用户名: 密码: 验证码:
PARATROCHAMMINA MINUTISSIMA N. SP. IN BRACKISH, MARIN
详细信息   在线全文   PDF全文下载
摘要

Paratrochammina minutissima n. sp. is described from Abraxas and Ace Lakes in the Vestfold Hills, East Antarctica. The species is characterized by very small size (120 μm diameter), 4½ chambers in the final whorl, weak adherence of particles to the tectin chamber lining and a relatively prominent proloculus. Similar species occur in the fully marine environment and often in the abyssal ocean. Subfossil tests were observed in sediment cores from Abraxas Lake and nearby Ace Lake. Apparently, living specimens also occurred in plankton samples from Abraxas Lake, possibly indicating a lifestyle partly attached to zooplankton or floating debris, or floating unattached on density surfaces within the meromictic lake. The distribution of subfossil Paratrochammina minutissima in the sediments of Ace Lake was consistent with a marine origin for the species, while the distribution in the Abraxas Lake sediment indicated that the lake might predate the last glacial maximum.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700