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with this scenario, Danian mollusk-dominated<br />
benthic shelf ecosystems of southern middle<br />
paleolatitudes (Neuquén Basin, Argentina) are<br />
characterized by (1) a stratigraphically limited<br />
low in macrofossil abundances; (2) an increase<br />
in starvation-resistant, nonplanktotrophic deposit<br />
feeders and chemosymbionts; (3) a reduction<br />
in the average body size of individuals;<br />
and (4) individuals with inactive lifestyles being<br />
more common than in the late Maastrichtian.<br />
Return to pre-extinction conditions<br />
of the various synecological attributes occurred<br />
over unequal time spans, indicating that<br />
recovery was uncoordinated with respect to<br />
ecological traits. Global comparison of ecological<br />
patterns suggests that reduced food<br />
supply (1) was a controlling factor in both<br />
hemispheres; (2) affected macrobenthic marine<br />
faunas at various distances from the<br />
Chicxulub impact site; and (3) was more effective<br />
in siliciclastic environments as compared<br />
to oligotrophic carbonate settings.<br />
2008010027<br />
澳 大 利 亚 东 部 下 泥 盆 统 礁 灰 岩 形 成 中 的 微<br />
生 物 影 响 = Microbial impacts on the genesis<br />
of Lower Devonian reefal limestones, eastern<br />
Australia. ( 英 文 ). Adachi N; Ezaki Y. palaeoworld,<br />
2007, 16(4): 301-310<br />
Microbial contributions to reefal limestones<br />
are evident in eastern Australian Lower Devonian<br />
microbial frame/bindstones, red algalmicrobial-stromatoporoid<br />
bindstones, and microbial-stromatoporoid<br />
bindstones. Varied<br />
microbialite textures, such as stromatolites,<br />
thrombolites, and leiolites, originated as accumulations<br />
and partial aggregations of calcimicrobes,<br />
peloids, and micrites, which also<br />
derived from microbial activities. In microbial<br />
frame/bindstones, calcimicrobes (e.g., Rothpletzella<br />
and Wetheredella) and dense micrite<br />
layers covered and bound underlying substrates.<br />
Stabilized substrates promoted the<br />
subsequent construction of layered, domal,<br />
and columnar frameworks, which were produced<br />
by combined accumulations and intermixed<br />
associations of calcimicrobes and micritic<br />
microbialites. Microbes flourished in the<br />
microbial-stromatoporoid bindstones and red<br />
algal-microbial-stromatoporoid bindstones<br />
during repeated growth interruptions of the<br />
framework-building skeletal organisms. Microbes<br />
bored into and eroded the skeletal<br />
frameworks to subsequently leave micritic<br />
envelopes, on which microbial and skeletal<br />
encrustations took place in turn. The importance<br />
of microbial colonization on the skeletal<br />
frameworks was first as subsidiary encrusters<br />
that helped to preserve them from erosion, and<br />
second as modifiers of the spaces suitable for<br />
succeeding encrusters. Partial aggregations of<br />
Renalcis filled in the interstices of the skeletal<br />
and microbial frameworks, thereby enhancing<br />
their rigidity.<br />
The microbial impacts on the genesis of<br />
reefal limestones are: (1) origination of components<br />
(calcimicrobes, peloids, and micrites);<br />
(2) formation of characteristic microbial textures;<br />
(3) main and subsidiary reef construction<br />
and encrustation; and (4) destruction of<br />
these components, textures, and structures, but<br />
also the protection of resultant constructions<br />
in turn. The Lower Devonian reefal limestones<br />
treated herein, surprisingly, preserve excellent<br />
records of a variety of microbial impacts.<br />
Similar effects may also have been common,<br />
although variable in preservation, in other ancient<br />
reefal deposits.<br />
2008010028<br />
显 生 宇 海 洋 生 物 多 样 性 具 双 曲 线 趋 势 =<br />
Phanerozoic marine biodiversity follows a<br />
hyperbolic trend. ( 英 文 ). Markov A V; Korotayev<br />
A V. palaeoworld, 2007, 16(4): 311-318<br />
Changes in marine biodiversity through the<br />
Phanerozoic correlate much better with hyperbolic<br />
model (widely used in demography and<br />
macrosociology) than with exponential and<br />
logistic models (traditionally used in population<br />
biology and extensively applied to fossil<br />
biodiversity as well). The latter models imply<br />
that changes in diversity are guided by a firstorder<br />
positive feedback (more ancestors, more<br />
descendants) and/or a negative feedback arising<br />
from resource limitation. Hyperbolic<br />
model implies a second-order positive feedback.<br />
The hyperbolic pattern of the world<br />
population growth arises from a second-order<br />
positive feedback between the population size<br />
and the rate of technological growth. The hyperbolic<br />
character of biodiversity growth can<br />
be similarly accounted for by a feedback between<br />
the diversity and community structure<br />
complexity. The similarity between the curves<br />
of biodiversity and human population probably<br />
comes from the fact that both are derived<br />
from the interference of the hyperbolic trend<br />
with cyclical and stochastic dynamics.<br />
2008010029<br />
今 日 古 生 物 学 之 我 见 ( 英 文 ) = My opinion<br />
for today’s paleontology. ( 英 文 ). 杨 敬 之 . 微<br />
体 古 生 物 学 报 , 2001, 18(2): 217-218<br />
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