediated pollination.     

A diverse assemblage of Late Cretaceous dinosaur and bird feathers from Canadian amber

The fossil record of early feathers has relied on carbonized compressions that lack fine structural detail. Specimens in amber are preserved in greater detail, but they are rare. Late Cretaceous coal-rich strata from western Canada provide the richest and most diverse Mesozoic feather assemblage yet reported from amber. The fossils include primitive structures closely matching the protofeathers of nonavian dinosaurs, offering new insights into their structure and function. Additional derived morphologies confirm that plumage specialized for flight and underwater diving had evolved in Late Cretaceous birds. Because amber preserves feather structure and pigmentation in unmatched detail, these fossils provide novel insights regarding feather evolution.     

Carnivorous mushrooms

Ten species of gilled fungi, including the oyster mushroom (Pleurotus ostreatus), have been shown to attack and consume nematodes. It is suggested that these wood-decay fungi utilize the nutrients in their prey to supplement the low levels of nitrogen available in wood. This mode of nutrition is similar in principle to that of carnivorous higher plants.     

A Cretaceous hoofed mammal from India

The sedimentary record documenting the northward drift of India (Late Cretaceous to late Early Eocene) has recently provided important clues to the evolution, radiation, and dispersal of mammals. Here, we report a definitive Late Cretaceous (Maastrichtian) archaic ungulate (Kharmerungulatum vanvaleni genus et species nova) from the Deccan volcano-sedimentary sequences exposed near Kisalpuri village in Central India. This find has important implications for the origin and diversification of early ungulates and raises three possible paleobiogeographic scenarios: (i) Archaic ungulates may have been cosmopolitan in distribution. (ii) Kharmerungulatum might be an immigrant from Western Asia. (iii) Archaic ungulates may have originated in India.     

Lepidoptera in cretaceous amber

The discovery of the head capsule of a lepidopterous larva in Canadian amber of the Cretaceous period is the first fossil evidence of Lepidoptera before the Tertiary period.     

Glomalean fungi from the Ordovician

Fossilized fungal hyphae and spores from the Ordovician of Wisconsin (with an age of about 460 million years) strongly resemble modern arbuscular mycorrhizal fungi (Glomales, Zygomycetes). These fossils indicate that Glomales-like fungi were present at a time when the land flora most likely only consisted of plants on the bryophytic level. Thus, these fungi may have played a crucial role in facilitating the colonization of land by plants, and the fossils support molecular estimates of fungal phylogeny that place the origin of the major groups of terrestrial fungi (Ascomycota, Basidiomycota, and Glomales) around 600 million years ago.     

春兰菌根真菌的筛选

地生兰组织培养存在移栽无菌苗成活率低、生长缓慢、开花迟缓、花小甚至不开花等问题,这些与缺少共生的菌根真菌有关。用分离自云南保山、大理等地野生春兰菌根中的内生真菌19个菌株接种春兰组培幼苗,经4.5个月的共生培养,兰苗叶色正常,根系生长良好。测定植物生长量,从长势有明显提高的接菌苗进行重分离及菌根的显微结构观察,确定春兰菌根的形成,并筛选出春兰的有效共生菌根真菌为CLB111,CLB113和MLX102。通过接种处理后春兰苗的鲜重增长率分别为70.6%、70.2%、68.6%,而不接菌的对照仅为45.6%,与对照差异达0.01极显著水平。结果表明这3个菌株均为春兰的菌根真菌的优良菌株.     

薯蓣内生真菌的分离及其抑制植物病原真菌的活性

从盾叶薯蓣(Dioscorea zingiberensis C.H.Wright)各部位共分离到50株内生真菌,初步鉴定有19株分属于曲霉属(Aspergillus Micheli ex Fr.)、须壳霉属(Pyrenochaetade Not)、刺孢壳属(Chaetomella Fuckel)、侧孢霉属(Sporotrichum Lk.ex Fr.)、棒束梗霉属(Isaria Pers.ex Fr.)、假黑粉霉属(Coniosporium Lk.ex Fr.)和简梗孢霉属(Chromosporium Corda),其余菌株因不产孢而暂未鉴定。利用生长速率法和孢子萌发法检测到分离于根茎的EDT3、EDT4、EDT5和分离于种子的EDS1、EDS3、EDS4等6株菌株的发酵液对棉花黄萎病菌(Verticillium dahliaeKleb.)等6种植物病原真菌的菌丝生长有抑制作用,其中EDS3和EDS4发酵液的混合液E-y对这6种植物病原真菌的菌丝生长和孢子萌发均有较强的抑制作用。     

香蕉吸芽苗内生真菌及其根际土壤真菌的鉴定

从香蕉吸芽苗的根、叶等组织内分离到11个属的真菌:曲霉属(Aspergillus)、炭疽菌属(Colletotrichum)、镰孢属(Fu-sarium)、胶帚霉属(Gliocladium)、木霉属(Trichoderma)、球二孢属(Botryodiplodia)、丝核菌属(Rhizoctonia)、单格孢属(Ulo-cladium)、散子囊菌属(Eurotium)、直双孢属(D idymaria)和丝葚霉属(Papuladpora)。炭疽菌属为优势菌,占内生真菌分离物总数的50%。从香蕉吸芽苗根际土壤中分离到10个属的真菌:曲霉属、镰孢属、木霉属、丝核菌属、毛霉属(Mucor)、青霉属(Penicillium)、拟青霉属(Paecilomyces)、帚霉属(Scopulariopsis)、球壳孢属(Sphaeropsis)和盾壳霉属(Coniothyrium)。拟青霉属、青霉属和毛霉属为优势菌,分别占根际土壤真菌分离物总数的39.7%、23.8%和17.5%。     

Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.     

