Evidence of fungal decay in petrified legume wood from the Neogene of the Bengal Basin,India

Silicified fossil legume woods of Cynometroxylon Chowdhury & Ghosh collected from the Neogene (late Miocene) sediments of the Bengal Basin, eastern India, exhibit fungal decay seldom found in the fossil record. The wood possesses numerous perforate areas on the surface that seem to be the result of extensive fungal activity. In transverse section, the decayed areas (pockets) appear irregular to ellipsoidal in outline; in longitudinal section these areas of disrupted tissue are somewhat spindle-shaped. Individual pockets are randomly scattered throughout the secondary xylem or are restricted to a narrow zone. The aforesaid patterns of decay in fossil wood show similarities with that of white rot decay commonly produced by higher fungi, specifically basidiomycetes and ascomycetes. The host fossil wood harbors abundant ramifying and septate fungal hyphae with knob like swellings similar to pseudoclamps in basidiomycetes, and three-celled conidia-like reproductive structures. This record expands our current knowledge of wood decaying fungi-host plant interaction in the Neogene tropical forests of Peninsular India.     

The vermiculate surface pattern in brow ridges of Australopithecines and other very ancient hominids

A convoluted surface pattern of fine ridges, pits, and grooves characterized the brow ridges of Australopithecines and other very ancient fossil hominids. This vermiculate configuration terminated rather abruptly just below the fronto-zygomatic suture in Australopithecines. It was resistant to oriented cracking from weathering or fractures, contrasting with the smooth but structurally oriented zygomatic bone adjacent to it. The pattern apparently developed as individuals matured. The vermiculate pattern seems to have been a feature of brow surface in hominids through much of their identifiable history, despite substantial changes in shape and size of the supraorbital region during human evolution. Limitations on the area of vermiculate surface in Australopithecines suggest that the pattern was associated in some yet undetermined manner with overlying soft tissues. This gives evidence on the cause and functional significance of the vermiculate pattern in Neandertal and modern crania. Problems of describing surfaces as “vermiculate” are raised by observation of elaborations of surface relief on two individuals.     

Symbiotic crabs maintain coral health by clearing sediments

Stony corals are the foundation of coral reef ecosystems and form associations with other reef species. Many of these associations may be ecologically important and play a role in maintaining the health and diversity of reef systems, rendering it critical to understand the influence of symbiotic organisms in mediating responses to perturbation. This study demonstrates the importance of an association with trapeziid crabs in reducing adverse effects of sediments deposited on corals. In a field experiment, mortality rates of two species of branching corals were significantly lowered by the presence of crabs. All outplanted corals with crabs survived whereas 45–80% of corals without crabs died within a month. For surviving corals that lacked crabs, growth was slower and tissue bleaching and sediment load were higher. Laboratory experiments revealed that corals with crabs shed substantially more of the sediments deposited on coral surfaces, but also that crabs were most effective at removing grain sizes that were most damaging to coral tissues. The mechanism underlying this symbiotic relationship has not been recognized previously, and its role in maintaining coral health is likely to become even more critical as reefs worldwide experience increasing sedimentation.     

中国直翅目昆虫化石研究现状

截至目前,中国古昆虫学家已研究了分布于中国14省区的50件直翅目化石标本,发表新属38个,新种48个.通过图表提供了我国已发现的直翅目化石名录并介绍了其分布和年代.直翅目化石的研究对昆虫的起源、昆虫与植物的协同演化及古气候的演变等研究提供线索.中国已发现的直翅目化石主要分布于辽、冀、内蒙古三省区,其地质时代大部分为中生代.提出了在化石研究中存在的问题.     

The effect of selected trace metals on the fertilization success of several scleractinian coral species

This study provides new information on the effects of various concentrations of the trace metals copper, lead, zinc, cadmium, and nickel on fertilization success of gametes from the scleractinian reef corals Goniastrea aspera,Goniastrea retiformis, Acropora tenuis, and Acropora longicyathus. The EC50 values (the concentration that reduces the fertilization rate by 50% relative to the control fertilization) for copper effects on fertilization success of these coral species range from 15 to 40 μg/L, which is similar to responses of other marine invertebrates. The EC50 values for lead were 1450–1800 μg/L for the Acropora species, and >2400 μg/L for G. aspera gametes, which indicates that lead was much less toxic than copper. Fertilization responses to zinc and nickel were variable and a significant reduction in fertilization success for A. tenuis gametes was found only at very high cadmium concentrations. The data from this study and other recent research clearly demonstrate that some trace metals impair the fertilization success of gametes from faviid and acroporiid reef corals. Trace metal inputs into reef waters should be limited and controlled to avoid potential interference with sexual reproductive processes of reef corals.     

The first skull of Anthropornis grandis (Aves,Sphenisciformes) associated with postcranial elements

Associated penguin remains found in Bartonian levels of the Submeseta Formation (Seymour Island, Antarctica), including cranium and mandible, both partial tarsometatarsi, and some other fragmentary bones, are analyzed here. This specimen preserves the first cranium reliably assigned to the giant form Anthropornis grandis, and constitutes the first opportunity to taxonomically assign a cranial material to any of the Antarctic penguin species. A discussion of the diet preferences and feeding mechanisms of A. grandis is supported here by three-dimensional paleoneurological and cranial-jaw muscular reconstructions. We propose that A. grandis was a penguin with a voluminous musculature strongly attached to the neck and skull, adapted to chase and hunt fish during diving.     

First Baltic amber megapodagrionid damselfly (Odonata: Zygoptera)

Electropodagrion szwedoi n. gen., n. sp., first Baltic amber megapodagrionid damselfly, is described. The European and North American fossils document a very high diversity and a much wider distribution of this group of damselflies during the Cenozoic than today. A checklist of described fossil species of damselflies of the family Megapodagrionidae is given.     

Implications of imaginal-size variation over the flight period in stoneflies (Plecoptera)

In the present study, the decrease in the mean size of specimens over the species flight period in Plecoptera (12 species, 5 families) was analysed, revealing a significant decrease in the adult mean size, for both males and female, in almost all the species without an extended flight-period pattern. Some of the data show that, in addition to temperature, other regulatory factors must govern these variations. Data support the explanation previously proposed for other insect groups that the individuals with appropriate development emerge at the beginning of the flight period or slightly afterwards, when environmental conditions are suitable, whereas individuals with suboptimal size emerge later trying to increase in size but under pressure to emerge during a specific period of the year. Nevertheless, our data suggest that maximum size does not necessarily coincide with the peak flight period (maximum reproductive possibility).     

中国泥盆纪珊瑚的生物地理及其群落生态

中国泥盆纪可识别出６个珊瑚生物地理区：南天山区、古特提斯区、华南区、华北北缘区、准噶尔－兴安区和保山区。其中,前４４个区均处于当时赤道两侧的低纬度地区,属于老世界大区;而后２个区则可能分别位于北温带和南温带区域内,不在老世界大区范围内。中国泥盆纪珊瑚群大多数都是生活在温暖浅海近南栅上富氧透光带中的群落,其分异度,丰度和密度各有不同,大致属于海浪底栖生物组合ＢＡ３－ＢＡ４;但也有的生活在远岸大陆斜坡