The worm Palaeoscolex from the Cambrian of NW Argentina: extending the biogeography of Cambrian priapulids to South America

Over one hundred years of palaeontological research in northwestern Argentina has provided extensive knowledge of Andean lower Palaeozoic fossil assemblages, with trilobites, graptolites, brachiopods and echinoderms being among the most prominent groups. This record is enriched by the recent discovery of soft-bodied worms in Cambrian outcrops of northwestern Argentina. Palaeoscolex sp. cf. P. ratcliffei from the Furongian Lampazar Formation in Jujuy is described, considerably expanding the biogeographical range of this genus and filling the distributional gap, between the well-known early–middle Cambrian occurrences of Palaeoscolex and those of its Ordovician species.     

Expanding the utility of Uranium-series dating of speleothems for archaeological and palaeontological applications

Uranium-series (U-series) dating of speleothems is frequently used for palaeoclimate studies but its archaeological and palaeontological applications are limited to stratigraphically significant speleothem formations, such as flowstones, to provide maximum and minimum temporal points. This study targeted soda straw stalactites for U-series dating. In contrast to other speleothem formations, soda straw stalactites are fragile, have typically short life spans (usually only years but rarely up to a few hundred years) and are frequently incorporated into cave deposits. Results of thermal ionisation mass spectrometry (TIMS) U-series dating of soda straw stalactites from palaeontological excavations at Blanche Cave, South Australia, show that small, dense, clean straws tend to yield ages closest to the time of stratigraphic deposition. A correlation between soda straw U-series ages and radiocarbon ages of charcoal from the site is shown. Multiple soda straw age determinations for a single stratigraphic unit are required in order to verify age concordance. In conjunction with other dating methods, U-series dating of soda straw stalactites may help to significantly constrain the age of stratigraphic units and associated archaeological and palaeontological deposits in order to provide more robust chronologies. Here we advocate the collection of soda straw stalactites at future excavations of limestone cave sites.     

厦门大学国学院风波——鲁迅与现代评论派冲突的余波

导致1927年厦门大学国学院解体的两大内因,即因缘北京大学而来的鲁迅与所谓现代评论派的冲突,以及国学院与校长林庆及理科的过节,虽有各种复杂的人事纠葛与性格冲突,本身并无政治上实质性的大是大非,不宜单从鲁迅一面立论,将冲突各方推向反面或视为异类。不过,跳出具体的个人恩怨,此事蕴藏着那一时期中国政治与学术重新分化组合的征兆。面对社会矛盾的不断激化,五四以来笼统的政治派分进一步分解,学则在意见分歧中走向各执一端的狭境。     

清华国学研究院的学术建制及治学精神

清华国学研究院(1925-1929),是在"整理国故"运动中涌现的一个著名学术机构。与同时期其他国学机构相比,清华国学研究院既有援引西学,重建现代学术体系的一面;又有继承儒家教育理想与治学路径,结合西方知识工具,致力于阐发传统学术之特质的一面。因此,清华国学研究院的学术建制,学术社群的治学精神,皆有其鲜明的特性。     

澄江化石地寒武纪的“江湖”

澄江化石地揭示了距今5.3亿年前早寒武纪地球生命快速多样化的独特经历,生命摇篮在短暂的地质间隙中孕育了几乎所有主要动物类群的祖先,是生命历史主要阶段的杰出例证,代表了寒武纪生命大爆发时期独一无二的纪录,是动物迅速多样化的“根”,也是早期复杂海洋生态系统的最佳例证,     

The coral Cothonion from the lower Cambrian of North Greenland

Originally described from the Coonigan Formation of New South Wales, Australia, a second occurrence of the operculate coral Cothonion sympomatum is here described from the Paralledal Formation of North Greenland. Both finds are of late early Cambrian age, Series 2, Stage 4 in the emerging fourfold classification of the Cambrian. The new find supports widespread distribution patterns seen in early Cambrian Small Shelly Fossils, although associated trilobites belong to traditional redlichiid (Australia) and olenellid (Greenland) realms, respectively.