A precocial avian embryo from the Lower Cretaceous of China

An embryo of an enantiornithine bird has been recovered from the Lower Cretaceous rocks of Liaoning, in northeast China. The bird has a nearly complete articulated skeleton with feather sheet impressions and is enclosed in egg-shaped confines. The tucking posture of the skeleton suggests that the embryo had attained the final stage of development. The presence of well-developed wing and tail feather sheets indicates a precocial developmental mode, supporting the hypothesis that precocial birds appeared before altricial birds.     

茶树内生真菌的分离条件

从茶树里分离出内生真菌,对分离条件进行初步的研究,确定了3%的次氯酸钠作为其主要的表面消毒剂,成熟叶片表面消毒的最佳时间为5 min;采用PDA为一般培养的最适培养基.对所获得的菌株进行纯化,根据描述的菌种特征,索引分析相关文献,鉴别出优势内生真菌分别属于球座菌属(Guignnatdia sp.)、拟盘多毛孢属(Pes...     

Invasion and extinction in the west Indian ant fauna: evidence from the dominican amber

Of 37 genera and well-defined subgenera identified in the amber of the Dominican Republic (late Oligocene or early Miocene), 34 have survived somewhere in the New World tropics to the present, although the species studied thus far are extinct. Of the surviving genera and subgenera, 22 persist on Hispaniola. Fifteen genera and subgenera have colonized the island since amber times, restoring the number of genera and well-defined subgenera now present on Hispaniola to 37. A higher extinction rate has occurred in genera and subgenera that are either highly specialized or possess less colonizing ability, as evidenced by their restriction to the New World.     

莫干山的大型真菌资源

１９９３－１９９７年间,对莫干山的大型真菌进行了调查,共鉴定标本８７种,隶属于８目２０科４５属,其中食用菌３３种,药用菌１７种,毒菌５种。记述了真菌名录,经济意义及分布特点,为浙江省首次发表。     

云杉木质素高降解的菌株筛选

以新疆南山、库尔德宁等地区感染白腐病的雪岭云杉为材料,从中分离得到4株具有木质素降解能力的真菌,并确定其分类学地位,初步研究菌株对木质素的降解能力。通过含有0.04%愈创木酚的马铃薯培养基进行初筛,含有1%的苯胺蓝的马铃薯培养基进行复筛,扫描电镜观察法及称重法对木质素降解能力进行初步测定,得到2-A、1-G、2-B、3-E四种菌,对木质素降解率分别为5.82%、6.23%、3.80%、5.14%。18S r DNA序列分析确定2-A在分类学上属于葡萄座腔菌目,葡萄座腔菌科,微壳色单隔孢属(Microdiplodia sp.); 1-G为三隔镰孢菌(Fusarium tricinctum),镰孢菌属(Fusarium)。     

Cretaceous, Paleocene, and Pleistocene Sediments from the Indian Ocean

Two deep-sea cores containing Cretaceous, Paleocene, and Pleistocene sediments from an oceanic rise approximately 500 miles southeast of Cape Town contained well-preserved fossil foraminiferal ooze made up of about 97 percent planktonic forms, including species of Guembelina and Hedbergella. High percentages of particles less than 53 micro in diameter in the Cretaceous and Paleocene sediments indicate a deep-water open-ocean depositional environment. These sediments are the oldest recovered so far from the Indian Ocean.     

3种淡水肉食性鱼类肝细胞的显微观察及比较

对翘嘴鲌、大鳍鳠和斑鳜3种淡水肉食性鱼类的肝细胞进行了显微观察及比较.结果表明:翘嘴鲌肝细胞分界明显,偶见双核肝细胞,多列肝细胞组成肝细胞索,以中央静脉为中心呈不规则放射状排列;大鳍鳠肝细胞分界较为明显,肝细胞索可见,相互吻合成网,以中央静脉为中心排列;斑鳜肝细胞分界不明显,不能分辨肝细胞索,肝细胞聚集成团块状.3种鱼肝细胞体积较大,核仁大而明显,糖原储藏能力较强,脂质丰富.根据脂肪含量,翘嘴鲌肝细胞分为少脂肝细胞(less-adipose hepatocyte)和拟脂肝细胞(adipose-cell-like hepatocyte);大鳍鳠和斑鳜肝细胞分为少脂肝细胞和多脂肝细胞(more-adipose hepatocyte);少脂肝细胞由节肢动物肝脏的胚细胞演化而来,拟脂肝细胞和多脂肝细胞则由软体动物肝脏的消化细胞演化而来.