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191.
Kano, Y., Kimura, S., Kimura, T. & Warén, A. (2012) Living Monoplacophora: morphological conservatism or recent diversification? —Zoologica Scripta, 41, 471–488. The molluscs of the class Monoplacophora are classic and probably the most striking case of a ‘living fossil’ in the deep sea. Until the discovery of the first living specimens in 1950s, the group was thought to be extinct since the Devonian period, almost 400 million years ago. Morphological conservatism over a long span of time in a ‘living‐fossil’ lineage may theoretically result in distant but closely resembling taxa, and this idea apparently led some authors to recognise as many as six families and three superfamilies for less than three dozen living monoplacophoran species. However, no genetic or fossil data have been available regarding the history of their diversification. Here we describe Veleropilina seisuimaruae sp. n., the first member of the class from the north‐western Pacific, based on the shell, radular and anatomical characteristics. Phylogenetic analyses of 6‐kb DNA sequences estimate that the divergence of V. seisuimaruae and Laevipilina hyalina, the only other monoplacophoran available for genetic studies, dates back only to the Late Cretaceous, despite their significant morphological differences among the living members of the class. The recent Monoplacophora might have radiated fairly recently from a cryptic lineage with ordinary rates of morphological evolution, possibly after the global deep‐sea anoxia at the Cenomanian/Turonian boundary. 相似文献
192.
“山水林田湖草沙生命共同体”系统保护与修复是我国生态文明建设的重要内容。明确生命共同体的耦合机制,是科学地进行生态保护和修复工作的关键。针对当前生命共同体耦合机制不清、理论和方法不健全的问题,从耦合的视角出发,在小流域尺度上单一生态系统内部生态要素的耦合、流域尺度上不同生态系统之间的耦合、区域尺度上人与自然的耦合三个方面进行整合,在此基础上探讨了多尺度山水林田湖草沙耦合理论,提出了一般性的山水林田湖草沙耦合理论框架。梳理并比较了当前主要的生态系统模型、景观模型、统计学模型以及复合生态系统的多模型耦合方法,综合提出了一个适用于"山水林田湖草沙生命共同体"耦合研究方法。对进一步完善山水林田湖草沙一体化保护修复提出了建议,包括:一是构建多源信息数据库,推进定量化耦合机制研究;二是开展全生命周期监测与评估,探索适应性治理路径;三是强化多元主体参与,完善协同保护机制。 相似文献
193.
Anders Warén 《New Zealand journal of zoology.》2013,40(3):313-324
Abstract Eulimindae (Prosobranchia) of the New Zealand region that parasitise echinoderms are recorded and discussed. Fuscapex ophioacanthicola n.gen. & sp. is parasitic on Ophioacantha sp., Ophieulima fuscoapicata n.sp. is a parasite of Ophioactis profundi Lütken & Mortensen, Punctifera ophiomoefrae n.gen. & sp. lives partly buried among the radial shields of Ophiomoeris projecta Matsumato, and Stilapex sp. is recorded, but not described, from Ophiothrix oliveri Benham (all hosts ophiuroids). Stilifer sp. lives in galls in an undescribed oreasterid (Asteroidea). Annulobalcis marshalli n.sp. is described from Crotalometra rustica (A. H. Clark) (Crinoidea). Eulima infrapatula Murdoch & Suter is transferred to Sabinella Monterosato and recorded from Ogmocidaris benhami Mortensen; Fusceulima goodingi n.sp. is described from Centrostephanus rodgersi (A. Agassiz) (both hosts echinoids). Two earlier records of sea urchin parasites from New Zealand are discussed, and the species are referred to Pelseneeria. 相似文献